This is certify that the dissertation titled “

TO EVALUATE THE DIAGNOSTIC ACCURACY OF SPOT URINE PROTEIN – CREATININE RATIO AS AN ALTERNATIVE TO 24 HOURS

URINARY PROTEIN IN PREECLAMPSIA AND ITS FETO-MATERNAL OUTCOME

Dissertation submitted to

In partial fulfillment of the requirements for the degree of

M.D BRANCH II

OBSTETRICS AND GYNAECOLOGY Register No.:221716203

THANJAVUR MEDICAL COLLEGE

THE TAMILNADU DR. M.G.R. MEDICAL UNIVERSITY CHENNAI, TAMILNADU

May 2020

CERTIFICATE

This is certify that the dissertation titled “

” is a bonafide work done by Dr.P.JAYAMALA in the Department of Obstetrics and Gynaecology, Thanjavur Medical College, in partial fulfillment of the university rules and regulations for the award of MS degree in Obstetrics and Gynaecology under my guidance and supervision during the academic year 2017-2020.

Dr.C.ANJU PADMASEKAR, MD., OG, Assistant Professor and Guide ,

Dept. of Obstetrics and Gynaecology, Thanjavur Medical College,

Thanjavur

Prof.Dr.R.RAJARAJESWARI,

M.D.,D.G.O.,D.N.B., Guide and Head of the Dept.,

Dept. of Obstetrics and Gynaecology, Thanjavur Medical College,

Thanjavur.

Prof. KUMUDHALINGARAJ,M.D.,D.A, Dean,

Thanjavur Medical College, Thanjavur.

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This is to certify that this dissertation work titled “TO EVALUATE THE DIAGNOSTIC ACCURACY OF SPOT URINE PROTEIN – CREATININE RATIO AS AN ALTERNATIVE TO 24 HOURS URINARY PROTEIN IN PREECLAMPSIA AND ITS FETO-MATERNAL OUTCOME” of the candidate Dr.P.JAYAMALA with Registration Number 221716203 for the award of the degree of in the branch of M.S Obstetrics & Gynaecology. I personally verified the urkund.com website for the purpose of plagiarism check. I found that uploaded thesis file contains from Introduction to conclusion pages and result shows percentage of plagiarism in the dissertation.

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DECLARATION

I solemnly declare that this dissertation titled “TO EVALUATE THE DIAGNOSTIC ACCURACY OF SPOT URINE PROTEIN – CREATININE RATIO AS AN ALTERNATIVE TO 24 HOURS URINARY PROTEIN IN PREECLAMPSIA AND ITS FETO-MATERNAL OUTCOME” was done by me at Dept. of Obstetrics and Gynaecology, Thanjavur Medical College during year 2017-2020 under guidance and supervision of Prof.Dr.R.RAJARAJESWARI,MD.,DGO.,DNB OG.,

This dissertation is submitted to The Tamil Nadu Dr. M.G.R. Medical University towards partial fulfillment of requirements for the award of MS degree in Obstetrics and Gynaecology (BRANCH II).

Dr. P.JAYA MALA, MS Post Graduate Student,

Place: Dept of Obstetrics and Gynaecology,

Date: Thanjavur Medical College, Thanjavur.

ACKNOWLEDGEMENT

I gratefully acknowledge and sincerely thank Prof.Dr.KUMUDHA LINGARAJ, MD.,DA, The dean, Thanjavur Medical College and hospital, Thanjavur for permitting me to conduct the study and use facilities of the institution for my Study.

I am grateful to the Head of the Department, Prof. Dr. R. RAJARAJESWARI, MD.,DGO.,DNB.,OG., Dept. of obstetrics and Gynaecology, Thanjavur Medical College, Thanjavur for being my guide and helping me all through the study.

I Sincerely thank our Prof. Dr. J. PRABHA.,MD.,OG and Prof. Dr. S. UDAYA ARUNA MD., OG for her constant support and guidance throughout the study.

I am bound my ties of gratitude to my respected teacher Dr.C.ANJU PADMASEKAR, MD., OG, for her valuable guidance in conducting this study.

I wish to express my sincere thanks to all the Assistant Professors of our department for their support during the study.

I thanks secretary and chairman of Institution Ethical Committee, Thanjavur Medical College, Thanjavur.

I also thank Dr. MAHESHWARAN., MD., who helped me a lot in doing statistics of my study. I would be failing in my duty, if don’t place my sincere thanks to those patients who were the subjects of my study. Above all I thank God Almighty for His immense blessings.

CONTENTS

S.NO. TITLE PAGE

NO.

1. INRODUCTION 1

2. AIMS AND OBJECTIVES 2

3. MATERIALS AND METHODS 3

4. REVIEW OF LITERATURE 5

5. RESULTS 59

6. DISCUSSION 87

7. CONCLUSION 91

8. BIBILIOGRAPHY 9. ANNEXURE

10. PROFORMA

MASTER CHART

INTRODUCTION

Hypertensive disorder of pregnancy complicates approximately 5- 10% of pregnancies¹ of which preeclampsia occurs in 2-8%. According to WHO in developed countries 16% of maternal death are attributed to hypertensive disorders³. It accounts for high amount of maternal morbidity. It is a major pregnancy complication causing spontaneous or iatrogenic preterm delivery, intrauterine growth restriction, abruption and intrauterine fetal demise which contribute significantly to perinatal mortality and morbidity 8 to 10% of all preterm birth results from hypertensive disorders.

Estimation of proteinuria is essential for making diagnosis, to assess the severity of disease and also for predicting feto maternal outcome in preeclamptic pregnancies. For estimating the amount of protein in urine collection of 24 hour urinary sample is taken as gold standard, but it is time consuming, cumbersome and inconvenient.

Routine simple dipstick urine analysis has low sensitivity, high false positive and false negative results. Also its results are being influenced by maternal hydration status, diurnal variation, presence of infection, exercise etc,.

So we can use random urinary spot protein creatinine ratio instead of 24 hour urinary protein to detect significant proteinuria. In this method urinary protein concentration is divided by GFR independent urinary creatinine concentration.

Therefore it is a useful diagnostic tool.

AIM OF THE STUDY

To evaluate the diagnostic accuracy of spot urine protein-creatinine ratio as an alternative to 24 hours urinary protein in preeclampsia and its feto-maternal outcome.

To study the relationship between the 24 hour urinary protein and random urinary spot protein creatinine ratio in pre eclampsia.

To determine the ability of random spot protein creatinine ratio for prediction of significant proteinuria in pre eclampsia and its feto-maternal complications.

MATERIALS AND METHODS

This study was approved by the research and ethics committee of Thanjavur Medical College,Thanjavur.

STUDY TYPE : PROSPECTIVE COHORT STUDY

STUDY PERIOD :18 MONTHS (JAN 2018- JUNE 2019)

STUDY CENTRE : Department of Obstetrics and Gynaecology, Govt,Rajamirasudhar hospital,

Thanjavur Medical College,Thanjavur.

SAMPLE SIZE : 500 Cases

CONSENT : Written informed consent was obtained from the patient or relatives after explaining the procedure.

INCLUSION CRITERIA:

Antenatal mothers with pre eclampsia of more than 20 weeks gestation.

