Among antihypertensive medications commonly prescribed for pregnant women, all reduced risk for severe hypertension, but labetalol also reduced odds of other poor outcomes, researchers reported.

Jeffrey N. Bone, MS, statistician and PhD candidate in the department of obstetrics and gynecology at the University of British Columbia in Vancouver, Canada, and colleagues conducted a systematic review and meta-analysis of 61 trials covering 6,923 pregnant women to determine which antihypertensive medications were best for controlling nonsevere hypertension.

Outcomes of interest included severe hypertension, proteinuria/preeclampsia, fetal/newborn death, small for gestational age infants and admission to neonatal care.

The commonly prescribed antihypertensive medications analyzed were labetalol, other beta-blockers, methyldopa, calcium channel blockers and mixed/multidrug therapy, and all reduced risk for severe hypertension by 30% to 70% compared with placebo or no therapy, Bone and colleagues wrote.

Compared with placebo or no therapy, labetalol was associated with reduced odds of proteinuria/preeclampsia (OR = 0.73; 95% credible interval [CrI], 0.54-0.99) and fetal/newborn death (OR = 0.54; 95% CrI, 0.3-0.98), the researchers wrote.

Compared with methyldopa (OR = 0.66; 95% CrI, 0.44-0.99) and calcium channel blockers (OR = 0.63; 95% CrI, 0.41-0.96), labetalol was associated with reduced odds of proteinuria/preeclampsia, according to the researchers.

Bone and colleagues found no significant differences for any other therapy in any other outcome, but noted the credible intervals were wide.

When the researchers conducted a trial sequential analysis, they determined that definitive evidence would require 2,500 to 10,000 women per arm for severe hypertension and safety outcomes and 15,000 women per arm for fetal/newborn death.

“It is unsurprising that antihypertensive therapy outperforms, by a large margin, placebo/no therapy in lowering BP. Many national and international guidelines now recommend that practitioners offer antihypertensive therapy to women to normalize BP in pregnancy,” Bone and colleagues wrote. “Notwithstanding neonatal concerns, it may be reasonable to recommend first-line therapy with labetalol, given the additional potential benefits of reduced proteinuria/preeclampsia and perinatal death.”