Is It Safe To Take Labetalol During Pregnancy?

This medicine may be taken when its benefits to maternal health outweigh its risks.

Written by shreeja pillai
Last Updated on

Labetalol is used for the treatment of high blood pressure in pregnant women. But, how much labetalol is safe to take during pregnancy? This post will give you the answer to that.

Hypertension is a common problem during pregnancy, occurring in about one in every 12 to 17 pregnant women (1). Therefore, medicines such as labetalol may be used after a doctor’s consultation. It is sometimes known by the names Labracol, Normodyne, and Trandate. Since it is among the beta-blocker class of medications, it slows down the heart rate when the blood pressure rises.

Besides treating high blood pressure, it can also be used to treat angina-induced chest pain and prevent hypertension-related heart problems such as stroke and heart attacks (2).

In this post, we will tell you about labetalol and its safety for pregnant women, including its side effects.

Is Labetalol Safe During Pregnancy?

The US Food and Drug Administration (FDA) classified labetalol as a ‘Cat-C’ drug. Studies on rats and rabbits, which were given a far higher dosage than the maximum recommended dosage for humans (MRHD), did not observe any reproducible fetal malformations or drug-related harm to the fetus. However, there are no adequate and well-controlled studies on the effect of labetalol on pregnant women. Hence, the US FDA suggests that labetalol should be used only when the potential benefits outweigh its risks (3).

A clinical trial conducted in India observed (4):

  • A consistent fall in blood pressure (BP) up to 100mmHg or below within an hour of administration
  • No tachycardia or any other maternal side effects were observed
  • No fetal growth restrictions or other effects on the fetus

This study foresees labetalol being considered as the first-line drug for treating hypertension during pregnancy.

Another trial on 104 pregnant women in Kuwait treated with labetalol for hypertension concluded that the recovery was quicker, more efficient, and better tolerated. Also, there was no evidence of intrauterine growth retardation, perinatal death, and neonatal hypoglycemia. However, it observed that the drug intake may ripen the cervix and reduce the latency of labor in some patients (4).

The American College of Obstetricians and Gynecologists (ACOG) states that intravenous labetalol and hydralazine have been considered as the first-line drugs to treat acute-onset, severe hypertension during pregnancy. However, it recommends against using it in women with asthma, heart disease, or congestive heart failure due to a risk of side effects such as neonatal bradycardia (5).

Your doctor might prescribe this drug if its potential benefits outweigh the potential risks.

Is Labetalol Safe During The First Trimester Of Pregnancy?

There are no studies to determine the safety of labetalol during early pregnancy. However, The National Guideline Clearinghouse states that initial antihypertensive therapy should be started with labetalol or nifedipine. It also says that labetalol is a safer drug for women with pre-existing hypertension who are planning to get pregnant (4).

According to a British Medical Bulletin, many physicians opt to change women’s hypertension drug to methyldopa before conception, especially if they cannot discontinue the drug during early pregnancy. Labetalol is considered a safe alternative for those who are intolerant to methyldopa (6).

So, discuss your condition with your doctor, who can prescribe the ideal medication for you. The maximum oral dose that can be given is 2,400mg/day and IV dose 300mg/day.

Can Labetalol Cause Miscarriage?

There are no studies to prove that labetalol can increase the chance of miscarriage during pregnancy.

Does Labetalol Affect The Fetal Heart Rate?

A systematic review of randomized controlled traits says that the available data is inadequate to conclude if labetalol adversely affects fetal or neonatal heart rate and pattern (7). However, a case report involving two infants suggested that prolonged use of labetalol could be responsible for myocardial hypertrophy in neonates, and suggests intravenous glucagon treatment in such cases (8).

Does Labetalol Cause Neonatal Hypoglycemia?

A study conducted on 48 neonates born to mothers receiving labetalol, and 81 neonates born to mothers who received other drugs for hypertension, found that the incidence of hypoglycemia was significantly higher in neonates whose mothers took labetalol. However, two-thirds of the hypoglycemia was asymptomatic and manageable with sugar-fortified milk feeds (9).

A cohort study using data from Medical Analytic extract concluded that infants born to mothers exposed to beta-blockers, such as labetalol, during delivery have a heightened risk of neonatal bradycardia and hypoglycemia (10).

Although labetalol does not cause any significant birth defects, it still has some adverse effects on the neonate.

Side Effects Of Labetalol During Pregnancy

In addition to the adverse effects in neonates, labetalol has the following side effects on the mother (11) (2).

  • Bradycardia, left ventricular failure when exposed to large doses
  • Hypotension
  • Itchy skin or rash
  • Tingling scalp
  • Difficulty in urination

Consult your doctor if you experience any of the symptoms mentioned above.

Can You Stop Taking Labetalol Suddenly During Pregnancy?

You should not stop taking labetalol suddenly as it may cause increased sensitivity to catecholamines, which can lead to tachyarrhythmia, acute hypertensive crisis, and palpitations (11).

Frequently Asked Questions

1. How much is too much labetalol?

The advised dosage of labetalol for adults ranges from 400 to 800mg per day. But if your blood pressure does not decrease, the doctor might increase the dosage upto 2400mg per day (12).

2. Can I take two 100mg labetalol?

Yes. You may be advised to take 2100mg of labetalol, but remember to consult your doctor before taking it to discuss its potential effects on the baby.

If you are pregnant and have hypertension, you may be curious to know how much labetalol is safe to take during pregnancy. Labetalol controls blood pressure by slowing down the heart rate. Although a few clinical trials have been done on the effects of the drug, well-controlled studies on women are not available. The drug is most commonly used to treat severe hypertension, but you should not use it if you have asthma, heart disease, or other such conditions. If your doctor prescribes labetalol to treat your condition, discuss its dosage, benefits, and side effects to ensure complete safety.

This post is for informational purposes only and is not a replacement for a doctor’s consultation. Do not use any medication without talking to your doctor.

References

1. Pregnancy and High Blood Pressure; NIH
2. Labetalol; The National Health Service
3. Product Information-Trandate; The US Food and Drug Administration
4. Sushrut D, and Girija; Labetalol – An Emerging First-line Drug for Pregnancy-induced Hypertension; National Database Of Indian Medical Journals
5. Emergent Therapy for Acute-Onset, Severe Hypertension During Pregnancy and the Postpartum Period; ACOG Committee Opinion; The American College of Obstetricians and Gynecologists
6. Yao Lu, Ruifang Chen, Jingjing Cai, Zhijun Huang, Hong Yuan; The management of hypertension in women planning for pregnancy; British Medical Bulletin
7. Waterman EJ1, Magee LA, Lim KI, Skoll A, Rurak D, von Dadelszen P;Do commonly used oral antihypertensives alter fetal or neonatal heart rate characteristics? A systematic review; NCBI (2004)
8. B N A Crooksa, S A Deshpandea, C Hallb, M P Ward Platta, D W A Milligan;Adverse neonatal effects of maternal labetalol treatment; ADC Fetal & Neonatal Edition;British Medical Journals
9. U.K. Munshi; A.K Deorari, V.K. Paul, and M.Singh; Effects Of Maternal Labetalol On The Newborn Infant; Indian Academy Of Pediatrics
10. Brian T. Bateman, et al.; Late Pregnancy β Blocker Exposure and Risks of Neonatal Hypoglycemia and Bradycardia; Official Journal Of The American Academy Of Pediatrics
11. Michael Miller; Christopher V. Maani; Labetalol; NCBI (2019)
12. How And When To Take Labetalol; NHS
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