Prediction And Prevention of Pre-Eclampsia

OBG-Speculum:    2024                       ISSN no.

Vol -2, Issue -1  

- Dr Manisha Kumar, Dr Bhawana Meena

Preeclampsia (PE) affects 3–10 % of all gestations globally, in severe cases it affects multiple maternal

organs including the kidneys, liver, brain, and the vascular system. It is the second leading cause of

Maternal mortality in developing world and high morbidity even in the developed countries. It

contributes to 15% of the preterm births and is associated with 25% of stillbirths..

Why to screen?

The first wave of trophoblastic invasion takes place at 8-10 weeks, and 2 nd at 11- 16 weeks, when the

cytotrophoblast invades the decidua, & myometrium to remodel the spiral arterioles respectively for

improving the perfusion at maternal fetal interface, specially to exchange oxygen and nutrients. In

absence of cytotrophoblastic invasion, there is hypoxia , leading to release of free radicals which

further jeopardises the placental vascular milieu. Preeclampsia doubles the risk of cardiovascular

diseases later in life. Early identification & management can reduce the complication rate as well as

severity, thus, it is very much necessary to screen due to high magnitude of the problem

Whom to Screen?

HIGH RISK FACTORS (any 1 if present)

•Preeclampsia in previous pregnancy

•Chronic Hypertension or kidney disease

•Autoimmune disease

•Type 1 or type 2 diabetes

MODERATE RISK FACTORS (any 2)

•First pregnancy

•40 years or older

•Pregnancy interval of more than 10 years

•BMI of 30-35 kg/m2

•Family history of pre-eclampsia

•Multi-fetal pregnancy

•IVF conception

But these maternal factors identifies only about 40% of cases of preterm PE and 35% of term PE.

How to Screen?

Mean arterial Pressure

• Average arterial pressure of a cardiac cycle, calculated as 1/3 Systolic +2/3 diastolic BP

• BP - taken with validated automated devices, in the right way & regularly calibrated

• 95 mmHg is taken as cut off in first trimester

Uterine artery Doppler is best test for early detection of pre-eclampsia of placental origin Uterine

artery Doppler velocimetry at 22-24 weeks suggesting, PI above 95th percentile or the presence of

early diastolic notching (unilateral/bilateral) is abnormal and associated with sixfold increase in rate

of pre-eclampsia with sensitivity in range of 20-60%.() The average of the left and right UtA-PI is

used for risk assessment.

3.Biomarkers

3a) PAPP-A: PAPP-A is a metalloproteinase secreted by the syncytiotrophoblast that plays an

important role in placental growth and development through IGF. PE has been shown to be associated

with a low level of circulating PAPP-A, In euploid pregnancies, a PAPP- A MoM value at less than the

5 th percentile (0.4MoM) is present in 8%–23% of women with PE.

3b) PLACENTAL GROWTH FACTOR (PlGF): It’s a glycoprotein-synthesized in villous and extra-

villous cytotrophoblasts having role in Angiogenesis and trophoblastic invasion of the maternal spiral

arteries. PlGF levels decrease many weeks prior to onset of PE, with a substantial decrease 5 weeks

before

3c) Soluble fms like tyrosine kinase (SFLT): It’s a protein produced by placenta and acts by binding

to the receptor binding domains of VEGF and PLGF. Increased level of SFLT levels inactivate and

decrease circulating level PLGF and VEGF resulting in endothelial cell dysfunction. Magnitude of

SFLT-1 levels correlate with disease severity. The sFlt-1/PlGF ratio increases with the severity of PE

and also found in HELLP syndrome . An sFlt-1/PlGF ratio ≤38 can be used to rule-out the development

of PE in the next week in a clinical suspect.

A combination of maternal factors, maternal arterial blood pressure, uterine artery Doppler and PlGF

level at 11–13 weeks appears to be the most efficient screening model for identification of women at

risk of PE.

PREVENTION BY ASPIRIN (Low dose)

Those having one of high risk or two or more of moderate risk factors are recommended to start low dose Aspirin 150mg preferably at bed time.

A SPREE trial conducted in Europe recommend aspirin 150mg daily, starting from 11 to 14 week and up to 36 week, preferably at night time, had significant role in reducing the rate of pre-eclampsia.

RECOMMENDATIONS

·                FIGO adopts and supports Fetal Medicine Foundation in that all pregnant women should be screened & risk-assessed for pre-eclampsia by the first-trimester combined test with  maternal risk factors,  mean arterial        pressure, uterine artery pulsatility index, and placental growth factor as a one-step procedure.

·                 FIGO   adopts  that in high-risk women, identified by the first-trimester combined test, should be started on low  dose aspirin ~150 mg/night at 11–14weeks of gestation until either 36 weeks of gestation, or when pre-eclampsia is diagnosed.

·                In low/middle-income   countries, variations of the first-trimester combined test should be considered with maternal risk factors combined with mean arterial pressure as must. 

·                FIGO encourages for early booking and improving ANC care access by the women & to adopt risk assessment  of PE as integral part of routine 1st trimester evaluation.