Influence of seasonal variation on pregnancy-induced hypertension and/or preeclampsia.

Seasonal variation of temperature and humidity are said to influence the incidence of hypertensive disorders of pregnancy. The aim of this study was to determine if temperature and humidity exert any influence on the incidence of pregnancy-induced hypertension and preeclampsia in Kuwait. This is a retrospective study performed in the Maternity Hospital, Kuwait (MHK) in the years 1992-1994. Monthly distribution of all deliveries and those in which the patients had pregnancy-induced hypertension and preeclampsia were recorded. There are some studies including ours which do not show any significant correlation between meteorological factors and hypertensive disorders of pregnancy. We found that the incidence of pregnancy-induced hypertension per 1,000 deliveries was high in June when the temperature was very high and the humidity at its lowest. The reverse was true for the incidence of preeclampsia per 1,000 deliveries, which was high in November when the temperature was low and the humidity high.