Risks and benefits of beta-receptor blockers for pregnancy hypertension: overview of the randomized trials.

OBJECTIVE

Examine the benefits/risks of beta-blockers for pregnancy hypertension.

STUDY DESIGN

Meta-analysis of relevant trials identified by comprehensive literature review (1966-97).

RESULTS

Included were 30 trials for pregnancy hypertension, and four others for perinatal outcomes only. For mild chronic hypertension treated throughout pregnancy (n=2 trials), oral beta-blockers (compared with no therapy) were associated with an inconsistent increase in small for gestational age (SGA) infants (OR 2.46 [1.02, 5.92]). For mild-moderate 'late-onset' pregnancy hypertension (i.e. either chronic treated only late in pregnancy, or pregnancy-induced) (n=8 trials), oral beta-blockers (compared with no therapy) were associated with a decrease in severe hypertension (OR 0.27 [0.16, 0.451), borderline decrease in development of proteinuria (OR 0.69 [0.48, 1.02]), decrease in RDS (OR 0.33 [0.13, 0.85]), but a borderline increase in SGA infants (OR 1.47 [0.96, 2.26]). Beta-blockers were equivalent to other agents (n=15 trials). For severe 'late-onset' pregnancy hypertension (n=5 trials), i.v. labetalol produced less maternal hypotension (OR 0.13 [0.03, 0.71]) and fewer cesareans (OR 0.23 [0.13, 0.63]) than i.v. hydralazine/diazoxide.

CONCLUSIONS

It is not clear that the benefits outweigh the risks when beta-blockers are used to treat mild to moderate chronic or pregnancy-induced hypertension, given the unknown overall effect on perinatal outcomes. For severe 'late-onset' pregnancy hypertension, i.v. labetalol is safer than i.v. hydralazine or diazoxide.