Key Takeaways
  • Melatonin levels tend to naturally increase with each trimester during pregnancy.
  • Research suggests that supplemental melatonin is safe during pregnancy when used under medical supervision.
  • Using the correct dosage is crucial for the safety and development of the pregnancy.

If you are pregnant, you might notice you have more trouble sleeping than usual. Research suggests that 46% to 78% of pregnant women experience sleep disorders. By the third trimester, nearly 80% of women experience insomnia. Naturally, many women experiencing these sleep problems seek out ways to manage them so they can improve their sleep quality.

Melatonin is a naturally occurring hormone produced by the brain that promotes sleep. Melatonin supplements are often marketed as sleep aids, so pregnant women with sleep problems might be curious about them as a potential remedy. Learn more about the research surrounding melatonin and pregnancy, as well as other useful strategies for improving sleep while pregnant.

The Role of Melatonin During Pregnancy

Naturally occurring melatonin appears to play a role in pregnancy, although more research is needed to fully understand how the hormone operates in this context. A pregnant woman’s melatonin can cross the placenta and bind to receptors in a fetus , suggesting melatonin levels impact an unborn baby. Additional melatonin may also be produced locally within the placenta. Melatonin levels in a placenta are highest during the first trimester. A pregnant woman’s melatonin levels increase after 24 weeks of pregnancy and again at 32 weeks .

Research suggests a woman’s melatonin levels may influence her ability to become and stay pregnant. One study found that night shift workers with disrupted melatonin levels are more likely to experience infertility and miscarriages . Melatonin promotes fertility by improving ovarian function and ovulation. Additionally, melatonin helps an embryo implant itself in the uterus and begin to grow.

Since melatonin levels tend to decrease with age, lower melatonin levels could be part of the reason older women are less fertile. Some researchers suggest that melatonin supplementation could help older women become pregnant.

Melatonin likely helps entrain a circadian rhythm in a fetus, which could potentially impact the baby’s sleeping patterns after birth. Melatonin may also affect neurological development in a fetus, reducing the likelihood of problems such as brain lesions.

Melatonin likely helps entrain a circadian rhythm in a fetus, which could potentially impact the baby's sleeping patterns after birth.

Melatonin levels are much lower in pregnant women experiencing severe preeclampsia. Preeclampsia is a condition in which a pregnant woman experiences high blood pressure, sometimes accompanied by excess protein in the urine . Left untreated, preeclampsia can lead to seizures or organ damage in pregnant women, as well as early birth or birth complications. Some professionals suggest melatonin supplements can help women with preeclampsia.

Is It Safe to Take Melatonin Supplements While Pregnant?

Currently, there is not enough research to confirm that taking melatonin supplements while pregnant is safe. Experts don’t recommend melatonin for insomnia, the sleep issue most commonly faced by pregnant women. Rather, melatonin has been found to usefully treat jet lag, delayed sleep-wake phase disorder, some sleep disorders in children, and anxiety before and after surgery.

In certain instances, however, healthcare professionals may recommend melatonin to pregnant women or women trying to become pregnant. For example, some professionals recommend melatonin supplements for older women trying to become pregnant and for pregnant women with preeclampsia. Studies suggest melatonin might also be useful for women with endometriosis .

In pregnant women without a documented health issue known to be associated with low melatonin levels, supplementation might not be a good idea. Melatonin levels naturally rise throughout pregnancy. One potential risk of supplementing with melatonin during this time could be too much melatonin in the body.

Melatonin levels naturally rise throughout pregnancy. One potential risk of supplementing with melatonin during this time could be too much melatonin in the body.

Researchers have not conducted much research on the safety of melatonin supplements in healthy pregnant women. In an animal study of pregnant rats, melatonin supplementation negatively impacted litter size, as well as the growth and mortality rates of the pups . However, we it is not clear if these results can be generalized to humans.

If you are pregnant and experiencing insomnia, melatonin supplementation may not be the best course of action. Instead, cognitive behavioral therapy for insomnia (CBT-I) and improved sleep hygiene might help. If you’re older and trying to get pregnant, or pregnant and facing preeclampsia, consult with your doctor before trying melatonin supplementation.

