Pre-eclampsia

There's 5 components in it's definition :

a) Blood pressure of >140/90, two readings, 4 hours apart
b) With significant proteinuria
c) Occurs de novo after 20th week of pregnancy
d) In previously normotensive mothers
e) And subsides completely after 6 weeks of delivery


Symptoms of pre-eclampsia :

a) May be asymptommatic
b) Headache
c) Visual disturbances
d) Epigastric/RUQ pain

Signs :

a) Elevated BP
b) Non-dependent, progressive edema
c) Brisk reflexes
d) Ankle clonus
e) SFH less than expected for POG

Eclampsia - convulsions occuring in mothers with well-established pre-eclampsia

Risk factors

Primigravida
Having a child with a new father
Family history (1st degree relatives)
Vascular disease (AI vasculitis, diabetes)
Large placenta (DM, multiple gestation)
Chronic pre-existing hypertension
Renal disease

Screening for Pre-eclampsia

A doppler USG is able to pick up an abnormal notch pattern during uterine artery waveform analysis for pregnancies with incomplete/inadequate trophoblastic invasion.
Hence, it's a useful piece of information for mothers with high risk of developing pre-eclampsia based on medical and obstetric h/o.
However, it has limited diagnostic potential for those of low-risk.

Screening for PE has been condemmed for creating unneccessary anxiety and worry in mothers since there's no proven method to prevent it.
Previously, low dose aspirin (75mg) daily is said to be able to prevent PE, but based on recent studies, it doesn't.
However, some studies also concluded that it might be more useful to be given in larger group of high-risk mothers, given at night, a dose of 150 mg daily (prolonging bleeding time)

Management

In health/antenatal clinics/OPD -> mothers with BP 140/90 or greater and 2+ proteinuria -> to be admitted for diagnosis of Pre-eclampsia.
Investigations done :

Full blood count (Hematocrit and Platelets)
Urine FEME
24 hrs urinary protein and creatinine
BUSE and Creatinine
Liver function test
Coagulation profile

USG for fetal growth, amniotic fluid and doppler studies

Antihypertensive therapy - aim is to reduce BP hence preventing cerebrovascular events, at the same time, not compromising blood flow to fetus.
Labetalol (blocks both alpha and beta-receptors), proven to be safe in pregnancy, given orally/IV.
Nifedipine (calcium channel blockers), rapid action but can cause severe headache, mimicking worsening PE.
Methyldopa (centrally acting sympatholytics), only given orally and requires 24 hrs for action, also proven to be safe in pregnancy.

In fulminant conditions, IV infusion of hydralazine/labetalol, where dosage is titrated against BP, is given.

Complications of PE usually arises due to failure to recognise deteriorating conditions after delivery, which may lead to multi-organ failure as in DIC, renal failure, ARDS, etc.

Many of times, iatrogenic premature delivery may be required for severe pre-eclampsia. 12mg dexamethasone, twice given 12 hours apart is required to induce fetal lung maturation.
Pre-term delivery by LSCS -> higher risk of DVT -> hence SC heparin is administered and anti-thromboembolic stockings must be given as well.

For any spontaneous/induced labour, avoid using ergometrine for active mangement of 3rd stage (ergots causing elevated BP) and epidural anasthesia also helps controlling BP.

Category: Obstetrics Notes