Systolic Blood Pressure ≥ 140 mmHg or Distolic Blood Pressure ≥90 mmHg Proteinuria ≥1+ by dipstick

EXCLUSION CRITERIA:

Refused participants.

Urinary tract infection-More than 10WBC per high power field Ruptured Membrane-Not catheterized.

Chronic hypertension

REVIEW OF LITERATURE

GENERAL ASPECTS:

Pre eclampsia is a disease involving multiple systems such as renal, hepatic, neurological, coagulation and cardiovascular system etc.

Pre eclampsia is often thought of as a disorder with two components, an abnormal placental implantation with endothelial dysfunction.

INCIDENCE:

The incidence of preeclampsia in nulliparous ranges from 3-10%¹.In multiparous it is variable but lesser than that for nulliparous. It is because the incidence is markedly influenced by race and ethnicity. In India the incidence of pre-eclampsia among hospital patients is about 7 to 10% of all antenatal admission.

In united kingdom the incidence is 10%.In USA 6 to 7%.50% are idiopathic.

RISK FACTORS:

1.Age

Young and nulliparous women < 20 years Maternal age older than 35 years

2.Race

It is high in African and American ethnicity(3%) compared with white women (1.8%)

3. Obesity

BMI Incidence of pre eclampsia

<20 4.3%

>35 13.3%

The possible explanations are increased cytokine mediated inflammation , increased oxidative stress , increased shear stress, dyslipidemia and increased sympathetic activity

1. Prolonged interpregnancy interval > 10 years 2. Family history of preeclampsia

3. Obstetric factors

• Previous history of preeclampsia

• Multifetal gestation

• Hydropsfetalis

• Abnormal uterine artery Doppler at 18-24 weeks 4. Preexisting medical disorders

• Diabetes Mellitus

• Chronic Hypertension

• Renal Disease

• Thrombophilias

• Autoimmune disease 5. Environmental factors

• Smoking decreases the risk of preeclampsia

BLOOD PRESSURE MEASUREMENTS

1. Conventional mercury sphygmomanometer - Gold standard for blood pressure measurement.⁵

2. Use bell of stethescope as it better amplifies the Korotkoff (V) Sound.⁵ 3. The blood pressure level should be taken with an appropriate size cuff length

1.5 times the upper arm circumference or a cuff with a bladder that encircles 80% or more of the arm and width should be 40% of arm circumference.⁵ 4. The cuff should encircle and cover two thirds of the length of the arm.The cuff

should be wrapped around the upper arm with the cuff’s lower edge one inch above the antecubital fossa.⁵

5. Patient should be in sitting posture with her right arm well supported in a horizontal position at the level of heart and her feet supported, after a 10 minute or longer rest period.

6. Inflate the cuff above the systolic pressure as recognized by disappearance of the radial pulse.

7. The pressure in the cuff is gradually reduced while the examiner listens for sounds in the brachial artery with a stethoscope.The pressure recorded as the syslolic pressure as the first soft tapping sounds are heard.

8. As the pressure is reduced still further,the sounds become louder and more distinct.When the artery is no longer constricted and blood flows freely,the sounds can no longer be heard.The pressure at which the sounds disappear is recorded as diastolic pressure.

9. A large cuff should be used for obese patients

10.If the patients lie on their left side and the blood pressure is taken on the right arm , the blood pressure is falsely low by as much as 15 mmHg.

RISK FACTORS FOR PREECLAMPSIA⁸ Maternal or pregnancy related risk factors:

• Primiparity

• Extremes of age

• Obesity and insulin resistance /gestational diabetes

• Smoking

• Multifetal pregnancies

• Preeclampsia in previous pregnancy

• Maternal low birth weight

• Family history of preeclampsia Pre-existing medical disease:

• Pre-gestational diabetes

• Chronic hypertensive or renal disease

• Maternal immunological disease

• Pre-existing thrombophilia, antiphospholipid antibody syndrome.

CLINICAL RISK FACTORS FOR PREECLAMPSIA¹

RISK FACTOR PREGNANCIES

(MILLIONS)

POOLED UNADJUSTED RELATIVE RISK (95%CI)

SLE 2.43 2.5(1.0-6.3)

Nulliparity 2.98 2.1(1.9-2.4)

Age>35 5.24 1.2(1.1-1.3)

Prior stillbirth 0.063 2.4(1.7-3.4)

CKD 0.97 1.8(1.5-2.1)

ART 1.46 1.8(1.6-2.1)

BMI>30 5.92 2.8(2.6-3.1)

Multifetal Gestation 7.31 2.9(2.6-3.1)

Prior abruption 0.29 2.0(1.4-2.7)

Diabetes 2.55 3.7(3.1-4.3)

Prior

Preeclampsia 3.72 8.4(7.1-9.9)

CHTN 6.59 5.1(4.0-6.5)

APLA 0.22 2.8(1.8-4.3)

APLA= antiphospholipid antibody; ART= assisted reproductive technology; BMI= body mass index; CHTN= chronic hypertension; CKD = chronic kidney disease; SLE= systemic lupus erythematosus.

Data from Bartsch,2016.

ETIOLOGY

Preeclampsia has been known as ‘’The Disease of Theories” because the exact course of events that cause the clinical syndrome is not clear. Pregnancy is seen as a “Stress Test” for the vascular system of mother and women those who develop preeclampsia is due to failure of this test.

TWO STAGE THEORY OF PREECLAMPSIA: (RED MANN ET AL)¹⁰ In stage one there is faulty endovascular trophoblastic remodeling of uterine arteries during first half of pregnancy results in placental hypoxia.

In stage two there is systemic release of placental factors because of oxidative stress that causes systemic inflammatory response and endothelial activation culminating in preeclampsia syndrome.

OTHER THEORIES PROPOSED:

1. Impaired trophoblastic invasion 2. Immunological maladaptation 3. Exaggerated inflammatory response 4. Vascular endothelial damage

5. Increased oxidative stress 6. Coagulation abnormalities 7. Angiogenic imbalance 8. Genetic factors

IMPAIRED TROPHOBLASTIC INVASION:

The basic pathology in pre eclampsia is impaired trophoblastic invasion. It may result either from defective invasion or trophoblastic cell death induced after normal invasion. As a result of this, remodelling of spiral arterioles got affected.

The process of interstitial trophoblastic invasion of both the deciduas basalis and the myometrium starts at the centre and spreads towards the margin¹⁹. During the first few weeks of pregnancy some of the interstitial trophoblasts enter the lumina of spiral arterioles in the superficial decidual compartment near placental decidual junction later on deeper in the myometrial compartment.Based on the studies it is found that there is a time interval of one month between endovascular trophoblastic invasion of decidual and myometrial segments respectively^20,22. Based on these the existence of two successive waves of endovascular invasion with a temporary halt at decidual myometrial junction. Normal spiral artery remodeling involves five steps:

Step 1 Endothelial vacuolization.

Step 2 Early media disorganisation and weakening of elastica.

Step 3 Appearance of endovascular trophoblast in the arteriolar Lumen

Step 4 Incorporation of endovascular trophoblast into the vessel wall.This process is associated with fibrinoid deposition Step 5 Endothelial repair and intimal thickening

In preeclampsia the deeper myometrial arterioles do not lose their endothelial lining and musculoelastic tissue. So their mean external diameter is reduced which impairs placental blood flow²⁴. This diminished perfusion and hypoxic environment result in stage two changes.

