The Impact of an Early Lifestyle Intervention on Pregnancy Outcomes in a Cohort of Insulin-Resistant Overweight and Obese Women

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.

Association of Improved Periconception Hemoglobin A1c With Pregnancy Outcomes in Women With Diabetes

“…Among women with insulin resistance who are overweight or obese, a recent Italian randomized clinical trial (RCT) found that a lifestyle intervention beginning at 9 to 12 weeks’ gestation improved neonatal outcomes. 24 Ongoing HbA 1c control in the third trimester of pregnancy is also associated with a lower risk of perinatal mortality. 6 An additional clinically relevant finding is affirmation of the recommended periconceptional HbA 1c of less than 6.5%.…”

A First Trimester Prediction Model for Large for Gestational Age Infants: A Preliminary Study

“…Moreover, also interpregnancy weight increase has found to be associated with LGA 33 . Therefore, we and others previously demonstrated that implementing an early customized low glycemic index, low fat diet together with the stimulation of physical activity has the potential to reduce the risk of LGA baby in some populations 34,35 . Unfortunately, quality, timing and adherence to intervention are factors signi cantly affecting success 42 .…”

The Role of Diet on Insulin Sensitivity

“…One-on-one dietary counseling and an on-demand support system delivered by primary care personnel, even if coupled with limited adherence to physical activity and only modest weight loss after 6 months of lifestyle intervention, were more effective than standard care in improving glycaemic and cardiometabolic profiles in this target group [ 12 ]. The beneficial effects of an intensive lifestyle intervention, starting in early pregnancy and made of a calorie-restricted, low-glycemic-index, low-saturated-fat diet combined with moderate intensity physical activity (30 min of walking at least four days a week) were evaluated by Menichini and colleagues [ 14 ]. In obese singleton pregnant women with IR, this early intensive lifestyle intervention did not reduce the incidence rate of GDM with respect to standard care; however, mean glucose values at 75 g oral glucose tolerance test (OGTT), performed at 16–18 and/or 24–28 weeks of gestation in agreement with Italian guidelines, were significantly lower, as well as the birth rate of large-for-gestational-age (LGA) babies [ 14 ].…”

“…The beneficial effects of an intensive lifestyle intervention, starting in early pregnancy and made of a calorie-restricted, low-glycemic-index, low-saturated-fat diet combined with moderate intensity physical activity (30 min of walking at least four days a week) were evaluated by Menichini and colleagues [ 14 ]. In obese singleton pregnant women with IR, this early intensive lifestyle intervention did not reduce the incidence rate of GDM with respect to standard care; however, mean glucose values at 75 g oral glucose tolerance test (OGTT), performed at 16–18 and/or 24–28 weeks of gestation in agreement with Italian guidelines, were significantly lower, as well as the birth rate of large-for-gestational-age (LGA) babies [ 14 ]. There is evidence that an excessive shunting of maternal nutrients across the placenta accelerates fetal growth and adipose tissue accretion from the early stages of pregnancy, and this increases the risk of macrosomia [ 15 ].…”

“…At the same time, fetal growth restriction due to maternal undernutrition during pregnancy may end up in small-for-gestational-age (SGA) births, negatively affecting the perinatal morbidity and mortality, as well as the longer-term health, of newborns [ 16 ]. Still, in obese women with IR, repeatedly identified at higher risk for GDM complications when compared to their normal weight counterparts [ 15 ], the early lifestyle intervention with moderate reduction in caloric intake presented by Menichini and colleagues did not increase the risk of giving birth to SGA babies [ 14 ]. A different shade of evidence for the insulin-sensitizing effects of a low glycemic index diet was added by the work of Gao and colleagues [ 17 ].…”