Maternal and neonatal outcomes of antihypertensive treatment in pregnancy: A retrospective cohort study
by Sascha Dublin, Abisola Idu, Lyndsay A. Avalos, T. Craig Cheetham, Thomas R. Easterling, Lu Chen, Victoria L. Holt, Nerissa Nance, Zoe Bider-Canfield, Romain S. Neugebauer, Kristi Reynolds, Sylvia E. Badon, Susan M. Shortreed
ObjectiveTo compare maternal and infant outcomes with different antihypertensive medications in pregnancy.
DesignRetrospective cohort study.
SettingKaiser Permanente, a large healthcare system in the United States.
PopulationWomen aged 15–49 years with a singleton birth from 2005–2014 treated for hypertension.
MethodsWe identified medication exposure from automated pharmacy data based on the earliest dispensing after the first prenatal visit. Using logistic regression, we calculated weighted outcome prevalences, adjusted odds ratios (aORs) and 95% confidence intervals, with inverse probability of treatment weighting to address confounding.
Main outcome measuresSmall for gestational age, preterm delivery, neonatal and maternal intensive care unit (ICU) admission, preeclampsia, and stillbirth or termination at > 20 weeks.
ResultsAmong 6346 deliveries, 87% with chronic hypertension, the risk of the infant being small for gestational age (birthweight < 10th percentile) was lower with methyldopa than labetalol (prevalence 13.6% vs. 16.6%; aOR 0.77, 95% CI 0.63 to 0.92). For birthweight < 3rd percentile the aOR was 0.57 (0.39 to 0.80). Compared with labetalol (26.0%), risk of preterm delivery was similar for methyldopa (26.5%; aOR 1.10 [0.95 to 1.27]) and slightly higher for nifedipine (28.5%; aOR 1.25 [1.06 to 1.46]) and other β-blockers (31.2%; aOR 1.58 [1.07 to 2.23]). Neonatal ICU admission was more common with nifedipine than labetalol (25.9% vs. 23.3%, aOR 1.21 [1.02 to 1.43]) but not elevated with methyldopa. Risks of other outcomes did not differ by medication.
ConclusionsRisk of most outcomes was similar comparing labetalol, methyldopa and nifedipine. Risk of the infant being small for gestational age was substantially lower for methyldopa, suggesting this medication may warrant further consideration.