Pregnant females often have difficulty sleeping, with consequences including fatigue and an increased risk of labor and delivery complications. Treatment options (that are also safe for the fetus) are few. Myo-inositol, a carboxylic sugar found in the brain and other tissues, is given during pregnancy to improve glucose metabolism, but it may also regulate vital functions related to sleep.

The study

In this 10-week randomized controlled trial, 56 females at 14 weeks of gestation took either 2 grams of myo-inositol (with 200 μg of folic acid) or a placebo (200 μg of folic acid). The primary outcome was a change in sleep quality from baseline (first trimester) to study end (second trimester), as measured by validated scales. The secondary outcomes included notably maternal and neonatal health at birth.

The results

Immediately after the intervention, overall sleep-quality scores improved in the myo-inositol group but not the control group. Specifically, the myo-inositol group reported better subjective sleep quality, sleep duration, and sleep efficiency (the percentage of time spent asleep while in bed). Three months after the intervention, there were no longer any significant differences in sleep quality between the two groups, who didn’t differ in maternal and neonatal outcomes either.


Although the abstract states that the control group took 400 μg of folic acid, the article itself states that they “received placebo containing 200 μg of folic acid”. Since it makes little sense to add a confounder to the experiment by using a placebo that has twice as much folic acid as the supplement, the “200 μg” is most probably correct.

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This Study Summary was published on November 5, 2020.