Pre-eclampsia: the good and bad news
Affecting around one in twenty pregnancies, pre-eclampsia is a leading cause of fetal morbidity and mortality globally. Around half a million babies die as a result of the condition annually. Severe pre-eclampsia, leading to eclampsia characterized by seizures, is also the second leading cause of maternal mortality (after hemorrhage) in most countries: an estimated 76,000 women die from it each year. A diagnosis of this multisystemic disorder has classically been made if hypertension and proteinuria are present. Pre-eclampsia can only be resolved by delivery of the placenta, thus management must weigh the severity of the condition against the risk to the fetus of an induced, premature delivery.
The launch of a rapid test measuring the plasma level of placental growth factor (PLGF), a biomarker of placental function, four years ago offered the possibility of a more timely diagnosis of pre-eclampsia and its severity that could facilitate optimal management for both mother and baby, including the administration of corticosteroids to accelerate fetal lung development prior to premature delivery. The level of PLGF normally rises during pregnancy up to 26 to 30 weeks’ gestation, and then falls until full-term, but its level is abnormally low in women with pre-term pre-eclampsia. Recently the published results of a large multicentre study using this rapid test made very encouraging reading. During the study, PLGF was measured in 625 pregnant women between 20 and 35 weeks gestation with suspected pre-eclampsia. The condition was confirmed in 55% of these women, with outcome being the delivery of the fetus within 14 days. The authors concluded that the test had high sensitivity in women presenting with suspected pre-eclampsia before 35 weeks’ gestation, and indicated need for delivery better than other diagnostic methods.
Although this research is good news for pregnant women and their babies, another aspect of pre-eclampsia has largely been ignored and is not generally known by either health-workers or women themselves, namely the subsequent increased health risk in older women who suffered from pre-eclampsia in pregnancy. A robust meta-analysis has linked the condition with a fourfold increased risk of hypertension, and a twofold increased risk of ischemic heart disease, stroke and venous thromboembolism, later in life. A recent study from Australia found that the endothelial dysfunction associated with pre-eclampsia persists, causing the increased risk. At the very least previous pre-eclampsia should be flagged as important in an older woman’s medical history!