IMMUNOLOGICAL MALADAPTATION:

Loss of immune tolerance or immune dysregulation is an another theory for preeclampsia syndrome.

During implantation the extra villous trophoblast invade the maternal decidua which is infiltrated by abundant NK cells²⁸, macrophages and CD3 TCells.

These trophoblastic cells are allogenic which express three class I molecules HLA- G,HLA-E and HLA-C. Among these three HLA-G and HLA-E show very limited polymorphism .Only HLA-C is highly polymorphic²⁹. Among the identified NK receptors it is the KIR family (Killer Immunoglobulin like Receptors )will bind with HLA- C.This particular combination of maternal KIR with paternal HLA-C has a main influence on the production of chemokines by NK cells³⁴. So preeclampsia will arise as a result of unfavourable combination of maternal KIR and paternal HLA-C.

EXAGGERATED INFLAMMATORY RESPONSE:

The two main point of contact between maternal and fetal immune system are 1. The systemic immune response between maternal blood and

syncytiotrophoblast

2. The local immune response between maternal decidua and extra villous trophoblast

The syncytiotrophoblast is entirely devoid of MHC expression Normally CD4+ Th cells differentiate into Th1 and Th2 .Th1 cells produce IFN-gamma associated with inflammatory response .Th2 cells produce IL- 4&5.Normally there is a shift towards Th2 differentiation . In preeclampsia an imbalance in Th1 /Th2 ratio is proposed with deviation toward Th1 response .This causes exaggerated systemic inflammatory response in preeclampsia.

VASCULAR ENDOTHELIAL DAMAGE:

Maternal serum and placental levels of sFlt-1(soluble fms like tyrosine kinase-1) are increased in preeclampsia. It is synthesized from the placenta in response to ischemia which binds with VEGF and PLGF³⁵.As a result of this the levels of VEGF and PLGF are reduced which ultimately affects endothelial function.

COAGULATION ABNORMALITIES:

Significant alterations in prostanoid production occurs in women with preeclampsia. An imbalance in production of vasodilator prostaglandin (PGI2) and vasoconstricting prostaglandin (TXA2) is suggested.

ANGIOGENIC IMBALANCE:

In preeclampsia there is dispropotion between circulating proangiogenic (VEGF, PLGF-decreased) and anti angiogenic (sFlt1 and soluble endoglin increased) substances.

GENETICS:

The hereditary predisposition is a result of complex interaction of several inherited genes both maternal and paternal³⁹. Those are

1. MTHFR gene

2. Factor V Leiden gene 3. Angiotensinogen gene 4. HLA gene

OXIDATIVE STRESS

Inadequate antioxidant response after initiation of maternal blood flow in intervillous space

Faulty trophoblastic invasion and partial remodelling of spiral arterioles

Placental hypoperfusion

Placental hypoxia and increased shear stress

Increased expression of xanthine oxidase and NADPH oxidase

Increased superoxide generation

Chronic oxidative stress

Apoptosis and necrosis of trophoblast

Release of placental factors into circulation Increased endothelin

Decreased nitric oxide

Altered thromboxane A2 and prostacyclin ratio

5. NOS3 gene 6. Prothrombin gene 7. ACE gene

PATHOGENESIS VASOSPASM

The concept of vasospasm with preeclampsia has been advanced for a century⁵².

Systemic endothelial activation causes vasospasm that elevates resistance to produce subsequent hypertension. Concurrently, systemic endothelial cell injury promotes interstitial leakage and blood constituents including platelets and fibrinogen, are deposited subendothelially and hence uteroplacental insufficiency (Brunner &Gavras 1975)

Endothelial junctional proteins are also disrupted, and the sub endothelial region of resistance arteries undergoes ultrastructural change ^53,54. The much larger venous circuit is similarly involved.

With diminished blood flow because of maldistribution from vasospasm and interstitial leakage, ischemia of the surrounding tissues can lead to necrosis, haemorrhage, and end organ disturbances characteristic of this syndrome. One important clinical correlate to this is the markedly attenuated blood volume seen in women with severe preeclampsia⁵⁵

ENDOTHELIAL CELL INJURY

Injury to systemic endothelial cells is the centre piece of preeclampsia pathogenesis . In this scheme, protein factors – lightly placental- are secreted into the maternal circulation and provoke activation and dysfunction of the systemic vascular resistance.

Many facets of the clinical syndrome of preeclampsia are thought to result from this widespread endothelial cell changes.

Endothelial dysfunction results from "Generalised perturbation of normal maternal intravascular inflammatory adaptation to pregnancy (Redman and Colleagues,1999).

Intact endothelium has anticoagulant properties. Also systemic endothelial cells ¸by releasing nitric oxide, blunt the response of vascular smooth muscle to agonist. Injured or activated endothelial cells may produce less nitric oxide and may secrete substances that promote coagulation and greater sensitivity to vasopressors.

Further evidence of endothelial activation includes the characteristic changes in glomerular capillary endothelial morphology, greater capillary permeability and elevated blood concentrations of substances associated with endothelial activation. Likely, multiple factors in the plasma of preeclamptic women combined to exert these vasoactive effects^56,57.

INCREASED PRESSOR RESPONSES

Pregnant women normally develop refractoriness to infused vasopressor⁵⁸. Women with early preeclampsia however, have enhanced vascular

reactivity to increased norepinephrine and angiotensin II^59,60. Morever increased sensitivity to angiotensin II clearly precedes the onset of gestational hypertension⁶¹.Paradoxically women who develop preterm preeclampsia have lower circulating levels of angiotensin II ⁶².

PROSTAGLANDINS

Several prostaglandins are thought to be central to preeclampsia syndrome pathophysiology. Specifically, the blunted pressor response seen in normal pregnancy is atleast partially due to diminished vascular responsiveness mediated by endothelial prostaglandin synthesis. For example, compared with normal pregnancy endothelial prostacyclin (PGI2) production is lower in preeclampsia.

This action appears to be mediated by phospholipase A2. At the same time thromboxane A2 secretion by platelets is increased and the prostacyclin:

Thromboxane A2 ratio declines. The net result favours greater sensitivity to infused angiotensin II and ultimately vasoconstriction ⁶³. These changes are apparent as early as 22 weeks gestation in gravidas who later develop preeclampsia⁶⁴.

NITRIC OXIDE

Nitric oxide is a potent vasodilator synthesized from L-Arginine by endothelial cells.

Inhibition of nitric oxide synthesis raises mean arterial pressure, lowers heart rate, and reverses the pregnancy induced refractoriness to vasopressors.

In humans, nitric oxide is the compound that maintains the normal low pressure vasodilated state characteristic of fetoplacental perfusion ^65,66.

The effects of nitric oxide production in preeclampsia are unclear. It appears that the syndrome is associated with decreased endothelial nitric oxide synthase expression,thus resulting in lowered nitric oxide activity.

ENDOTHELINS

Endothelins are 21-aminoacid peptides and potent vasoconstrictors.

Endothelin-1(ET-1)is the primary isoform produced by human endothelium⁶⁷. Plasma ET-1 levels are elevated in normotensive pregnant women but women with preeclampsia have even higher levels ⁶⁸

According to Tailor and Roberts (1999), the placenta is not the source of increased ET-1 concentrations and they likely arise from systemic endothelial activation. Interestingly treatment of preeclamptic women with magnesium sulphate lowers ET-1 concentrations ⁶⁹. And in animal studies, sildenafil reduces ET-1 concentrations ⁷⁰.

