Seizure Prophylaxis in Pre-Eclampsia: Is it Needed?
ABSTRACT & COMMENTARY
Synopsis: Withholding anticonvulsants in hypertensive pregnant women who do not have clinical features of central nervous system involvement will not result in a high rate of eclamptic seizures.
Source: Brown MA, Buddle ML. Hypertens Preg 1998; 17:13-21.
To determine the incidence of eclampsia in pre-eclamptic women when seizure prophylaxis is withheld, Brown and Buddle studied maternal and fetal outcomes in 1099 pre-eclamptic women cared for between 1987 and 1995 at an Australian hospital. Intravenous phenytoin followed by oral phenytoin until five days after delivery was given only to women with pre-eclampsia who manifested neurological features, including hyperreflexia with clonus, repeated visual scotomata, or severe headaches with hyperreflexia. Of the 140 (13%) women who received seizure prophylaxis, none convulsed. Eclampsia did occur in four women-two who had no evidence of pre-eclampsia until they seized and two who had pre-eclampsia but no evidence of central nervous system involvement. Overall, eclampsia was observed in two out of 959 cases (0.2%) of pre-eclamptic women who were not thought to need seizure prophylaxis and in one out of 175 cases (0.6%) of women with both hypertension and proteinuria. Brown and Buddle conclude that withholding anticonvulsants in hypertensive pregnant women who do not have clinical features of central nervous system involvement will not result in a high rate of eclamptic seizures.
COMMENT BY STEVEN G. GABBE, MD
Is it safe to withhold seizure prophylaxis from women with pre-eclampsia if they do not manifest neurologic symptoms such as hyperreflexia, headache, or scotomata? This retrospective analysis of prospectively collected data by Brown and Buddle attempts to answer this question. Of the pre-eclamptic women who did not receive seizure prophylaxis, 19% had proteinuria, 19% had severe hypertension (systolic blood pressure £ 170 mmHg and/or diastolic blood pressure £ 110 mmHg), 8% abnormal liver function tests, and 11% thrombocytopenia. Eclampsia occurred in two women in this group-one a multipara without proteinuria who seized during labor at 39 weeks and another who convulsed two hours after admission at 41 weeks gestation.
Two studies have demonstrated that the risk of eclampsia is approximately 1.5% if anticonvulsants are withheld from all pre-eclamptic women. Given the relative safety of seizure prophylaxis with phenytoin and magnesium sulfate and their established efficacy, it appears difficult to justify withholding treatment from these patients regardless of the manifestation of neurologic symptoms. In a prospective, randomized study, Lucas (N Engl J Med 1995;333:201-205) demonstrated that magnesium sulfate eliminated eclampsia in patients at risk and was a more effective prophylactic agent than phenytoin.
You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
- Award-winning Medical Content
- Latest Advances & Development in Medicine
- Unbiased Content