Use of β-Blocker in pregnancy and risk of fetal cardiac anomalies.

The use of β-Blocker in pregnancy does not increase the risk of fetal congenital cardiac anomalies after adjusting for maternal co-morbidities says the results of a large population basedcohort study conducted by department of research and evaluation at Kaiser Permanente Southern California.

The study was reported as a research letter online April 17, 2017 in JAMA Internal Medicine.

Lewei Duan and colleagues from Kaiser Permanente, California note, “Beta-blockers are the most commonly used class of medication for treating cardiac conditions in pregnant women. Despite the common use of this class of medication, data that support its safety are limited.”

“A recent meta-analysis reported an association between beta-blocker exposure and fetal congenital cardiovascular defects, raising a concern regarding potential teratogenic effects of this class of medication.”

The authors identified 379,238 women through birth records who delivered at Kaiser Permanente, Southern California through a period of 11 years (2003-2014). Of these, 4847 women (1.3%) received β-Blocker during pregnancy as identified by pharmacy dispensing records.

And, 2,628 (0.7%) were exposed during the first trimester of pregnancy.

Most common beta-blockers were labetalol (n = 3357), atenolol (n = 638), propranolol (n = 489) and metoprolol (n = 324). The most common indication for prescribing beta-blockers was hypertension.

Data analysis revealed that women on beta-blockers were older and had higher body mass index(BMI). They also had higher prevalence of chronic comorbidities like hyperlipidemia, diabetes, hypertension, heart failure, a history of arrhythmia and pregnancy complications like preeclampsia and eclampsia.

They also delivered about a week early than those not taking beta-blockers (mean 37.4 weeks vs. 38.9 weeks).

In unadjusted analyses, women on beta-blockers were significantly more likely to have a baby with congenital cardiac malformation as compared to those not taking the drug (P < 0.001).

When after taking into account the confounders like maternal age, BMI, and comorbidities and gestational age at delivery, there was no longer any association between the exposure and the outcome (P = 0.32).

This suggests that the association seen in unadjusted analyses was caused by maternal demographics and other chronic co-morbidities and not due to beta-blockers.

“The previously reported association between beta-blocker use and fetal cardiac anomalies in other studies may be attributed to confounding,” Duan and colleagues concluded. “While these findings do not definitively rule out the possibility of fetal congenital defects in association with beta-blocker use, these results do provide reassurance regarding the use of this class of medication for the treatment of cardiac conditions in pregnant women.”

Access the Abstract here 

Primary source: Duan L, Ng A, Chen W, Spencer HT, Nguyen J, Shen AY, Lee M. β-Blocker Exposure in Pregnancy and Risk of Fetal Cardiac Anomalies. JAMA Intern Med. 2017;177(6):885-887. doi:10.1001/jamainternmed.2017.0608

ACOG releases recommendations for management of acute onset, severe hypertension in pregnancy and postpartum period.

It is estimated that ten million women develop preeclampsia each year around the world, with 76,000 deaths due preeclampsia and related hypertensive disorders.  It is also responsible for 50,000 stillbirths and early neonatal deaths in developing nations.

A woman in developing country is seven times more likely to develop preeclampsia than a woman in a developed country, contributing to 10-25% of all Maternal mortality.

In the United States, preeclampsia complicates approximately 3-5% of pregnancies, accounting for 10-15% of maternal deaths and 3% of perinatal deaths.

ACOG says “Introducing standardized, evidence-based clinical guidelines for the management of patients with preeclampsia and eclampsia has been demonstrated to reduce the incidence of adverse maternal outcomes.”

ACOG committee opinion was published online ahead of print in Journal of Obstetrics and Gynecology.

Women who are pregnant or postpartum presenting with acute onset severe systolic (greater than or equal to 160 mm Hg) as well as severe diastolic hypertension (greater than or equal to 110 mm Hg) require urgent antihypertensive therapy.

Hospitals, doctor’s office and other institutions handling emergencies should initiate treatment with first line drugs within 30-60 minutes of confirming the diagnosis to prevent maternal stroke.

Intravenous labetalol and hydralazine have long been used as the first line drugs in managing hypertensive emergencies in antenatal and postnatal women.

Recent available evidence suggests that immediate release oral nifedipine may also be considered an alternative first line therapy, especially in circumstances when an IV line is not secured. Some studies in recent time have shown that it brings down BP faster than labetalol and hydralazine. Concurrent use of Nifedipine and Magnesium Sulfate requires tertiary care setup and close monitoring of mother’s vital signs.

Use of all these three drugs does not requires cardiac monitoring.

In rare cases all the three drugs, labetalol, hydralazine and nifedipine may fail to relieve acute hypertensive emergency. In such circumstances, expert opinion of maternal-fetal medicine specialist, anesthesiologist and critical care subspecialist is sought. The second line alternative to be considered are nicardipine or esmolol by infusion pump.

Once the blood pressure is stabilized, detail evaluation of maternal and fetal well-being is carried out to make plans for long term drug therapy and timing of delivery.

The American College of Obstetricians and Gynecologists has identified additional resources on topics related to this document that may be helpful for ob-gyns, other health care providers, and patients. It may be viewed at www.acog.org/More-Info/Hypertension In Pregnancy.

The full text of the ACOG recommendations and suggestions can be accessed here.