MATERNAL HYPERTENSION AND SPONTANEOUS PRETERM BIRTHS AMONG BLACK-WOMEN

Objective: To examine effects of maternal hypertension on spontaneous preterm birth (birth at less than 37 weeks' gestation) among black wom en. Methods: Using hospital discharge summary records from the Nationa l Hospital Discharge Survey between 1988 and 1993, we conducted a case -control study to assess the risk of spontaneous preterm birth among b lack women with chronic hypertension preceding pregnancy and pregnancy -induced hypertension. Logistic regression was used to derive odds rat ios (ORs) and 95% confidence intervals (CIs). Results: Preterm births were almost two times more likely for women with pregnancy-induced hyp ertension (OR = 1.8; 95% CI, 1.5, 2.2), more than 1.5 times more likel y for women with chronic hypertension preceding pregnancy (OR = 1.6; 9 5% CI, 1.3, 2.1), and more than four times more likely for women with pregnancy-aggravated hypertension (OR = 4.4; 95% CI, 2.9, 6.7) compare d with normotensive women. Preterm births also were associated signifi cantly with antepartum hemorrhage, poor fetal growth, marital status, and source of payment. The odds of preterm birth by maternal hypertens ion were increased among women with chronic hypertension and genitouri nary infection, whereas the odds of preterm birth were reduced among w omen with pregnancy-induced hypertension and genitourinary infection. Conclusion: These findings are important in demonstrating the relation between type of hypertension in pregnancy and preterm birth. The rela tionships between maternal hypertension and preterm birth need to be f urther investigated to provide some guidelines in the management of hy pertension in pregnancy and assessment of prenatal care compliance for black women, particularly when genitourinary infection is present. (C ) 1998 by The American College of Obstetricians and Gynecologists.