Placenta previa and pre-eclampsia: analyses of 1645 cases at medani maternity hospital, Sudan.

A retrospective case-control study was conducted to investigate the risk factors for pre-eclampsia - including the protective effect of placenta previa - at Medani Maternity Hospital, Sudan. Medical files of the patients during the period 2003-2010 were reviewed for age, parity, education level, prenatal care, placenta previa, and hemoglobin level. Women with pre-eclampsia were the cases, and women with normal pregnancy were the controls. There were 54,339 singleton deliveries and 1765 women with pre-eclampsia in the hospital, giving the incidence of pre-eclampsia of 3.2%. The risk factors for pre-eclampsia were; women with age >35 years (OR = 1.4, 95% CI: 1.1-1.8), primiparity (OR = 3.3, 95% CI: 2.7-4.0), para >5 (OR = 3.1, 95% CI: 2.4-4.0), and anemia (OR = 3.3, 95% CI: 2.8-3.9). The risk of pre-eclampsia was inversely increased with education level and prenatal care attendance. The prevalence of placenta previa was 0 (0%) and 55 (3.3%), P < 0.001 in pre-eclamptic and control women, respectively. Placenta previa was a significant protective factor of pre-eclampsia (OR = 0.3, 95% CI: 0.1-0.7). Although, the socio-demographic risk factors for pre-eclampsia observed among women at Medani hospital were similar to those found in other settings; placenta previa was associated with decreased incidence of pre-eclampsia.