Preeclampsia-epilepsy link sparks early delivery debate

BABIES born to mothers with preeclampsia have an increased risk of developing epilepsy, researchers have found.

A Danish study of 1.5 million children found preeclampsia was a risk factor for babies born at term or post-term, with the highest risk among those with a birth weight below the 10th percentile.

The study found babies born at term to mothers with mild preeclampsia were at a 16% increased risk of developing epilepsy, while those exposed to severe preeclampsia had a 41% increased risk.

The outcome was worse for babies born post-term, with mild preeclampsia resulting in a 68% increased risk and a 2.5-fold risk in those born to mothers with severe preeclampsia.

The finding comes as the Society of Obstetric Medicine of Australia and New Zealand released guidelines recommending delivery for mothers with preeclampsia by 37 weeks’ gestation.

Lead author Dr Sandra Lowe, obstetric physician at the Royal Hospital for Women in Randwick, NSW, said: “In general, we’d recommend delivery by 37 weeks for those with preeclampsia, rather than prolonging the pregnancy.”

There was no evidence in the study that treating preeclampsia made any difference to epilepsy risk, she added.

Mild preeclampsia entails the mother having hypertension and proteinuria less than 0.3 g over 24 hours. Severe preeclampsia results in severe hypertension early in pregnancy, eclampsia, poor foetal growth and seizures.

However, Dr Ted Weaver, president-elect of the Royal Australian and New Zealand College of Obstetricians and Gynaecologists, said each individual had to be treated on a case-by-case basis because the condition varied greatly in different women.

“The incidence of epilepsy in babies exposed to preeclampsia is still low,” Dr Weaver said.

“If we change practice significantly and deliver babies early, we are exposing them to other risks such as growth restrictions and breathing difficulties.”

From the study, more than 45,000 children were prenat­ally exposed to preeclampsia, and of these almost 35,000 were exposed to mild preeclampsia.

During 27 years of follow-up, 20,260 cases of epilepsy were identified.

The authors said preeclampsia might cause foetal brain ischaemia and vascular foetal brain lesions, and that it had been shown to be an important risk factor for newborn encephalopathy.

Pediatrics 2008; 122:1072-78.