BACKGROUND: Antihypertensives, such as beta-blockers, are used for pregnancy @entity101 in the belief these will improve outcome for mother and baby. OBJECTIVES: To assess whether oral beta-blockers are better than placebo, or no beta-blocker, and have advantages over other antihypertensives, for @entity1 with mild to moderate pregnancy @entity101 . SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group trials register (May 2002), MEDLINE (1966 to May 2002), bibliographies of retrieved papers and personal files. SELECTION CRITERIA: Trials comparing beta-blockers with placebo or no therapy, or other antihypertensives, for @entity1 with mild to moderate pregnancy @entity101 . DATA COLLECTION AND ANALYSIS: We extracted the data independently and were not blinded to trial characteristics or outcomes. Whenever possible, we contacted authors for missing data. MAIN RESULTS: Twenty-nine trials (approximately 2500 @entity1 ) are included. Thirteen trials (1480 @entity1 ) compared beta-blockers with placebo/no beta blocker. Oral beta-blockers decrease the risk of severe @entity101 (relative risk (RR) 0.37, 95% confidence interval (CI) 0.26 to 0.53; 11 trials, N = 1128 @entity1 ) and the need for additional antihypertensives (RR 0.44, 95% CI 0.31 to 0.62; 7 trials, N = 856 @entity1 ). There are insufficient data for conclusions about the effect on perinatal mortality or preterm birth. Beta-blockers seem to be associated with an increase in small-for-gestational-age (SGA) @entity1 (RR 1.36, 95% CI 1.02 to 1.82; 12 trials; N = 1346 @entity1 ). Maternal hospital admission may be decreased, neonatal @entity1168 increased and @entity649 decreased, but these outcomes are reported in only a small proportion of trials. In 13 trials (854 @entity1 ), beta-blockers were compared with @entity12833 . Beta-blockers appear to be no more effective and probably equally as safe. Single small trials have compared beta-blockers with @entity2514 , @entity3360 or @entity4768 . It is unusual for @entity1 to change drugs due to side effects. REVIEWER'S CONCLUSIONS: Improvement in control of maternal blood pressure with use of beta-blockers would be worthwhile only if it were reflected in substantive benefits for mother and/or baby, and none have been clearly demonstrated. The effect of beta-blockers on perinatal outcome is uncertain; the worrying trend to an increase in SGA @entity1 is partly dependent on one small outlying trial. Large randomised trials are needed to determine whether antihypertensive therapy in general (rather than beta-blocker therapy specifically) results in greater benefit than risk, for treatment of mild-moderate pregnancy @entity101 . If so, then it would be appropriate to consider which antihypertensive is best, and beta-blockers should be evaluated.

Oral beta-blockers for mild to moderate XXXX during pregnancy.

@entity1 :: ('9606', 'Species') :: ['women', 'infants'] @entity101 :: ('MESH:D006973', 'Disease') :: ['hypertension'] @entity649 :: ('MESH:D012128', 'Disease') :: ['respiratory distress syndrome'] @entity2514 :: ('MESH:D006830', 'Chemical') :: ['hydralazine'] @entity3360 :: ('MESH:D009529', 'Chemical') :: ['nicardipine'] @entity12833 :: ('MESH:D008750', 'Chemical') :: ['methyldopa'] @entity4768 :: ('MESH:D017275', 'Chemical') :: ['isradipine'] @entity1168 :: ('MESH:D001919', 'Disease') :: ['bradycardia']
@entity101 :: (MESH:D006973,Disease) :: ['hypertension']
