The effect of antenatal lifestyle advice for women who are overweight or obese on secondary measures of neonatal body composition: the LIMIT randomised trial.

OBJECTIVE: To evaluate the effect of providing antenatal dietary and lifestyle advice on neonatal anthropometry, and to determine the inter-observer variability in obtaining anthropometric measurements. DESIGN: Randomised controlled trial. SETTING: Public maternity hospitals across metropolitan Adelaide, South Australia. POPULATION: Pregnant women with a singleton gestation between 10(+0) and 20(+0) weeks, and body mass index (BMI) ≥25 kg/m(2). METHODS: Women were randomised to either Lifestyle Advice (comprehensive dietary and lifestyle intervention over the course of pregnancy including dietary, exercise and behavioural strategies, delivered by a research dietician and research assistants) or continued Standard Care. Analyses were conducted using intention-to-treat principles. MAIN OUTCOME MEASURES: Secondary outcome measures for the trial included assessment of infant body composition using body circumference and skinfold thickness measurements (SFTM), percentage body fat, and bio-impedance analysis of fat-free mass. RESULTS: Anthropometric measurements were obtained from 970 neonates (488 Lifestyle Advice Group, and 482 Standard Care Group). In 394 of these neonates (215 Lifestyle Advice Group, and 179 Standard Care Group) bio-impedance analysis was also obtained. There were no statistically significant differences identified between those neonates born to women receiving Lifestyle Advice and those receiving Standard Care, in terms of body circumference measures, SFTM, percentage body fat, fat mass, or fat-free mass. The intra-class correlation coefficient for SFTM was moderate to excellent (0.55-0.88). CONCLUSIONS: Among neonates born to women who are overweight or obese, anthropometric measures of body composition were not modified by an antenatal dietary and lifestyle intervention.

Systematic review of antenatal dietary and lifestyle interventions in women with a normal body mass index.

INTRODUCTION: Women who commence pregnancy with a normal body mass index (BMI) are at the greatest risk of excessive gestational weight gain, impacting on infant birthweight, pregnancy-related complications and postpartum weight retention. Our aim was to review systematically the effect of antenatal dietary and lifestyle interventions in pregnant women with a normal BMI on maternal and infant outcomes. MATERIAL AND METHODS: We searched the Cochrane Controlled Trials Register, PubMed, Medline, and the Australian and International Clinical Trials Registry with the date of the last search in July 2015. We included all published, unpublished and ongoing randomized trials recruiting women of a normal BMI, comparing dietary and/or lifestyle interventions with standard antenatal care. RESULTS: Twelve randomized controlled trials were identified, involving a total of 2713 pregnant women, with five studies reporting clinical data for 714 women with a normal BMI. Women who received a dietary and lifestyle intervention were less likely to experience gestational weight gain [four studies, 446 women; mean difference -1.25 kg; 95% confidence interval (CI) -2.39 to -0.11], weight gain above the Institute of Medicine guidelines (four studies, 446 women; risk ratio 0.66; 95% CI 0.53-0.83) and hypertension (two studies; 243 women; risk ratio 0.34; 95% CI 0.13-0.91). There were no statistically significant differences in the occurrence of gestational diabetes, cesarean section or birthweight greater than 4 kg. CONCLUSIONS: While providing an antenatal dietary and lifestyle intervention for pregnant women of normal BMI appears to reduce gestational weight gain, the review was limited by the relatively small available sample size. Further well-designed randomized controlled trials are required.