BACKGROUND AND PURPOSE:

• Smaller studies have suggested that eclampsia may be associated with future seizure disorder related to cortical injury
• Nerenberg et al. (Obstetrics and Gynecology, 2017) evaluated the incidence rate and relative risk of seizure disorder following eclampsia

METHODS:

• Retrospective population-based cohort study
  • Maternal Eclampsia and Long-Term Seizure study (2002 – 2014)
• Inclusion: women 15-50 years
• Exclusion: women with epilepsy, conditions predisposing to seizure, and those who died within 30 days of the delivery discharge date
• Primary Exposure: Defined as eclampsia, preeclampsia, or gestational hypertension between 20 completed weeks of gestation and 30 days after birth
• Referent Group: Women with no hypertensive disorders of pregnancy
• Primary outcome was the risk of seizure disorder starting >30 days after index birth discharge and not more than 20 weeks into a subsequent pregnancy
• Risk was expressed as an incidence rate and a hazard ratio (HR) with 95% CI
• Multivariable adjustment performed for confounders at the index birth as well as adjusting for traumatic brain injury, stroke, cerebral tumor, aneurysm or hemorrhage, and multiple sclerosis

RESULTS:

• Total of 1,565,733 births were in the final cohort
• 1,615 (0.10%) pregnancies exclusively affected by eclampsia, 17,264 (1.1%) with preeclampsia, 60,863 (3.9%) with gestational hypertension, and 1,485,991 (94.9%) unaffected
• Risk for a future seizure disorder was significantly higher after a pregnancy with eclampsia (4.58/10,000 person-years), compared to a pregnancy without a hypertensive disorder of pregnancy (0.72/10,000 person-years)
  • Crude HR 6.09, 95% CI 2.73–13.60
  • Adjusted HR 5.42 95%, CI 2.42–12.12
• The risk of seizure disorder was doubled in pregnancies affected by preeclampsia
  • Adjusted HR 1.96, 95%, CI 1.21–3.17)
• No association was found in gestational hypertension
  • Adjusted HR 1.01, 95% CI 0.71–1.43

CONCLUSION:

• Authors observed an approximately six times higher risk of a future seizure disorder following eclampsia although the absolute risk is still very small
• Mechanism unknown, but possibly related to cerebral edema leading to permanent cortical injury
  • Would explain why risk was higher in eclampsia than preeclampsia but absent in women with gestational hypertension where endothelial dysfunction is minimal

Learn More – Primary Sources:

Long-term Risk of a Seizure Disorder After Eclampsia

Related ObG Topics:

Eclampsia and Role of Magnesium Sulfate

Labetalol or Nifedipine for Chronic Hypertension in Pregnancy?

ACOG Guidance: Emergency Treatment for Severe Hypertension in Pregnancy