Seasonal variation in preeclampsia and eclampsia in Kigali

BACKGROUND: Hypertensive disorders complicate up to 10% of all pregnancies. The World Health Organization estimates the incidence of preeclampsia and eclampsia to be higher in developing countries.
OBJECTIVES: To document the prevalence of preeclampsia and eclampsia in Kigali and determine whether seasonality affects the rate.

METHODS: A combined retrospective and prospective study at 2 teaching hospitals in Kigali was performed over a 2-year period. Data was collected through an admission questionnaire for the prospective portion and the same data was collected for the retrospective portion.

RESULTS: There were 19,746 deliveries and 454 cases of preeclampsia and eclampsia giving an overall prevalence of 2.3% (2.0% and 0.3%, respectively). Most of the patients with preeclampsia (62.3%) presented with severe features. Half of the patients were admitted with blood pressure greater than 160/110 mmHg and 65.7% were preterm. Women with preeclampsia were more likely to have chronic hypertension than women with eclampsia (10.9% vs 0%, p=0.047). Two thirds of patients presenting with preeclampsia/eclampsia were admitted during the rainy season (OR 1.36, 1.11 -1.65, p=0.002). Season at conception did not affect the prevalence of preeclampsia/eclampsia at admission. There was also no difference in the severity of the disease based on seasonality.

CONCLUSIONS: The overall prevalence of preeclampsia and eclampsia in Kigali is similar to other developing countries. Seasonal variation was found in Kigali with a higher prevalence in rainy season. Further studies need to be performed to examine whether other diseases are similarly affected by seasonal variation in such as malaria.