Blood pressure changes during pregnancy in Nigerian women.

The purpose of this longitudinal study was to determine the pattern of blood pressure during pregnancy in Nigerian women. The blood pressure of 189 women from early pregnancy and up to term, during labor and 24 h after delivery were monitored. The mean systolic, diastolic and mean arterial blood pressure were computed and the blood pressure readings were correlated with parity and selected anthropometric and socioeconomic variables. The results showed a decline in blood pressure levels during the mid-trimester of pregnancy with a progressive increase towards term. The highest blood pressures were recorded during the third stage of labor. The mean (+/- 2 SD) of blood pressure was 130/80 mmHg. There was no significant correlation of blood pressure with parity but there was a significant positive correlation with maternal age and Quetelex index after 30 weeks of gestation. As compared to Caucasian women, Nigerian women showed higher levels of diastolic blood pressures. We conclude that: (1) the higher incidence of gestational hypertension in African women may be due to higher levels of resting baseline blood pressures in the women, and (2) pregnant women in our population with persistent elevation of blood pressures above 130/80 mmHg should be closely monitored.