Testing Effects of Melatonin on Uterine Contractions in Women

Study Overview
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Brief Summary
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The study will extend recent discoveries that have been made in basic human physiology related to responses melatonin and uterine contractions in late- or full-term pregnant women. The basic physiology work has been conducted in in vitro models of the human myometrium characterizing its responses to melatonin, and in pilot in vivo studies correlating the number of uterine contractions with melatonin concentrations that were manipulated by different types of light exposure. The planned experiments will test a causal link between circulating melatonin levels and uterine contractions in full-term pregnant women by manipulating melatonin levels using exogenous melatonin (i) during the day when endogenous levels of melatonin are very low (Experiment 1), and (ii) during the evening under conditions with lighting that would be expected to suppress the higher evening and nighttime levels of endogenous melatonin (Experiment 2).

Official Title
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Testing Effects of Melatonin on Uterine Contractions in Women

Conditions
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Pregnant Women

Intervention / Treatment
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* Dietary Supplement: Melatonin
* Dietary Supplement: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: nulliparity, age between 18 and 35, BMI<36 pre-pregnancy, ≥40 weeks of pregnancy with a single fetus at time of study. pregnancy-associated obstetrical care by nurse midwife or physician associated with MassGeneralBrigham (MGB) (including hospital and community health centers) planned admission for delivery at a MGB affiliated institution. Exclusion Criteria: color blind; prescription drugs affecting sleep, melatonin, and/or circadian rhythms (e.g., beta blockers, non-steroidal anti-inflammatory drugs); a health or pregnancy related condition that might affect melatonin or uterine contractions; medical conditions or medications for which melatonin might be contraindicated or there may be a drug interactions (e.g., Central Nervous System depressants/sedatives, Fluvoxamin (Luvox), medications for diabetes, immunosuppressants, anti-coagulants, Nifedipine, Verapamil). Note: We cannot list all possible exclusionary criteria. Dr. Carolina Bibbo (co-I), our Obstetrics Investigator at Brigham and Women's Hospital (BWH), will make final determination of suitability including any safety concerns for each potential participant.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 35 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Daytime melatonin 0.0 mg<br> | Dietary Supplement: Placebo<br>* Oral placebo administered as a single pill.<br>|
| Experimental: Daytime melatonin 0.5 mg<br> | Dietary Supplement: Melatonin<br>* Oral melatonin administered as a single pill.<br>|
| Experimental: Daytime melatonin 3.0 mg<br> | Dietary Supplement: Melatonin<br>* Oral melatonin administered as a single pill.<br>|
| Placebo Comparator: Nighttime melatonin 0.0 mg<br> | Dietary Supplement: Placebo<br>* Oral placebo administered as a single pill.<br>|
| Experimental: Nighttime melatonin 0.5 mg<br> | Dietary Supplement: Melatonin<br>* Oral melatonin administered as a single pill.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Daytime: Total number of uterine contractions | Daytime: Total number of uterine contractions | 10 hours | 
| Nighttime: Total number of uterine contractions | Nighttime: Total number of uterine contractions | 4 hours |