No abstract

Obese women are more likely to have decreased insulin sensitivity and are at increased risk for many adverse pregnancy outcomes. An early lifestyle intervention (LI) may have the potential to reduce the impact of insulin resistance (IR) on perinatal outcomes. We report post hoc analysis of an open-label randomized control trial that includes IR women with body-mass index ≥25 randomly assigned to a LI with a customized low glycemic index diet or to standard care (SC) involving generic counseling about healthy diet and physical activity. Women were evaluated at 16, 20, 28, and 36 weeks of gestation, at which times perinatal outcomes were collected and analyzed. An oral-glucose-tolerance test (OGTT) showed that women in the LI group had lower plasma glucose levels at 120 min at 16–18 weeks of gestation, and at 60 and 120 min at 24–28 weeks. More importantly, these women had a lower rate of large-for-gestational-age (LGA) infants (p = 0.04). Interestingly, the caloric restriction and low-glycemic index diet did not increase the rate of small-for-gestational-age (SGA) babies in the LI group. A lifestyle intervention started early in pregnancy on overweight and obese women had the potential to restore adequate glucose tolerance and mitigate the detrimental role of IR on neonatal outcomes, especially on fetal growth.

Abstract. Vitamin D is a secosteroid hormone that plays a pivotal role in several metabolic and reproductive pathways in humans. Increasing evidence supports the role of vitamin D deficiency in metabolic disturbances and infertility in women with polycystic ovary syndrome (PCOS). Indeed, supplementation with vitamin D seems to have a beneficial role on insulin resistance and endometrial receptivity. On the other hand, exceedingly high levels of vitamin D appear to play a detrimental role on oocytes development and embryo quality. In the current review, we summarize the available evidence about the topic, aiming to suggest the best supplementation strategy in women with PCOS or, more generally, in those with metabolic disturbances and infertility. Based on the retrieved data, vitamin D seems to have a beneficial role on IR, insulin sensitivity and endometrial receptivity, but high levels and incorrect timing of administration seem to have a detrimental role on oocytes development and embryo quality. Therefore, we encourage a low dose supplementation (400–800 IU/day) particularly in vitamin D deficient women that present metabolic disturbances like PCOS. As far as the reproductive health, we advise vitamin D supplementation in selected populations, only during specific moments of the ovarian cycle, to support the luteal phase. However, ambiguities about dosage and timing of the supplementation still emerge from the clinical studies published to date and further studies are required.