Seasonal Variation in the Incidence of Severe Preeclampsia in Mediterranean Climatic Conditions

The aim of the study was to evaluate possible involvement of environmental factors in the incidence of preeclampsia. A retrospective observational study on the seasonal variation of severe preeclampsia, derived from the intensive obstetric care unit files over a 48-month period, was undertaken. Obstetrics were studied and all deliveries and number of severe preeclamptic patients were recorded. The extracted data were then divided into four groups, based on the four main seasons of the year. The rates of severe preeclampsia, occurring in each season, were compared. Although there is a trend of higher incidence during summer, statistical difference was not significant (unpaired t -test: p=0.1250 for preeclampsia p=0.1250 for total deliveries, and paired t -test: p=0.0027 for severe preeclampsia p=0.0002 for total deliveries), perhaps due to the small numbers of the studied groups. In this study we found a prevalence of preeclampsia during summer when the weather is warmer than the other seasons. This finding may provide new possible mechanisms in the pathogenesis of preeclampsia