Seasonal variation and hypertensive disorders of pregnancy in eastern Sudan

The aim of this study was to investigate the seasonal variation and hypertensive disorders of pregnancy in eastern Sudan, in the period between January 2008 and December 2010. The medical files of women attending at Kassala hospital, eastern Sudan with hypertension, with or without proteinuria were retrospectively retrieved. The data of patients with hypertensive disorders of pregnancy were compared with a similar number of controls that were normotensive and non-proteinuric. During the study period, there were 9,578 deliveries; 153 patients had hypertensive disorders of pregnancy, yielding an incidence rate of 1.6%. Of all cases and controls (306), there were 183 (59.8%) deliveries in winter, 84 (27.5%) in summer and 39 (12.7%) in autumn. The highest rate of pre-eclampsia was in winter (1.1%) (CI = 1.1-2.7, OR = 1.7, p = 0.004) and the lowest rate was in autumn (0.2%) (CI = 0.4-1.8, OR = 0.8, p = 0.758.). Our study revealed significant association between the incidence of hypertensive disorders of pregnancy and the winter season (103 (67.3%) vs 80 (52.3%), p = 0.001). Thus, more attention in the winter season might reduce the morbidity and mortality of hypertensive disorders of pregnancy.