From the Guidelines
Propranolol is generally considered safe to use during pregnancy, but it should be used with caution and only when the benefits clearly outweigh the risks. According to the most recent guideline evidence from the American Heart Association/American College of Cardiology joint committee on clinical practice guidelines 1, most beta blockers, including propranolol, are considered safe to use during pregnancy. However, it is essential to closely monitor fetal growth and surveillance for fetal bradycardia, particularly when used in the third trimester or at higher doses.
Some key points to consider when using propranolol during pregnancy include:
- Starting with the lowest effective dose, typically 10-20 mg twice daily for anxiety or 40 mg twice daily for hypertension, with dose adjustments based on response
- Potential risks include intrauterine growth restriction, neonatal hypoglycemia, bradycardia, and respiratory depression
- Close monitoring of fetal growth and maternal blood pressure is essential throughout pregnancy
- Newborns should be monitored for hypoglycemia, bradycardia, and respiratory issues for 24-48 hours after birth if propranolol is used near delivery
It is also important to note that beta blockers, including propranolol, should be avoided during the first trimester if possible, as there is a potential risk of intrauterine growth retardation 1. However, the most recent evidence from 1 suggests that propranolol can be used safely during pregnancy when necessary, and that the benefits of treatment outweigh the risks.
In terms of specific dosing and monitoring, it is recommended to follow the guidelines outlined in the most recent evidence-based guidelines, such as those from the American Heart Association/American College of Cardiology joint committee on clinical practice guidelines 1. Ultimately, the decision to use propranolol during pregnancy should be made on a case-by-case basis, taking into account the individual patient's needs and medical history. The benefits of propranolol therapy should be carefully weighed against the potential risks, and alternative treatments should be considered if possible.
From the FDA Drug Label
Pregnancy Category C: In a series of reproductive and developmental toxicology studies, propranolol was given to rats by gavage or in the diet throughout pregnancy and lactation At doses of 150 mg/kg/day, but not at doses of 80 mg/kg/day (equivalent to the MRHD on a body surface area basis), treatment was associated with embryotoxicity (reduced litter size and increased resorption rates) as well as neonatal toxicity (deaths) Propranolol hydrochloride also was administered (in the feed) to rabbits (throughout pregnancy and lactation) at doses as high as 150 mg/kg/day (about 5 times the maximum recommended human oral daily dose). No evidence of embryo or neonatal toxicity was noted. There are no adequate and well-controlled studies in pregnant women Intrauterine growth retardation, small placentas, and congenital abnormalities have been reported in neonates whose mothers received propranolol during pregnancy. Neonates whose mothers are receiving propranolol at parturition have exhibited bradycardia, hypoglycemia and/or respiratory depression. Adequate facilities for monitoring such infants at birth should be available Propranolol hydrochloride extended-release capsules should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
Propranolol safety in pregnancy is a concern due to the potential risks to the fetus.
- Embryotoxicity and neonatal toxicity have been observed in animal studies at high doses.
- Intrauterine growth retardation, small placentas, and congenital abnormalities have been reported in human neonates.
- Neonatal bradycardia, hypoglycemia, and/or respiratory depression may occur in infants born to mothers taking propranolol. Propranolol should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus 2, 2, 2.
From the Research
Propranolol Safety in Pregnancy
- The safety of propranolol in pregnancy has been studied in several research papers.
- A study published in 1979 3 found that propranolol therapy in pregnancy was not associated with hypoglycemia, hyperbilirubinemia, polycythemia, neonatal apnea, and bradycardia, but growth retardation was significant in both series.
- However, another study published in 2019 4 compared the efficacy and safety of three oral antihypertensives, including labetalol, for the management of severe hypertension in pregnancy, but did not specifically examine propranolol.
- Other studies have examined the use of propranolol in combination with other medications, such as nifedipine 5, and its use in treating anxiety disorders 6, but these studies do not provide direct evidence on its safety in pregnancy.
- A study published in 1982 7 reviewed the psychiatric side effects of antihypertensive drugs, including propranolol, but did not focus on its safety in pregnancy.
- Overall, the available evidence suggests that propranolol may be associated with growth retardation in pregnancy, but more research is needed to fully understand its safety profile.