OXIDANTS AND ANTIOXIDANTS

A work by Hubal et al have confirmed that pre-eclampsia may have its origin in a disturbed oxidation mechanism. Increased free radical in Preeclampsia causes endothelial damage.

PLACENTAL PROTEINS

Corticotrophin releasing factor, HCG, Activin A & inhibin A are said to play a role in pathogenesis of Gestational Hypertension.

ANGIOGENIC AND ANTIANGIOGENIC PROTEINS

Placental vasculogenesis is evident by 21 days after conception. The list of pro and antiangiogenic substances involving placental vascular development is extensive and the families of VEGF and angiopoietin are the most studied.

Angiogenic imbalance describes excessive amounts of antiangiogenic factors, which are thought to be stimulated by worsening hypoxia at the uteroplacental interphase. Trophoblast of women destined to develop preeclampsia overproducesatleast 2 antiangiogenic peptides that enter the maternal circulation⁶⁷.

First , soluble fms-like tyrosine kinase 1 (sFlt-1) is a receptor for VEGF.

Elevated maternal sFlt-1 levels inactivate and reduce circulating free placental growth factors (PlGF) and VEGF concentration leading to endothelial dysfunction Importantly sFlt-1 levels begin to rise in maternal serum months before preeclampsia is evident. These high levels in the second trimester are associated with a doubling of the risk for preeclampsia ⁷². This divergence from normal levels appears to develop even sooner with early onset preeclampsia (Vatten,2012).

These factors are also operative in pregnancies complicated by fetal growth restriction (Herraz,2012).

The second antiangiogenic peptide, soluble endoglin (sEng) inhibits various transforming growth factor beta (TGF beta) isoforms from binding to

endothelial receptors. Endoglin is one of these receptors. Decreased binding to endoglin diminishes endothelial nitric oxide-dependant vasodilatation.Serum levels of sEng also begin to rise months before clinical preeclampsia develops ⁷². Interestingly metformin reduces antiangiogenic secretion from human tissues(Brownfoot, 2016).

In one systematic review, third trimester elevation of sFlt-1levels and lower PlGF concentrations correlate with preeclampsia development after 25 weeks gestation ⁷³. Subsequently Haggerty and coworkers (2012) reported that doubling of expressions of sFlt-1 and sEng increased the preeclampsia risk by 39 and 74 percent respectively.

The cause of placental overproduction of antiangiogenic proteins remains an enigma. There is a racial-ethnic difference in their secretion⁷⁴. Concentrations of the soluble forms are not higher in fetal circulation or amniotic fluid of preeclamptic women and their levels in maternal blood dissipate after delivery⁷⁴. Clinical research aims to employ antiangiogenic proteins in the prediction and diagnosis of preeclampsia. One preliminary report described therapeutic apheresis to reduce sFlt-1 levels.(Thadhani, 2016).

UTEROPLACENTAL PERFUSION

Compromised uteroplacental perfusion is almost certainly a major culprit in the greater perinatal morbidity and mortality rates seen with the preeclampsia (Harmon, 2015). Measurement of uterine intervillous and placental blood flow would likely be informative. Attempts to assess these in humans have been

hampered by several obstacles that include inaccessibility of the placenta, the complexity of its venous effluent and the need for radioisotopes or invasive techniques.

Measurement of uterine artery blood flow velocity has been used to estimate resistance to uteroplacental blood flow. Vascular resistance is estimated by comparing arterial systolic and diastolic velocity waveforms. By the completion of placentation, impedance of uterine artery blood flow is markedly decreased, but with abnormal placentation, abnormally high resistance persists⁷⁵. Earlier studies were done to assess this by measuring peak systolic:diastolic velocity ratios from uterine and umbilical arteries in preeclamptic pregnancies. In some cases, but certainly not all, there was higher resistance ⁷⁶.

Another doppler waveform -uterine artery “notching”-has been associated with elevated risks for preeclampsia or fetal growth restriction (Groom, 2009). In the MFMU network study reported by Myatt and colleagues (2012a), however notching had a low predictive value except for early-onset severe disease.

Resistance in uterine spiral arteries has also been measured. Impedance was higher in peripheral than in central vessels-a “ring-like” distribution⁷⁷. Mean resistance values were greater in all women with preeclampsia compared with those in normotensive controls. One study used MR imaging and other techniques who assess placental perfusion ex vivo in myometrial arteries removed from women with preeclampsia or fetal growth restriction (Ong, 2003). In both conditions, myometrial arteries exhibited endothelium-dependant vasodilatory response. Moreover, other pregnancy conditions are also associated with increased

resistance ⁷⁸.

De Almeida Pimenta and colleagues (2014) assessed placental vascularity using a three-dimensional power doppler histogram and described a placental vascularity index. This index value was reduced in women with any pregnancy- associated hypertensive disorders – 11.1 % compared with 15.2% in normal controls.

Despite these findings evidence for compromised uteroplacental circulation is found in only a few women who go on to develop preeclampsia. Indeed, when preeclampsia develops during the third trimester,only a third of women with severe disease have abnormal uterine artery velocimetry (Li,2005).In a study of 50 women with HELLP syndrome,only a third had abnormal uterine artery waveforms⁷⁹.In general,the extent of abnormal waveforms correlates with severity of fetal involvement.

PATHOLOGY

CARDIOVASCULAR CHANGES

Increased vascular permeability,increased peripheral resistance and hypotension lead to significant changes in the cardiovascular system

Due to hypertension and increased peripheral resistance,there is increased load on the left ventricle,this leads to left ventricular dysfunction Increased capillary permeability causes extrapolation of fluid into the extra vascular,especially lungs causing pulmonary edema

Due to vasospasm and shrinkage of intravascular compartment,the blood volume expansion that is expected in normal pregnancy does not occur

Contracted intravascular compartment and expanded extravascular compartment is an important feature of preeclampsia

Extravasation of plasma into interstitial space and vasoconstriction lead tohemoconcentration.Due to these changes,women with preeclampsia are very sensitive to vigorous fluid therapy and acute blood loss and are at risk for pulmonary edema and hypotension

Proteinuria and the resultant hypoalbuminemia lead to reduction in plasma oncotic pressure.This,along with extrapolation of fluid can give rise to edema.

HEMATOLOGICAL CHANGES

Thrombocytopenia occurs in all the different types of hypertensive disorders in pregnancy. This may become severe in severe preeclampsia and HELLP syndrome.

Microangiopathic hemolysis occurs due to endothelial damage,platelet adherence, and fibrin deposition. This results in elevated lactic dehydrogenase (LDH) levels and appearance of schistocytes and spherocytes in the peripheral smear

Intravascular coagulation leads to reduction in levels of factor, antithrombin ,and protein C and S,increase in D-dimers.

RENAL CHANGES

Histological and functional changes occur in the renal system

Swelling of the endothelial cells of the renal glomeruli,obstructing the lumen of capillaries, known as glomerular capillary endotheliosis is a characteristic histological renal lesion in preeclampsia.

Glomerular filtration is reduced due to reduced plasma volume, reduction in renal blood flow because of high resistance, and glomerular capillary endotheliosis.

