Exposure to Beta-Blockers in Early Pregnancy May Not Pose Large Cardiac Risks

A recent study found that the use of beta-blockers (β-blockers) in the first trimester of pregnancy was not associated with a significant risk of cardiac malformations or other overall malformations. 

Data were analyzed on women from Nordic health registries (n = 3,577) and the U.S. Medicaid database (n = 14,000) who had hypertensive pregnancies. In the Nordic and U.S. cohorts, 682 (19.1%) and 1,668 (11.2%), respectively, were exposed to Beta-Blockers in the first trimester. Researchers measured the pooled adjusted relative risk (RR) and risk difference per 1,000 persons exposed (RD1,000) for different outcomes. RR associated with β-blocker exposure for any major malformation was 1.07 (95% CI, 0.89 to 1.30) and RD1,000 was 3.0 (CI, −6.6 to 12.6). RR and RD1,000 were 1.12 (CI, 0.83 to 1.51) and 2.1 (CI, −4.3 to 8.4), respectively, for any cardiac malformation, and 1.97 (CI, 0.74 to 5.25) and 1.0 (CI, −0.9 to 3.0), respectively, for cleft lip or palate. Based on U.S. cohort data only, the adjusted RR for central nervous system malformations was 1.37 (CI, 0.58 to 3.25) and the RD1,000 was 1.0 (CI, −2.0 to 4.0). 

Hypertension is becoming increasingly more common in pregnant women, the study authors noted, exposing more women to medications early during pregnancy. And treating the mother is important not only for her health but for the health of the fetus, Joel Ray, MD, MSc, of University of Toronto, stated in an accompanying editorial. 

“Accordingly, beta-blockers should be used in pregnancy when indicated for the treatment of various maternal medical conditions, and labetalol should be a first-line treatment choice for chronic hypertension,” he wrote. 

Athena Poppas, MD, Rhode Island Hospital, Providence, agreed. 

“The overarching point that we try to make with patients, and to educate other clinicians, is we need a healthy mother to have a healthy baby,” Poppas, who was not involved in the present study, told TCTMD. “One of the problems we see sometimes is people undertreat pregnant women for fear that something will happen to the baby.” 

Pappas called the new results “very reassuring” and said, “Physicians should feel confident in prescribing [beta-blockers].” 

The authors of the current study concluded, “Our study cannot exclude an increase in the RR for the less common malformation types, cleft lip or palate and central nervous system malformations. However, the point estimates from our analysis suggest a more modest increase in the RR for these malformations than earlier publications have reported. The potential risks to the fetus must be balanced against the risks to the mother associated with untreated hypertension.”  

Renin-Angiotensin-Aldosterone Profiles in Pregnant Women With Chronic Hypertension 

Objective but Not Subjective Short Sleep Duration Is Associated With Hypertension in Obstructive Sleep Apnea 

Sleep duration and C-reactive protein: Associations among pregnant and non-pregnant women 

Sources: MedPage Today, Annals of Internal Medicine: To β or Not to β? Very Likely OK to β; β-Blocker Use in Pregnancy and the Risk for Congenital Malformations: An International Cohort Study, TCTMD