Lifestyle advice, including diet and exercise information, for pregnant women who were overweight or obese, did not reduce the risk of their infants being born large for gestational age or improve maternal outcomes, new research revealed.
The randomized study of 2,152 pregnant women, however, found that lifestyle advice did lead to a significant reduction in the number of babies born weighing more than 4 kg (8.8 lb).
- Lifestyle advice, including diet and exercise information, did not reduce the risk of obese or overweight women delivering large-for-gestational-age infants.
- The advice, provided by a dietitian and research staff, also did not improve maternal outcomes.
- Lifestyle advice was, however, associated with a reduction in the number of infants born weighing more than 4 kg (8.8 lb).
Half the women received lifestyle advice (n=1075), which included dietary, exercise, and behavioral strategies delivered by a research dietician and trained research assistants. The other half received standard care (n=1067). The findings showed that of the women in the lifestyle group, 164 (15%) women had infants with a birth weight of greater than 8.8 lb, compared with 201 (19%) women in the control group (adjusted relative risk, 0.82; 95% confidence interval, 0.68 to 0.99; number needed to treat, 28 [15 to 263]; P=0.04).
"We know that babies who are born over 4 kg have a two-fold increased risk of being overweight or obese as children, which often carries into later life, bringing with it a range of health concerns, such as cardiovascular disease and diabetes,” said Jodie Dodd, MD, PhD, professor of obstetrics and gynecology, the University of Adelaide's Robinson Institute and the Women's and Children's Hospital. “So we're pleased to see that the study has led to a significant reduction in the risk of a baby being born over 4 kg.”
The study findings did show, however, that the risk of the infant being large for gestational age was not significantly different between the two groups (lifestyle advice 203/1075 [19%] vs standard care 224/1067 [21%]; adjusted relative risk 0.90; 95% confidence interval, 0.77 to 1.07; P=0.24). There were also no differences in maternal pregnancy outcomes between groups, including the amount of maternal weight gain. In addition, there were no differences in birth outcomes.
"Our focus was on providing simple, practical lifestyle advice that is very achievable in the real world,” Dodd said. “It wasn't about going on a diet, but focused on healthy eating and increasing activity levels on a daily basis.”
Compliance among the lifestyle group was a limitation—not all women attended scheduled appointments with the dietitian. Only 87% went to the first appointment, and 77% attended the second session. Furthermore, the study struggled to recruit willing participants, with 60% of eligible women declining to be enrolled. The authors said the difficulty in identifying willing participants reflected a lack of interest and a lack of time.
Dodd JM, Turnbull D, McPhee AJ, et al. Antenatal lifestyle advice for women who are overweight or obese: LIMIT randomized trial. BMJ. 2014;348:g1285.