Montelukast During Pregnancy

Using Montelukast During Pregnancy: Side Effects and Risks

Asthma is a challenging breathing condition experienced by many Americans. Unfortunately, it is usually a chronic condition that creates ongoing challenges and management questions for individuals experiencing this condition.

Now that you have discovered you are pregnant, asking questions about using montelukast during your pregnancy to help manage your asthma is atop your mind. Montelukast, more commonly known as Singulair, use during pregnancy is probably alright for your developing baby.

Below is information on Singulair use during pregnancy that you can review and use to help you have a more insightful discussion with your health care provider.

It is always important to discuss any health concerns and medication use during pregnancy with your health care provider. Your health care provider wants the best for both you and your developing baby.

Brand name: Singulair Manufacturer: Merck & Co

Therapeutic Effect: Singulair is indicated for the prophylaxis and chronic treatment of asthma in adults and pediatric patients 12 months of age and older. Singulair is also indicated for prevention or exercise-induced bronchoconstriction in patients 15 years of age and older and for the relief of symptoms of seasonal allergic rhinitis in patients 2 years of age and older and perennial allergic rhinitis in patients 6 months of age and older.

Pregnancy Safety Rating: Category: B

Pregnancy Recommendation: Limited human data-Probably compatible

Side Effects:

Adults, children 15 yrs and older

Lifespan Considerations

  • Pregnancy/Lactation: Unknown if distributed in breast milk. Use during pregnancy only if necessary. Pregnancy Category B

Pregnancy Summaries for Montelukast During Pregnancy

Briggs, Freeman, & Yaffe – Montelukast is not teratogenic in animals, and few adverse outcomes in humans do not demonstrate a pattern that suggests a common etiology. One source states that montelukast may be safe to use during pregnancy, but this conclusion was based solely on animal studies (1). A 2000 position statement of the American College of Obstetricians and Gynecologists and the American College of Allergy, Asthma and Immunology recommended that montelukast could be considered in patients with recalcitrant asthma who had shown a uniquely favorable response to the drug prior to becoming pregnant(2).

The available data supports this assessment. The manufacturer maintains a pregnancy registry for women exposed to montelukast. Health care professionals are encouraged to report pregnancy exposures to the registry by calling the toll free number 800-986-8999.

Physicians’ Desk Reference – There are no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, Singulair should be used during pregnancy only if clearly needed. For further information, please refer to the Physicians’ Desk Reference or contact your Healthcare Provider.

Reprotox Toxicology Center – Based on experimental animal data, montelukast is not expected to increase the risk of congenital anomalies. A registry including 203 exposed pregnancies has not identified a syndrome of abnormalities associated with montelukast exposure.

Limb reduction defects are now mentioned in the warning label for this drug, because 6 cases have been collected in international reports. Available data do not establish a causative link between the drug and this class of congenital defects.

If you are pregnant and have questions related to medication use during pregnancy, the Reprotox Toxicology Center is the most comprehensive and easiest to use resource on medication use during pregnancy.  You can subscribe for only $17.00 – Subscribe Now.

The American Pregnancy Association does not prescribe medication nor do we serve as a consult for medication use during pregnancy.  It is imperative that you discuss the use of any medication during pregnancy with your health care provider.

The purpose of this document is to provide you with information to support discussions with your health care provider.


  1. Hudgson, Barbara and Kizior, Robert, Saunders Nursing Drug Handbook 2012, Elsevier, St. Louis, MO. ISBN: 978-1-4377-2334-2.
  2. Briggs, Gerald, Freeman, Roger and Yaffe, Sumner, Drugs in Pregnancy and Lactation, 9th Ed., Wolters Kluwer/Lippincott Williams & 3. Wilkins, Philadelphia, PA. ISBN: 978-1-60831-708-0, 2011.
  3. Physicians’ Desk Reference (PDR), PDR Network, LLC, Motvale, NJ 07645 ISBN: 978-1-56363-780-3
  4. Reproductive Toxicology Center,, agent # 4087