Proteinuria occurs due to increased permeability of the glomeruli to proteins.Most of the proteins excreted is albumin.

Serum creatinine levels increase.

Uric acid levels are increased due to decreased clearance of uric acid by kidney.

Activation of renin-angiotensin system leads to reduced excretion of sodium and chloride causing sodium retention.

Acute tubular necrosis can occur when there is profuse hemorrhage, hypotension and hypovolemia.

HEPATIC CHANGES

Liver changes in preeclampsia consists of peripheral hemorrhages, vasospasm and infarction around the sinusoids.

Serum glutamic oxaloacetic transaminase(SGOT) and Serum glutamic pyramid transaminase(SGPT) levels increase indicating severe disease.

Hemorrhagic infections can form hematoma.which may extend to become sub scapular hematoma. Rarely this can rupture causing life threatening hemorrhage.

Stretching of the liver capsule(Glisson capsule) due to edema and hematoma causes epigastric pain. Liver involvement also causes nausea and vomiting

CENTRAL NERVOUS SYSTEM CHANGES

Changes in the central nervous system are significant and may lead to convulsions.

Cortical and sub-cortical hemorrhages are the most common lesions in the brain. Softening ,necrosis,neurovascular infarct and hemorrhages are also seen.

Endothelial damage leads to leakage of fluid into the interstitial tissue, causing neurovascular edema and convulsions.Auto regulation of cerebral blood flow is lost,and there is cerebral hyper perfusion causing headache,papilledema and scotoma.

The changes in the brain are termed Posterior reversible encephalopathy syndrome(PRES).Widespread cerebral edema can occur and manifest as confusion and coma.

RETINAL CHANGES

Vasospasm is the most common finding in the fundus.Hemorrhages and educates are seen in severe preeclampsia.

Hemorrhage and educates are seen in severe preeclampsia.Papilledema can also occu.Rarely retinal detachment can occur especially following convulsion.

PLACENTAL CHANGES

Due to the failure of the second stage of trophoblastic invasion.the diameter of the spiral arteries in the endometrium is reduced.

The vessel wall undergoes necrosis and the cell wall is replaced by amorphous material.This progresses to obliteration of the vessels and placental infarction.These changes leads to fetal growth restriction,placental abruption and preterm labor

There is increased apoptosis,necrosis,and degeneration of the trophoblast especially syncytiotrophoblast.More syncytiotrophoblast debris and microparticles are released into the maternal circulation,resulting in inflammation of the endothelium and endothelial dysfunction.

CLASSIFICATION:

Hypertensive disorders of pregnancy classified into four well defined groups:

1. Gestational Hypertension 2. Preeclampsia- Eclampsia 3. Chronic Hypertension

- Essential - Secondary

4. Preeclampsia superimposed on chronic hypertension

DEFINITION :

1.NICE – 2010 GUIDELINES⁶ Pre eclampsia:

De novo hypertension developing after 20 weeks of gestation returning to normal at postpartum with properly documented proteinuria.

Severe Pre-Eclampsia:

Pre-eclampsia with severe hypertension and / or with symptoms, and / or biochemical and / or hematological impairment.

I) ACOG : 2012 ⁴

Gestational hypertension:

• Development of hypertension after 20 weeks.

• Previously normotensive.

• SBP > 140mmHg (or)

• DBP > 90mmHg

• Persistent for 4 hours.

• Returns to normal by 6 weeks postpartum.

Pre-Eclampsia:

Gestational Hypertension

New onset of any of the following

• Proteinuria.

≥300mg/day (or)

Protein creatinine ratio 0.3 Dipstick ≥ 1+

• Thrombocytopenia.

• Altered liver function.

• Renal insufficiency.

• Pulmonary edema.

• Cerebral disturbances

• Visual impairment

Preeclampsia superimposed on Chronic Hypertension

• New onset proteinuria

• Sudden increase in Pre-existing proteinuria

• Sudden increase in blood pressure if o Previously well controlled (or) o Escalation of BP medications.

NICE guidelines divided hypertension into mild, moderate and severe for management purposes.

Systolic BPmm Hg

Diastolic BPmm Hg

Mild hypertension 140-149 90-99

Moderate hypertension 150-159 100-109

Severe hypertension ≥160 ≥110

Pre-Eclampsia ⁵

Non severe Pre-eclampsia Severe Pre-eclampsia

1. Hypertension :

BP ≥ 140/90 mmHg on 2 occasions atleast 6 hours apart 2.Proteinuria:

i) Dipstick ≥1+

ii) Urine Protein : Creatinine ratio ≥0.3

iii) 24 hrs urinary protein ≥300mg /24 hr

i) BP of ≥160mmHg Systolic or

≥110mgHg of

Diastolic on 2 occasions 6hrs apart.

ii) Proteinuria ≥ 5g in 24 hours iii) Oliguria < 500ml/24 hrs iv) Cerebral visual disturbance v) Epigastric pain ,nausea,

vomiting

vi) Pulmonary edema vii)Impaired liver function

viii) Thrombocytopenia ix) Eclampsia

x) IUGR / FGR [ Sibai BM et al]

ATYPICAL PREECLAMPSIA:⁹

Preeclampsia or eclampsia may develop in a women without either hypertension or proteinuria.

CRITERIA

1. GHTplus one or more of the following Symptoms of preeclampsia Hemolysis

Thrombocytopenia (<1 lakh /cu mm)

Elevated liver enzymes two times the upper limit of normal

2. Gestational proteinuria plus one or more of the following Symptoms of preeclampsia

Hemolysis

Thrombocytopenia (<1 lakh /cu mm)

Elevated liver enzymes two times the upper limit of normal

3. Early signs and symptoms of preeclampsia –eclampsia at <20 weeks 4. Late postpartum preeclampsia-eclampsia> 48 hour

Management of Pre-eclampsia:

Depends upon

a) Severity of Pre-eclampsia b) Gestational age of the fetus c) Maternal and fetal status

d) Presence (or) absence of labour e) Level of neonatal services available

CRITERIA FOR SEVERE PREECLAMPSIA⁹

1. Blood pressure of >/=160mmHg systolic or

>/=110mmHg diastolic, recorded on atleast 2 occasions at least 6 hours apart with the patient on bed rest.

2. Proteinuria of >/= 5g in 24 hours.

3. Oliguria < 500 ml in 24 hours.

4. Cerebral visual disturbances.

5. Epigastric pain, nausea and vomiting.

6. Pulmonary oedema.

7. Impaired liver function of unclear aetiology.

8. Thrombocytopenia.

9. Convulsions (eclampsia) Fetal growth restriction.

A.Gestational age ≥ 37 weeks

Patients with mild Pre-eclampsia at ≥ 37 weeks should be delivered. There is no benefit in continuing pregnancy.

B. Gestational age between 24 and 36 weeks:

Depends upon.

Maternal Evaluation:

• Ask for symptoms of severe Pre-eclampsia

• Check for BP 4 times a day

• Daily body weight, urinary dipstick evaluation

• Laboratory evaluation hematocrit with platelet count, LFT (AST, ALT), Serum creatinine, BUN and Serum Uric Acid, 24 hrs urinary protein and spot protein creatinine ratio.

