From the Guidelines
Melatonin should be avoided during pregnancy unless absolutely necessary and under the guidance of a healthcare provider. The safety of melatonin during pregnancy is not fully established, and there is limited research on how exogenous melatonin might affect fetal development, placental function, or pregnancy outcomes 1. While melatonin is a natural hormone produced by the body to regulate sleep cycles, supplemental forms have not been adequately studied in pregnant women.
Some key points to consider when evaluating the use of melatonin in pregnancy include:
- Melatonin does cross the placenta and could potentially influence fetal circadian rhythms and development 1.
- The study from the Journal of Clinical Sleep Medicine in 2008 notes that sedatives/hypnotics, including melatonin receptor agonists, are not recommended during pregnancy or nursing 1.
- General comments about sedatives/hypnotics advise caution if signs/symptoms of depression, compromised respiratory function, or hepatic heart failure are present, which may be relevant for pregnant women with pre-existing conditions 1.
For sleep difficulties during pregnancy, safer approaches include:
- Practicing good sleep hygiene (maintaining a regular sleep schedule, creating a comfortable sleep environment, avoiding screens before bedtime).
- Using pregnancy pillows for comfort.
- Trying relaxation techniques such as gentle yoga or meditation. If sleep problems are severe, it's essential to consult with an obstetrician who can recommend pregnancy-safe interventions and weigh the potential risks and benefits of melatonin use in individual cases where sleep disturbances are significantly impacting maternal health.
From the Research
Melatonin Safety in Pregnancy
- The use of exogenous melatonin during pregnancy is quite common, with a prevalence of around 4% in pregnant populations 2.
- Clinical trials that used exogenous melatonin during pregnancy have not suggested major safety concerns or adverse events, contrary to what animal studies have suggested 2.
- Evidence from clinical studies to date suggests that melatonin use during pregnancy is probably safe in humans 2.
- However, there is a lack of randomized, controlled trials examining the efficacy and safety of melatonin as a treatment for sleep disorders during pregnancy 2.
- Melatonin has been shown to synchronize the circadian rhythms, and improve the onset, duration and quality of sleep, with no obvious short- or long-term adverse effects 3.
Comparison with Other Sleep Disorder Treatments
- Other medications used to treat insomnia during pregnancy, such as benzodiazepines, sedative-hypnotics, antihistamines, and trazodone, have potential risks and side effects 4.
- Melatonin offers an alternative treatment to these pharmaceutical therapies for sleep disorders with significantly less side effects 3.
- Cognitive-behavioral therapy for insomnia is also an effective treatment for perinatal insomnia, which is associated with depression and anxiety 5.
Need for Further Research
- More research is needed to establish the safety and efficacy of melatonin use during pregnancy, particularly in the context of sleep disorders 2, 4.
- Future studies should aim to characterize the associations between melatonin use and pregnancy outcomes, and to inform the design of adequately powered randomized controlled trials testing the impact of melatonin on cardiovascular health during pregnancy 6.