Hypertensive disease in pregnancy in Botswana: Prevalence and impact on perinatal outcomes

Abstract

Objectives: Perinatal morbidity in sub-Saharan Africa has been attributed to infection, obstetric emergencies, and preterm birth, but less is known about hypertension in pregnancy. Our objective was to characterize the prevalence of hypertension in pregnancy and the impact of hypertension on perinatal outcomes in sub-Saharan Africa.

Study design: We performed surveillance of obstetric records at eight of the largest public hospitals in Botswana. Women were included in this analysis if they were HIV-uninfected and had singleton gestations and at least one prenatal blood pressure measurement.

Main outcome measures: We measured stillbirth, preterm birth, small for gestational age, and neonatal death in women with and without hypertension in pregnancy.

Results: We included 14,170 pregnancies. Hypertension occurred in 3156 (22.2%) women, with 602 (19.1%) defined as severe. Severe hypertension increased risk of stillbirth (RR 4.4; 95% CI 3.2-6.2), preterm birth (RR 2.5; 95% CI 2.2-2.8), small for gestational age (RR 2.7; 95% CI 2.3-3.1) and neonatal death (RR 5.1; 95% CI 2.9-5.6). Non-severe hypertension increased risk of stillbirth (RR 2.0; 95% CI 1.5-2.7), preterm birth (RR 1.2; 95% CI 1.1-1.3), and small for gestational age (RR 1.6; 95% CI 1.4-1.8). Perinatal outcomes were worse in women with hypertension who had spontaneous preterm birth compared to those who underwent iatrogenic preterm delivery.

Conclusions: Hypertension in pregnancy is common in Botswana and leads to a large number of adverse outcomes. Improved management of hypertension in pregnancy may improve perinatal morbidity and mortality.