Ingredient guide · Ingredient reference

Myo-inositol in PCOS pregnancy: a large trial was negative

The trial did not reduce its combined endpoint of gestational diabetes, preeclampsia or preterm birth.

Read the evidence ↓

Supplement Science Insights Editorial Team

Published September 23, 2026

The study and its comparison

A Dutch multicenter trial randomized 464 pregnant participants with PCOS at 8–16 weeks of gestation. Both groups received folic acid; the intervention added myo-inositol 2 grams twice daily until delivery. [1]

The primary composite occurred in 25.0 percent of the inositol group and 26.8 percent of controls. The relative risk was 0.93, with a confidence interval spanning benefit and harm. [1]

What the finding establishes

The masked comparison does not support claiming prevention of these complications in this population. It did not test conception rates or every inositol ratio. Baseline biochemical hyperandrogenism differed between groups. Authors disclosed several pharmaceutical relationships; trial funding was not established from the retrieved record. [1]

A hypothetical distinction

Imagine a supplement has been discussed for fertility. A pregnancy-complication trial answers a different question.

Interpretation checklist — Myo-inositol in PCOS pregnancy
DetailInterpretation
Measured outcomeKeep the endpoint specific
Study preparationNot every retail product
Remaining uncertaintyNot resolved by a mechanism
Myo-inositol in PCOS pregnancy: a large trial was negative — original article outline diagram
Original editorial diagram of this article’s sections; no product photograph or clinical finding is depicted.

Sources for this article

  1. Myo-inositol Supplementation to Prevent Pregnancy Complications in Polycystic Ovary Syndrome: A Randomized Clinical Trial.
    Source consulted: 2026-09-19. This is a reference resource, not a claim that we conducted the studies or tested a product.