Fetal evaluation:

• Daily fetal movement count

• Biweekly NST and AFI

• Fetal biometry every 3 weeks

• Umbilical and cerebral Doppler fortnightly.

If the initial evaluation is negative the risk of progression is minimal. So continue expectant management till 37 weeks.

If the evaluation shows any abnormality termination of pregnancy can be considered after a course of steroids.

Role of Anti-Hypertensives:

a) NICE guidelines suggest that start anti-hypertensives in women with moderate hypertension with aim to keep BP <150/80- 100mmHg.

b) Mild hypertension with other markers of severe disease.

c) Mild hypertension with co-morbid conditions.

Role of corticosteroids for lung maturity:

If the gestational age is <34 weeks, give Inj. Betamethasone 12mg intramuscularly two doses 24 hours apart.

RCOG green top guidelines shows single course of antenatal steroids reduce the risk of

• Neonatal death by 31%

• RDS by 44%Intraventricular hemorrhage by 46%

(Grade A recommendation evidence level 1++) Delivery:

Induction of labour with prostaglandins and vaginal delivery attempted.

• Continue anti-hypertensive treatment.

• Maintain BP <150/100mmHg

• Epidural analgesia / anesthesia is the procedure of choice.

• Active management of 3rd stage to avoid PPH. Ergometrine is contraindicated.

SEVERE PRE-ECLAMPSIA MANAGEMENT The main objectives of our management are:

a) Seizure prevention b) Hypertensive control c) Delivery of the baby A) Seizure Prevention:

ACOG recommendations4 are all women with severe pre eclampsia should have MgSO4 prophylaxis. MgSO4 is a peripheral anticonvulsant acts by blocking the neuromuscular transmission by decreasing acetyl choline release. The Magpie trial 2002(Magnesium sulphate for prevention of eclampsia) shows 58% risk reduction of eclampsia with magnesium sulphate.

The Multinational Eclampsia Trial Collaborative Group study summarized that MgSO4 is associated with lower incidence of recurrent seizures.

It can be given intravenous (or) intramuscular.

Intravenous regimen

Loading dose : 4 or 6g iv over 20 mins (20%) Maintenance dose (50%) 1- 2gm iv per hour. If convulsions recur 2g slow iv.

Intramuscular regimen: (Pritchard’s regime) Loading dose:

a) Intravenous : 20ml of 20% MgSO4 4gm slow iv

b) Intramuscular : 10ml of 50% MgSO4 (5gm) in each buttock

Maintenance dose:

5gm (50% MgSO4 10ml) deep intramuscular in alternate buttock every 4 hours.It should be continued till 24 hours after delivery (or) after last convulsion whichever is later

Therapeutic level should be maintained at 4-8 mEq/Lit.

Monitoring for magnesium toxicity:

• Urine output should be atleast >30ml / hr.

• Patellar reflex should be present.

• Respiration rate > 14 breaths / minute

Plasma Magnesium

Concentration Effect

8-10mEq/lit Absent patellar reflex First sign of impending toxicity

>12mEq/lit

Respiratory depression and paralysis

ANTIDOTE:

10ml of 10% solution of calcium gluconate intravenous over 3 minutes.

Acute Management of Severe Hypertension:(ACOG 2012)

When the systolic BP is ≥160mmHg or diastolic BP ≥110mmHg and persistent for 15 min it is called severe hypertension.

Treatment

1) IV Labetalol

• First drug of choice

• Combined alpha and beta adrenergic blocker

• Intravenous bolus dose 20-40mg (Maximum 300mg/hr)

• Continuous IV infusion (1-2 mg/min)

2) IV bolus doses of Hydralazine:

• Direct arteriolar smooth muscle dilator

• Intravenous bolus dose starting at 5mg increasing by 5mg every 20 minutes (Maximum 25mg)

3) Oral Nifedipine:

10-20mg repeated every 20 minutes maximum upto 60mg.

Delivery of the fetus:

If the gestational age is ≥34 weeks deliver immediately.

If the gestation age is <24 weeks, it is better to allow early delivery in these patients because expectant management carries a high maternal and perinatal mortality and morbidity.

Sibai et al (1985)5 reported that expectant management causes 16.7%

eclampsia and HELLP syndrome and ATN in 5% of individuals. The overall perinatal mortality was 87%.

Gestational age between 25 weeks and 33 weeks:-

A systematic review suggests that expectant management of severe Pre- eclampsia at these gestational age may give some additional benefit for the fetus at the expense of additional maternal risk. But however an another study named MEXPRE Latin study disproves this concept.

Following guidelines to be practiced during expectant management.

• Hospitalisation

• Daily weight, input output chart

• Daily fetal movement count

• Antihypertensive treatment to be continued

• Course of steroids

• Lab investigations every other day

• Daily NST

• AFI twice weekly

• Umbilical and MCA Doppler twice every week

• Ultrasound for fetal growth once in 2 weeks

Sibai and barton (2007)¹²

Expectant management to be discontinued in the following settings:

Maternal:

• Apperance of imminent symptoms

• Signs of pulmonary edema

• Hypertension refractory to treatment

• Urine output <500ml/24 hours (or) Sr. Creatinine> 1.5mg/dl

• Persistent thrombocytopenia <1 lakh/cu.mm.

• When abruption is suspected.

Fetal:

• Severe fetal growth restriction <5th centile for GA.

• Umbilical artery Doppler shows diastolic flow reversal

• persistant severe oligo (AFI <5cm).

• Fetal demise

• Biophysical profile < 4 done 6 hours apart Delivery:

Mode of delivery depends on gestational age, fetal conditions and favourability of bishop’s score.

Vaginal delivery is preferred by induction of labour with prostaglandins.

Continuous electronic fetal monitoring is must during labour to diagnose fetal distress or hyperstimulation.

In case of cesarean delivery regional anesthesia is the anesthesia of choice, if there is no contraindications such as coagulopathy or thrombocytopenia.

COMPLICATIONS OF PRE-ECLAMPSIA:

1.HELLP Syndrome

WEINSTEIN coined the term HELLP as a unique variant of pre- eclampsia.

Hemolysis

• Abnormal peripheral blood smear (burr cells,schistocytes)

• Elevated bilirubin > 1.2 mg/dl

• Low serum haptoglobin

• Increased LDH > twice the upper limit of normal (>600IU/l) Elevated Liver enzymes:

Elevated AST, ALT > 72 IU/L Low Platelet Count <1 lakh/mm³

MISSISSIPPI CLASSIFICATION³: For assessing the severity

Class I : Severe Thrombocytopenia <50000/mm3 Class II : Moderate thrombocytopenia

Platelet count 50000 to 100000/mm3 Class III : Mild thrombocytopenia

Platelet count 100000 to 150000/cumm

TENNESSEE SYSTEM:¹⁴ Classifies HELLP as

It carries 1% risk of maternal mortality as a consequence of abruptio placentae with DIVC, acute renal failure and pulmonary edema.Maternal Morbidity:

2.DISSEMINATED INTRAVASCULAR COAGULATION(DIC):10-15%

Abnormal vascular endothelial cell function appears to be an important factor in preeclampsia. Primary therapy is based on rapid delivery of the fetus and placenta, although severely thrombocytopenic patients may require platelet transfusion.

