The effect of beta-blockers on foetal birth weight in pregnancies in women with structural heart disease: a prospective cohort study

ABSTRACT

Objective:To examine whether treatment with beta-blockers(BBs) in pregnant women with structural heart disease (SHD)resulted in a decrease in foetal birth weight (FBW) in a SouthAfrican cohort.Methods:This was a prospective cohort study conducted in a tertiary-level hospital in Cape Town from 2010 to 2016. Of the 178 pregnant women with SHD, 24.2% received BBs fora minimum of two weeks. Adverse foetal outcomes andmean FBW were compared between the BB groups and subgroups(congenital, valvular, cardiomyopathy and other). Adversefoetal outcome was defined as low birth weight (LBW)<2 500 g, Apgar score<7, premature birth (<37 weeks) and small for gestational age (SGA).Results:BB exposure during pregnancy was found to be associated with a non-significant increased FBW (2 912 vs2 807 g,p=0.347). A significantdecrease(p=0.009) wasnoted in FBW for valvular SHD pregnancies using BBs,while a significant increase (p=0.049) was observed for thesame outcome in the cardiomyopathy subgroup using BBs.A significant increase was observed for SGA (p=0.010) andLBW (p=0.003) pregnancies within the valvular subgroupwhen exposed to BBConclusion:BB use in pregnant women with SHD in a South African cohort showed no association with a decrease in FBW or an increase in adverse foetal outcomes when compared to non-BB usage