Beta‐Blockers increase the risk of being born small for gestational age or of being institutionalised during infancy

Abstract

ObjectiveTo compare infant outcomes between mothers with hypertension treated by beta‐blockers alone and by methyldopa alone during pregnancy.DesignHistorical cohort study.SettingSaskatchewan, Canada.PopulationWomen who delivered a singleton birth in Saskatchewan during the periods from 1 January 1980 to 30 June 1987 or from 1 January 1990 to 31 December 2005 (women who delivered between 1 July 1987 and 31 December 1989 were excluded because the information recorded on maternal drug use during pregnancy is incomplete) with a diagnosis of a hypertensive disorder during pregnancy, and who were dispensed only beta‐blockers (n = 416) or only methyldopa (n = 1000).MethodsOccurrences of adverse infant outcomes were compared between women who received beta‐blockers only and women who received methyldopa only during pregnancy, first in all eligible women, and then in women with chronic hypertension and in women with gestational hypertension or pre‐eclampsia/eclampsia, separately. Multiple logistic regression analyses were performed to adjust for potential confounding. Main outcome measuresSmall for gestational age (SGA) < 10th percentile, SGA < 3rd percentile, preterm birth, stillbirth, institutionalisation for respiratory distress syndrome (RDS), sepsis, seizure during infancy, and infant death.ResultsAdjusted odds ratios (aORs) and 95% confidence intervals (95% CIs) for infants born to mothers with chronic hypertension who were dispensed beta‐blockers only, as compared with infants born to mothers who were dispensed methyldopa only, during pregnancy were: 1.95 (1.21–3.15), 2.17 (1.06–4.44), and 2.17 (1.09–4.34), respectively, for SGA < 10th percentile, SGA < 3rd percentile, and being institutionalised during infancy.ConclusionsFor infants born to mothers with chronic hypertension, compared with those treated by methyldopa alone, those treated by beta‐blockers appear to be at increased rates of SGA and hospitalisation during infancy.

Do labetalol and methyldopa have different effects on pregnancy outcome? Analysis of data from the Control of Hypertension In Pregnancy Study (CHIPS) trial

“…Our data are consistent with those of a recent historical cohort study that linked provincial prescription drugs and pregnancy outcomes in Saskatchewan, Canada . Women with chronic hypertension in pregnancy (~75% of the women in CHIPS) taking methyldopa (versus β ‐blockers) had fewer babies who were small for gestation age and/or required hospitalisation during infancy (for respiratory distress syndrome, sepsis or seizure); 300/416 women on β ‐blockers were on labetalol and restricting the analysis to only those women led to similar results .…”

Safe and Effective Use of Pharmacologic and Device Therapy for Peripartum Cardiomyopathy

“…β‐Blockers have been reported to increase the risk of low birth weight or hospitalization during infancy. One cohort study included pregnant women with a diagnosis of hypertensive disorder who received either β‐blockers (n=416) or methyldopa (n=1000) . β‐Blockers were associated with higher rates of small for gestational age (< 10th percentile [odds ratio (OR) 1.95, 95% CI 1.21–3.15], < 3rd percentile [OR 2.10, 95% CI 1.06–4.44]) and hospitalization during infancy (OR 2.17, 95% CI 1.09–4.34) .…”

“…One cohort study included pregnant women with a diagnosis of hypertensive disorder who received either β‐blockers (n=416) or methyldopa (n=1000) . β‐Blockers were associated with higher rates of small for gestational age (< 10th percentile [odds ratio (OR) 1.95, 95% CI 1.21–3.15], < 3rd percentile [OR 2.10, 95% CI 1.06–4.44]) and hospitalization during infancy (OR 2.17, 95% CI 1.09–4.34) . These adverse outcomes necessitate close fetal monitoring in women receiving β‐blockers during pregnancy and the first few months of infancy.…”

“…The β 1 ‐selective blockers bisoprolol or metoprolol succinate should be favored in order to avoid β 2 ‐mediated antitocolytic activity that may occur with carvedilol . Due to the potential risk of intrauterine growth retardation, more frequent fetal growth monitoring should be considered, in addition to observation postpartum for bradycardia …”

“…One cohort study included pregnant women with a diagnosis of hypertensive disorder who received either b-blockers (n=416) or methyldopa (n=1000). 29 29 These adverse outcomes necessitate close fetal monitoring in women receiving b-blockers during pregnancy and the first few months of infancy.…”