Asking Your Doctor About Melatonin and Sleep During Pregnancy

Talking to your doctor before taking melatonin or any supplement during pregnancy is of utmost importance. Your doctor will help ensure you aren’t exposing yourself to anything that could potentially harm you or your unborn baby. Additionally, your doctor can consider your health history and other medications and supplements to account for all potential problems and interactions.

If you’re curious about melatonin and sleep troubles during pregnancy, consider asking your doctor these questions:

  • What do you view as potential benefits and risks of supplementing with melatonin while pregnant?
  • Given my medical history and overall health, do you recommend I supplement with melatonin while pregnant?
  • Aside from supplementation, what strategies or treatments do you recommend for my current sleep troubles?

Finding Reputable Sleep Supplements

The safety and efficacy of supplements is not closely monitored by the U.S. Food and Drug Administration (FDA). Shoppers should take additional measures to make sure they are purchasing reputable products.

What Are Other Ways to Improve Sleep While Pregnant?

Many sleep tips exist to help you improve your sleep during pregnancy. A systematic review of multiple studies found limited evidence that the following interventions help  pregnant women sleep better :

  • Cognitive behavioral therapy for insomnia (CBT-I)
  • Pharmacotherapy
  • Acupuncture
  • Mindfulness and yoga
  • Relaxation
  • Herbal medication

Changing your sleep position could also help improve your sleep while you are pregnant. Side sleeping is generally recommended during pregnancy, and using blankets and pillows for support may make this position more comfortable.

Medical Disclaimer: The content on this page should not be taken as medical advice or used as a recommendation for any specific treatment or medication. Always consult your doctor before taking a new medication or changing your current treatment.

Learn more about our Editorial Team

9 Sources

  1. Smyka, M., Kosińska-Kaczyńska, K., Sochacki-Wójcicka, N., Zgliczyńska, M. & Wielgoś, M. (2020). Sleep problems in pregnancy—A cross-sectional study in over 7000 pregnant women in Poland. International Journal of Environmental Research and Public Health, 17(15), 5306.
  2. National Center for Complementary and Integrative Health. (2021, January). Melatonin: What you need to know., Retrieved May 26, 2021, from
  3. Olcese, J. M. (2020). Melatonin and female reproduction: An expanding universe. Frontiers in Endocrinology, 11, 85.
  4. Voiculescu, S. E., Zygouropouos, N., Zahiu, C. D., & Zagrean, A. M. (2014). Role of melatonin in embryo fetal development. Journal of Medicine and Life, 7(4), 488–492.
  5. Carlomagno, G., Minini, M., Tilotta, M., & Unfer, V. (2018). From implantation to birth: Insight into molecular melatonin functions. International Journal of Molecular Sciences, 19(9), 2802.
  6. Dulay, A. T. (2020, October). Preeclampsia and eclampsia. Merck Manual Consumer Version., Retrieved May 26, 2021, from
  7. Gustavo de Almeida Chuffa, L., Lupi, L. A., Smaniotto Cucielo, M., Spaulonci Silveira, H., Reiter, R. J., & Rodrigues Ferreira Seiva, F. (2019). Melatonin promotes uterine and placental health: Potential molecular mechanisms. International Journal of Molecular Sciences, 21(1), 300.
  8. Singh, H. J., Saleh, H. I., Gupalo, S., & Omar, E. (2013). Effect of melatonin supplementation on pregnancy outcome in Wistar-Kyoto and Sprague-Dawley rats. Sheng Li Xue Bao [Acta Physiologica Sinica], 65(2), 149–157.
  9. Bacaro, V., Benz, F., Pappaccogli, A., De Bartolo, P., Johann, A. F., Palagini, L., Lombardo, C., Feige, B., Riemann, D., & Baglioni, C. (2020). Interventions for sleep problems during pregnancy: A systematic review. Sleep Medicine Reviews, 50, 101234.

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