Seasonal variation in the incidence of preeclampsia based on the time of conception

Approximately 3-8% of pregnancies are complicated by preeclampsia (PE) and complications of
pregnancy-related hypertensive disorders that are the third leading cause of maternal deaths. This study was
conducted to assess the incidence of preeclampsia in women based on month and season of the conception in
northwestern Iran. The present investigation is a descriptive analytic cross-sectional study including all pregnant
women with singleton pregnancies admitted to the Urmia Medical Science University due to preeclampsia, 2007-
2008. From 2824 women with singleton pregnancy, 166 of them had preeclampsia and 2658 did not. In all cases, the
onset of pregnancy was determined and the relationship between month (season) of pregnancy and occurrence
of preeclampsia was studied. The general information, primary characteristics, and the history of the two groups
were collected and compared. The age, gravidity and parity in the affected group were lower and difference was
statically significant. Being nulligravid and having previous abortion was higher in the case group; and the
difference was not statically significant. Preeclampsia incidence increased in cases of conception in warm and hot
season’s esp. in summer. The average temperature of conception is higher in women with preeclampsia but the
difference is not statically significant. Therefore, it is suggested to hold training classes for young couples in order to
avoid such disorders.