In this issue of JAMA, van der Wel et al present their findings from a randomized clinical trial to assess whether myo-inositol, a nutritional supplement, lowers the incidence of a composite outcome of pregnancy complications (including gestational diabetes, preeclampsia, and preterm birth), compared with placebo, among 464 individuals with polycystic ovary syndrome (PCOS). Supplementation with myo-inositol has been shown to improve insulin sensitivity and improve conception rates among individuals with PCOS. However, prior to this study, evidence to support the use of myo-inositol to improve pregnancy outcomes in this population was lacking.