Evaluation of Exercise to Manage Gestational Diabetes in Obese Mothers
Researchers at the UCD Centre for Human Reproduction have evaluated the use of a medically supervised pregnancy exercise intervention in obese women as a strategy to improve maternal glycemia and gestational weight gain.
Maternal obesity has emerged as one of the greatest challenges in modern obstetrics. Approximately half of women of reproductive age are either overweight (body mass index of 25.0 or greater) or obese. Maternal obesity has been linked with adverse pregnancy outcomes, including gestational diabetes mellitus (GDM). Increasing severity of maternal obesity leads to a higher risk of GDM with a two-, four-, and eightfold risk of GDM for overweight, obese, and severely obese women, respectively.
With growing obesity internationally and escalating GDM rates, effective preventive strategies are required to avoid the adverse outcomes associated with obesity and hyperglycemia during pregnancy. Outside pregnancy, lifestyle interventions have reduced the incidence of subsequent type 2 diabetes mellitus. Pregnancy often results in a reduction in exercise and physical activity levels with obese women exercising least before and during pregnancy.
The study was conducted at the Coombe Women’s & Infants University Hospital by Dr Niamh Daly and colleagues at the UCD Centre for Human Reproduction. The randomized control trial, published in the US journal, Obstetrics and Gynaecology, compared a medically supervised exercise intervention with routine prenatal care.
The evaluated intervention consisted of 50–60 minutes of exercise comprising warm-up, resistance or weights, aerobic exercises, and cool-down. All women received routine prenatal care.
88 women were randomized: 44 each to the exercise and control groups. Eight women in the control group and 11 in the intervention group did not complete the trial at 6 weeks postpartum (P5.61), but 43 in each group attended the 24- to 28-week glucose screen. There were no baseline maternal differences between groups. Classes commenced at a mean of 13 4/761 2/7 weeks of gestation. In early pregnancy, 51.1% (n545/88) had an elevated fasting plasma glucose (92–125 mg/dL). There was no difference in the mean fasting plasma glucose at 24–28 weeks of gestation: 90.069.0 mg/dL (n543) compared with 93.667.2 mg/dL (n543) (P5.13) or in the incidence of gestational diabetes mellitus at 24–28 weeks of gestation: 48.8% (n521/43) compared with 58.1% (n525/43) (P5.51) in the control and exercise groups, respectively. At 36 weeks of gestation, excessive gestational weight gain greater than 9.1 kg was lower in the exercise group, 23.5% compared with 45.2% in the control group (P,.05).
The primary outcome was a reduction in mean maternal fasting plasma glucose in the intervention group by 6.9 mg/dL at the time of a 75-g oral glucose tolerance test at 24–28 weeks of gestation. The secondary outcomes investigated the effects of the exercise intervention on longitudinal fasting plasma glucose concentrations and the incidence of GDM at the time of the OGTT at 24–28 weeks of gestation; birth outcomes: induction of labor, mode of delivery and length of labor, birth weight, birth weight centile less than 10th and greater than 90th centiles, gestational age at delivery, preterm births, admission to neonatal intensive care unit, abnormal Apgar scores less than 7 at 1 and 5 minutes; and gestational weight gain: mean gestational weight gain at 24–28 and 36 weeks of gestation, excessive gestational weight gain greater than 9.1 kg at 36 weeks of gestation, and mean postpartum weight retention at 6 weeks postpartum.
The study showed that an intensive, medically supervised exercise intervention for obese women from early pregnancy did not improve maternal glycemia. Pregnant women who are obese, however, should be advised to exercise because it attenuates excessive gestational weight gain.
The study was partly funded by Friends of the Coombe Charity and the study results were presented at the Society for Maternal-Fetal Medicine’s 37th Annual Pregnancy Meeting, January 23–28, 2017, Las Vegas, Nevada.
A Medically Supervised Pregnancy Exercise Intervention in Obese Women | A Randomized Controlled Trial. Niamh Daly, Maria Farren, Aoife McKeating, Ruth O’Kelly, Mary Stapleton, and Michael J. Turner, Obstet Gynecol. 2017 Nov;130(5):1001-1010 [link]