The pathophysiology of DIC is complex. The mechanisms that activate or “trigger” DIC act on processes that are involved in normal hemostasis, namely, the processes of platelet adhesion and aggregation and contact-activated (intrinsic) and tissue factor activated (extrinsic) pathways of coagulation⁽⁷¹⁾.

These mechanisms have in common, the capacity in terms of either the magnitude or the duration of the activating stimulus, to exceed normal compensatory processes. Thrombin is persistently or recurrently elaborated and fibrin is formed in the circulating blood. Fibrinogen, various other coagulation factors and platelets are consumed. The fibrinolytic enzyme system is activated and large amounts of FDP are produced, which further impair haemostatic function.

Bleeding, shock and vascular occlusion commonly supervene and produce profound alterations in the function of various organ systems. Normal compensatory processes may become impaired, creating a self-perpetuating

“vicious cycle”. The ultimate outcome is determined by a dynamic interplay between the various pathologic processes and compensatory mechanisms, in other words, fibrin deposition versus fibrinolysis, depletion versus repletion of coagulation factors and platelets; and production versus clearance of fibrin, FDP, and other products of coagulation⁽⁶⁹

3) Abruptio placentae -10-15 % 4) Acute renal failure - 5-8 %

Oliguria in severe preeclampsia is generally due to hypovolemia and responds to increasing the rate of intravenous fluid administration.Once the women is not responding to fluid challenge it is necessary to review the pathophysiology of oliguria.Severely hypertensive women with increased hematocrit needs treatment with vasodilators whereas normotensive or mildly hypertensive with low hematocrit needs aggressive diuresis.

In rare cases oliguria is renal in origin due to Acute tubular necrosis.This usually occurs in the setting of pre eclampsia with severe abruption and DIVC.These patients may require dialysis but recovery is the rule.

5) Pulmonary edema- 6-8 %

It is the most common complication of severe pre-eclampsiausually occurs in the post partum period.It is usually as a result of aggressive use of crystalloids for intravascular volume expansion in a patient with oliguria.

It typically presents as respiratory distress such as dyspnea,tachypnoea and cough with expectoration of pink frothy sputum.On examining the patient there will be a fall in oxygen saturation and bilateral diffuse crepitation on auscultation.

Treatment consists of propped up position,nasal oxygenby mask and furosemide 20-40mg iv every 6 th hourly.There is a dramatic response to furosemide with profuse diuresis and improvement of respiratory symptoms.

6) Adult respiratory distress syndrome -1-2 % 7) Intra cranial hemorrhage

Intracranial bleeding is the leading cause of death in preeclampsia.It is mainly because of under estimation of severity of disease,failure to use antihypertensives leading onto extreme elevations of blood pressure,discharge from the hospital before obtaining adegqate control of hypertension.

8) Death -1 %

KIDNEY IN PRE-ECLAMPSIA

In a normal pregnancy the kidneys undergo considerable vascular changes.

So in preeclampsia the renal system is very important in both the pathogenesis and pathological sequelae of the disease. The classical pathological change associated with pre-eclampsia is “glomerular capillary endotheliosis” which was described by Spargo et al in 1959.

In the early stage of disease there is intracapillary hypercellularity results in capillary dilatation or “ballooning effect”. Then later in the disease the capillaries are longitudinally expanded and attain a “cigarshaped” morphology. This increased capillary cellularity may push some of the loops into the proximal tubule – a phenomenon known as “pouting”.

As a result of this the glomeruli are effectively obstructed giving rise to the bloodless appearance. In severe cases the mesangial cells may infiltrate the basement membrane and ultimately make the membrane thick.

Renal hemodynamics in normal pregnancy & Preeclampsia:

Renal blood flow increased substantially in human pregnancy. It is reported that Effective Renal Plasma Flow (ERPF) and Glomerular Filtration Rate (GFR) increase by 50-55% and 40-60% respectively. These are as a consequence of renal vasodilatation of both the afferent and efferent arteriole without concomitant elevation in glomerular pressure. The stimulus for gestational renal vasodilatation is mediated via nitric oxide pathways. The ovarian hormone relaxin also plays an important role.

In pre-eclampsia on an average there is a 32% reduction in GFR and a 24%

reduction in ERPF compared to normal pregnancy. It is due to selective increase in efferent arteriolar resistance.

Lindheimer (1999) and Moran et al (2003)7 Comparison of renal hemodynamics

Normal Pregnancy

Pre-eclampsia pregnancy

GFR ml/min 133 90

ERPF ml/min 649 487

FF% 20.4 18.7

Renal involvement in pre-eclampsia:

Serum Creatinine:

It is often used as a measure of renal function but it has poor sensitivity because the levels may remain within the normal range till >50% renal function is compromised. Also it levels are affected by diurnal variation and dietary factors.

So as an alternative 24 hour creatinine clearance is used. It relies upon creatinine freely filtered at the glomerulus and minimal tubular secretion. In pregnancy the level rises from 92ml/min to maximum 125ml/min as a result of increased renal perfusion. The average serum creatinine during pregnancy is 0.6mg/dl and value

>0.8mg/dl is suspicious.

Serum Urea (or) Blood Urea Nitrogen:

The levels are influenced by GFR, tubular re-absorption, dietary protein intake etc.

Mean Serum levels of Urea & Creatinine in pregnancy:

Non- pregnant

I trimester

II trimester

III trimester

S. Creatinine Umol/Lit. 73 65 51 47

S. Urea 4.3 3.5 3.3 3.1

Serum Uric Acid:

Although hyperuricemia does not predict the development of preeclampsia, the levels of uric acid correlates well with fetal and maternal morbidity and severity of the renal lesion. The causes of hyperuricemia has not been established definitively.

The proposed mechanisms are a) Decrease in GFR

b) Decreased tubular secretion c) Increased re-absorption

d) Increased placental production secondary to ischemia and trophoblast breakdown.

e) Increased expression of Xanthine oxidase activity . Serum Cystatin C:

This is a newer indicator of GFR which is independent of age, gender and muscle mass. The levels are rised in pre-eclampsia and the increased serum cystatin C correlate well with the severity of glomerular endotheliosis. So it is emerging as a promising marker of renal impairment in pre-eclampsia.

Proteinuria

It is directly proportional to maternal and perinatal mortality, (Harth et al 2000) and morbidity.

It is an important sign of pre eclampsia ⁸⁰. It reflects the glomerular damage that causes leakage of proteins through the basement membrane.

Significant proteinuria is defined by 300mg/24 hours or persistent 30mg/dl (1+dipstick) in random clean catch sample on at least 2 occasions collected 6 hours apart.

The dipstick that has a good, although not perfect, correlation with the protein concentration in the urine. Urine dipsticks can be affected by variable excretion, maternal dehydration and bacteriuria. The correlation of the dipstick with the 24 hours excretion of protein was studied by Meyer et al⁸¹. A 1+ dipstick has a 92% positive predictive value to predict > 300 mg of protein. Approximate equivalence is 1+ = 0.3g/l, 2+ = 1g/l, 3+ = 3g/l, 4+ = >3g/l.

A second rapid method for evaluation of proteinuria is the

protein/creatinine ratio that in the nonpregnant state, correlates well with the 24hour collection. A protein/creatinine ratio of 0.3 has a positive predictive value of 85.5% and a sensitivity of 81.0% for significant proteinuria in the 24-hour collection⁸².Unfortunately, a negative result (<0.3) has a negative predictive value of 47.5%, meaning that about half of the women with a negative result will have significant proteinuria in the 24-hour collection specimen.

