Pregnancy outcomes in women with chronic hypertension: a population-based study.

OBJECTIVE: To determine the pregnancy outcomes associated with maternal chronic hypertension. STUDY
DESIGN: Retrospective, population-based cohort study of maternal and infant discharge records linked to birth records in California from 1991 to 2001 were examined for demographics and pregnancy outcomes, and comparisons were made between those with and without chronic hypertension. One randomly selected pregnancy per subject was included.
RESULTS: The number of women who delivered with chronic hypertension (0.69% incidence) was 29,842. As compared to non-chronic hypertensive patients, fetal and neonatal mortality and in-hospital maternal mortality were increased (ORs and 95% CIs 2.3, (2.1, 2.6); 2.3, (2.0, 2.7); and 4.8, (3.1, 7.6) respectively). Major maternal morbidity was increased: stroke, OR 5.3, (3.7, 7.5); renal failure, OR 6.0, (4.4, 8.1); pulmonary edema, OR 5.2, (3.9, 6.7); severe preeclampsia, OR 2.7, (2.5, 2.9); and placental abruption OR 2.1, (2.0, 2.3). Neonatal morbidity was increased as well: fetal growth restriction, OR 4.9, (4.7, 5.2); prematurity, OR 3.2, (3.1, 3.3); low birth weight, OR 5.4, (5.2, 5.5); very low birth weight, OR 6.5, (6.2, 6.8); and respiratory distress syndrome, OR 4.0, (3.8, 4.2).
CONCLUSION: Pregnant women with chronic hypertension have significantly increased risks of maternal and perinatal morbidity and mortality. Women with this condition should be treated as high risk with appropriate maternal and fetal surveillance.