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Benzo Use in Pregnancy: Study Findings

Updated: Mar 23, 2023

Benzo use during pregnancy is a very difficult dilemma for pregnant women, especially for those who are already dependent. The decision of whether to stay on the drugs or taper during pregnancy is not without risks. There have been many warnings about complications with benzos during pregnancy, but a recent analysis has helped shine a light on a few of the concerns.

The Norwegian Mother and Child Cohort Study

A recent journal article regarding benzo use during pregnancy was just published by Simone N. Vigod, MD, MSc, FRCPC and Cindy-Lee Dennis, Phd, FCAHS in the Journal of the American Medical Association (JAMA). It was titled, “Benzodiazepines and the Z-Drugs in Pregnancy—Reasonably Reassuring for Neurodevelopment But Should We Really Be Using Them?”

In this study, Vigod and Dennis analyzed the results from the Norwegian Mother and Child Cohort Study which examined approximately 40,000 children born between 1999 and 2009. About 1% of the study, or 283 children, were exposed prenatally to benzodiazepines or Z-drugs. Various neurodevelopmental outcomes were assessed including fine motor, gross motor, and communication development. The results were a relief for many parents-to-be.

No differences were found between children exposed and unexposed to these medications [benzodiazepines and z-drugs] in association with the main outcomes. — Simone N. Vigod, MD, MSc, FRCPC and Cindy-Lee Dennis, Phd.

This is good news and will hopefully better inform the decision-making process during pregnancy.

Details and Caveats

As with all scientific studies, there are limitations and caveats. Here are a few which were mentioned in the analysis by Vigod and Dennis.

The study was limited by the self-reported nature of symptoms, a lack of dosage information, and a sample comprised solely of Norwegian women. It is important to acknowledge that the use of these medications is not completely benign (in pregnancy or otherwise). — Simone N. Vigod, MD, MSc, FRCPC and Cindy-Lee Dennis, Phd.

In the opening paragraph of the journal article, the authors also identified some concerns about benzo use during pregnancy.

Benzodiazepines and hypnotics, which act on the γ-aminobutyric acid–ergic neurotransmitter system, cross the placenta and the fetal blood-brain barrier, and could thus affect fetal brain development. The effect of fetal exposure to these medications—used on their own or often in combination with antidepressant drugs for anxiety or depression or opioids for pain—is largely unknown. — Simone N. Vigod, MD, MSc, FRCPC and Cindy-Lee Dennis, Phd

The truth is, as with all things benzos, there is still so much we don’t know. When I was writing Benzo Free, I researched this topic and wrote a couple of pages on it. I’d like to share a bit of that here.

Excerpt on Pregnancy from “Benzo Free”

Benzodiazepines taken during pregnancy cross the placental barrier and can affect the growth and development of the baby. These babies are more likely to be sick in the first few weeks of life and have their own withdrawal symptoms when they’re born since the supply of benzos has been cut off. This is known as neonatal abstinence syndrome. These symptoms can include breathing problems, sucking difficulties, poor body temperature control, and poor muscle tone — aka the “floppy infant syndrome.”

Also, benzodiazepines are excreted in breast milk. NYC Health Info states that benzodiazepines should be avoided during pregnancy because of the risk of adverse outcomes for the newborn.

It gets even more complicated for women who find themselves pregnant while already on a benzo long-term. Stopping cold turkey is not recommended, especially during pregnancy, but some say that a slow tapered withdrawal may be beneficial to the mother and newborn.

Sudden cessation of benzodiazepine use during pregnancy is potentially hazardous for both mother and foetus, including the risk of convulsions. Benzodiazepines may cause long-lasting and difficult-to-control withdrawal symptoms in the neonate, so any reduction in the level of use is to be encouraged. “Guidance for Prescribing and Withdrawal of Benzodiazepines & Hypnotics in General Practice,” NHS Grampian, October 2008

Dr. Kimberly Yonkers studied the effects of about 2,600 women during pregnancy and after childbirth. Her study showed some risk from benzodiazepines including an increase in C-sections, reduction in the duration of pregnancy, and some infants needing respiratory support after birth. Still, Yonkers cautioned by saying “it should be reassuring that we’re not seeing a huge magnitude of an effect here.” Similar effects were also found with some antidepressants (SSRIs) in this study.


Unfortunately, there are no easy answers here. Information is our greatest defense and I hope that I didn’t add stress or overwhelm anyone. While it appears that motor skill development may not be damaged by benzo use during pregnancy, other side effects may still be of concern.

Women who find themselves in this situation should work closely with their doctor and decide what course of action is best.

Keep calm, Taper Slowly, and Take Care of Yourself, D :)


  1. Ashton, C. Heather. Benzodiazepines: How They Work and How to Withdraw (aka The Ashton Manual). 2002. Accessed April 13, 2016.

  2. Aubrey, Allison. “Benefits Can Outweigh Risks for Pregnant Women on Anxiety Drugs or SSRIs.” NPR Shots. September 18, 2017. Accessed September 18, 2017.

  3. Foster, D E. Benzo Free: The World of Anti-Anxiety Drugs and the Reality of Withdrawal. Erie, Colorado: Denim Mountain Press, 2018.

  4. Haapanen, Laurell. “No Clinically Relevant ADHD Risk With Prenatal Benzodiazepine, Z-Hypnotic Exposure.” Psychiatry Advisor. April 5, 2019. Accessed April 6, 2019.

  5. Longo, Lance P. and Brian Johnson. “Addiction: Part I. Benzodiazepines — Side Effects, Abuse Risk and Alternatives.” American Family Physician 61(7)(April 1, 2000):2121-28. Accessed March 6, 2017.

  6. New South Wales Government (NSW). “Benzodiazepines.” Health Fact Sheets. Last updated July 11, 2013. Accessed March 6, 2017.

  7. New York City Department of Health and Mental Hygiene (NYC DOHMH). City Health Information: Judicious Prescribing of Benzodiazepines 35(2)(2016).

  8. U.K. National Health Service (NHS). “Guidance for Prescribing and Withdrawal of Benzodiazepines & Hypnotics in General Practice.” NHS Grampian. October 2006. Reviewed October 2008.

  9. Vigod, Simone N. and Cindy-Lee Dennis. “Benzodiazepines and the Z-Drugs in Pregnancy—Reasonably Reassuring for Neurodevelopment But Should We Really Be Using Them?” JAMA Netw Open. 2019;2(4):e191430. doi:10.1001/jamanetworkopen.2019.1430.


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