Abstract
Objective: To compare maternal and infant outcomes with
different antihypertensive medications in pregnancy
Design: Retrospective cohort study
Setting: Kaiser Permanente, a large US healthcare system.
Population: Women aged 15-49 years with a singleton birth from
2005-2014 treated for hypertension.
Methods: We identified medication e xposure 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 measures: Small for gestational age (SGA), preterm
delivery, neonatal and maternal intensive care unit (ICU) admission,
preeclampsia, and stillbirth or termination at > 20 weeks.
Results: Among 6346 deliveries, 87% with chronic hypertension,
the risk of SGA (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 < 3rdpercentile 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]). NICU 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.
Conclusions: Risk of most outcomes was similar comparing
labetalol, methyldopa and nifedipine. SGA risk was substantially lower
for methyldopa, suggesting this medication may warrant further
consideration.
Funding: National Institute on Child Health and Human
Development grant R01HD082141; Group Health Foundation.
Keywords: antihypertensives, chronic hypertension, comparative
effectiveness, hypertension, labetalol, methyldopa, nifedipine,
pre-eclampsia, pregnancy, preterm delivery, real-world evidence, small
for gestational age
“Tweetable” Abstract: Pregnant women with hypertension who
took methyldopa were less likely to have infants born too small.