In summary, a protein/creatinine ratio >/=0.3 almost always indicates significant proteinuria and a ratio </=0.2 almost always indicates absent or nonsignificant proteinuria. Intermediate values have elevated percentages of false negative and false positive results.

The definitive test for diagnosing proteinuria is a quantitative measurement of total protein excretion in 24-hour urine sample. As per the NICE clinical guideline(2014), if anautomated reagent-strip reading device is used to detect proteinuria and a result of 11 or more is obtained, a spot urinary protein:creatinine ratio or 24-hour urine collection to quantify proteinuria should be done⁶.

The proteinuria of preeclampsia is “nonselective,” meaning that it is a mixture of several proteins of different molecular weight. Proteinuria in preeclampsia characteristically occurs in the absence of either a nephritic (red cells, red cells casts) or a nephrotic (birefringent lipids, wax casts) urinary sediment.

The urinary sediment in preeclampsia is usually unrevealing and in most cases shows an abundance of fine and coarse granular casts. The presence of a nephritic or nephrotic type of sediment must alert the clinician to the possibility of an underlying renal disease.

METHODS OF PROTEINURIA ESTIMATION:

I) ESTIMATION OF 24 HOUR URINARY PROTEIN:

This is the gold standard test for proteinuria estimation. But the following limitations to be considered.

 Collection is cumbersome

 Needs admission of the patient

 Requires about one day (time consuming) for collection

 Subjected to errors such as collection and storage

 The patient compliance is poor

 There will be a delay in diagnosing the severity of the disease.

METHOD:

Patients were instructed to collect urinary sample for 24 hours (from morning 6 am after discarding the first sample to next day morning 6 am including the first morning sample). In our lab quantitative estimation of proteinuria was done by turbimetric method using sulphosalicylic acid.

The advantage is this can be easily performed . It will detect other proteins such as globulin and Bence Jones protein in addition to albumin

Total 24 hour urinary volume is measured and the adequacy of sample was cross checked with creatinine in the sample to the predicted creatinine concentration.

0.5 ml of urinary sample is taken to this 2 ml of 3% sulphosalicylic acid is added. It forms a white turbitidy depends on the amount of protein. It is measured

using Auto Colorimeter Model No:1000 at Optical Density 640 nm. Eg) If OD is 0.05 the amount of protein is 8 mg/ dl likewise a standard method is followed.

Total 24 hour Urinary Protein=

Urinary Protein Concentration mg/dl ×24 hr urinary volume in ml ---

100 II) URINARY DIPSTICK ANALYSIS:

Most common method for screening of proteinuria.

Advantages:

 Inexpensive

 Easily performed

 Rapid results

 Does not require trained personnel.

Disadvantages:

 Results are being influenced by maternal hydration status.

 Diurnal variation of protein excretion

 Exercise

 In the presence of infection

 Urinary contaminates such as blood, phosphates etc.

In our hospital we are using Rapi Scan Reagent strips for urine analysis which gives the results in 60 seconds.

Grades of Proteinuria:

0 Absent

Trace =0.15 to 0.3 g/L 1+=>0.3g/L

2+=>1g/L 3+=>3g/L 4+=>5g/L

III) URINARY SPOT PROTEIN CREATININE RATIO:

It is done in next morning random sample. Here the diurnal variation of urinary specific gravity due to changing GFR affects the urinary protein concentration at different times of the day. To avoid this urinary protein concentration is divided by GFR independent spot urinary creatinine level.

Advantages:

 Can be ordered on OP basis.

 Results available in a short time.

METHOD OF ESTIMATION:

Urinary protein concentration is measured by Sulphosalicylic acid method.

Estimation of urinary creatinine is based on Jaffes principle. On addition of picric acid to the urinary creatinine at alkaline pH it forms a orange colour creatinine alkaline picrate. The magnitude of change in colour is measured using colourimeter at 492nm. The creatinine concentration is calculated by calibrating

against solution of known creatinine. Urinary PCR is calculated by dividing urinary protein concentration by urinary creatinine concentration.

PREVENTION OF PRE-ECLAMPSIA

Various strategies used to prevent or modify preeclampsia severity have been evaluated. Some are listed in the below table. In general, none of these have been found to be convincingly and reproducibly effective.

Some Methods to Prevent Preeclampsia That Have Been Evaluated in Randomized Trials

DIETARY MANIPULATION- low salt diet, calcium or fish oil supplementation

EXERCISE- physical activity, stretching

CARDIOVASCULAR DRUGS-diuretics, antihypertensive drugs

ANTIOXIDANTS- Ascorbic acid (vitamin-C), alpha-tocopherol (vitamin E), Vitamin D

ATITHROMBOTIC DRUGS- low dose aspirin, aspirin/dipyridamole, aspirin + heparin, aspirin+ ketanserin

Modified from Staff,2015.

DIETARY AND LIFESTYLE MODIFICATIONS

Dietary “treatment” for preeclampsia has produced some interesting abuses . A low salt diet was one of the earliest research efforts to prevent preeclampsia . This was followed by years of inappropriate diuretic therapy. Although these practices were discarded, it ironically was not until relatively recently that the first randomised trial was done and showed that a sodium restricted diet was ineffective in preventing preeclampsia.

Regular exercise during pregnancy is linked to a lower risk of developing preeclampsia. Also, in one systematic review, a trend toward risk reduction with exercise was noted. Only a few studies have been randomised, and thus, more research is needed.

Bed Restduring pregnancy is associated with a significantly reduced relative risk of developing preeclampsia. Abenhaim and coworkers (2008), reported a retrospective cohort study of 677 nonhypertensive women hospitalized for bed rest because of threatened preterm delivery. When outcomes of these women were compared with those of the general obstetrical population, bed rest was associated with a significantly reduced relative risk -0.27-of developing preeclampsia.

From two small randomized trials, prophylactic bed rest for 4 to 6 hours daily at home was successful in significantly lowering the incidence of preeclampsia in women with normal pressures.

Calcium supplementation has been studied in several trials, including one by the National Institute of Child Health and Human Development (NICHD) that included more than 4500 low risk nulliparous. Calcium supplementation did not prevent preeclampsia or pregnancy-associated hypertension.

In one meta-analysis,increased calcium intake in high risk women lowered the risk for preeclampsia. However, in aggregate, most of these trials have shown that unless women are calcium deficient supplementation has no salutary effects.

Cardioprotective fatty acids found in some fatty fishes are plentiful in diets of Scandinavians and American Eskimos. Because supplementation with these fatty acids likely prevents inflammatory- mediated atherogenesis , it was posited that they might also prevent preeclampsia. Unfortunately, randomised trials conducted thus far have shown no such benefits from fish oil supplementation.

ANTIHYPERTENSIVE DRUGS

Because of the putative effects of sodium restriction for preeclampsia prevention, diuretic therapy became popular with the introduction of chlorothiazide in 1957. In one meta-analysis of nine randomized trials with more than 7000 pregnancies, women given diuretics had a lower incidence of edema and hypertension but not of preeclampsia. Because women with chronic hypertension are at high risk for preeclampsia, several randomised trials have evaluated various antihypertensive drugs to reduce the incidence of superimposed preeclampsia. A