Peripartum outcomes after combined myo-inositol, probiotics, and micronutrient supplementation from preconception: the NiPPeR randomized controlled trial

Evidence that nutritional supplementation before and during pregnancy improves peripartum outcomes is sparse. In the Nutritional Intervention Preconception and During Pregnancy to Maintain Healthy Glucose Metabolism and Offspring Health (NiPPeR) trial, we previously reported that a combined myo-inositol, probiotics, and micronutrient supplement started at preconception showed no difference in the primary outcome of gestational glycemia, but did reduce the risk of preterm delivery, preterm prelabor rupture of membranes, and major postpartum hemorrhage. This study aimed to examine the hypothesis that a reduction in major postpartum hemorrhage following a combined nutritional (myo-inositol, probiotics, and micronutrients) intervention is linked with promotion of labor progress and reduced operative delivery. This double-blind randomized controlled trial recruited 1729 women from the United Kingdom, Singapore, and New Zealand, aged 18 to 38 years, and planning conception between 2015 and 2017. The effects of the nutritional intervention compared with those of a standard micronutrient supplement (control), taken at preconception and throughout pregnancy, were examined for the secondary outcomes of peripartum events using multinomial, Poisson, and linear regression adjusting for site, ethnicity, and important covariates. Of the women who conceived and progressed beyond 24 weeks’ gestation with a singleton pregnancy (n=589), 583 (99%) provided peripartum data. Between women in the intervention (n=293) and control (n=290) groups, there were no differences in rates of labor induction, oxytocin augmentation during labor, instrumental delivery, perineal trauma, and intrapartum cesarean delivery. Although duration of the first stage of labor was similar, the second-stage duration was 20% shorter in the intervention than in the control group (adjusted mean difference, −12.0 [95% confidence interval, −22.2 to −1.2] minutes; P=.029), accompanied by a reduction in operative delivery for delayed second-stage progress (adjusted risk ratio, 0.61 [0.48–0.95]; P=.022). Estimated blood loss was 10% lower in the intervention than in the control group (adjusted mean difference, −35.0 [−70.0 to −3.5] mL; P=.047), consistent with previous findings of reduced postpartum hemorrhage. Supplementation with a specific combination of myo-inositol, probiotics, and micronutrients started at preconception and continued in pregnancy reduced the duration of the second stage of labor, the risk