Limiting weight gain in overweight and obese women during pregnancy to improve health outcomes: the LIMIT randomised controlled trial

Extent: 5p.Background: Obesity is a significant global health problem, with the proportion of women entering pregnancy with a body mass index greater than or equal to 25 kg/m2 approaching 50%. Obesity during pregnancy is associated with a well-recognised increased risk of adverse health outcomes both for the woman and her infant, however there is more limited information available regarding effective interventions to improve health outcomes. The aims of this randomised controlled trial are to assess whether the implementation of a package of dietary and lifestyle advice to overweight and obese women during pregnancy to limit gestational weight gain is effective in improving maternal, fetal and infant health outcomes. Methods/Design: Design: Multicentred randomised, controlled trial. Inclusion Criteria: Women with a singleton, live gestation between 10+0-20+0 weeks who are obese or overweight (defined as body mass index greater than or equal to 25 kg/m2), at the first antenatal visit. Trial Entry & Randomisation: Eligible, consenting women will be randomised between 10+0 and 20+0 weeks gestation using a central telephone randomisation service, and randomisation schedule prepared by non-clinical research staff with balanced variable blocks. Stratification will be according to maternal BMI at trial entry, parity, and centre where planned to give birth. Treatment Schedules: Women randomised to the Dietary and Lifestyle Advice Group will receive a series of inputs from research assistants and research dietician to limit gestational weight gain, and will include a combination of dietary, exercise and behavioural strategies. Women randomised to the Standard Care Group will continue to receive their pregnancy care according to local hospital guidelines, which does not currently include routine provision of dietary, lifestyle and behavioural advice. Outcome assessors will be blinded to the allocated treatment group. Primary Study Outcome: infant large for gestational age (defined as infant birth weight ≥ 90th centile for gestational age). Sample Size: 2,180 women to detect a 30% reduction in large for gestational age infants from 14.40% (p = 0.05, 80% power, two-tailed). Discussion This is a protocol for a randomised trial. The findings will contribute to the development of evidence based clinical practice guidelines.Jodie M Dodd, Deborah A Turnbull, Andrew J McPhee, Gary Wittert, Caroline A Crowther and Jeffrey S Robinso

Antenatal interventions for overweight or obese pregnant women: a systematic review of randomised trials

Background Overweight and obesity during pregnancy is an increasing health problem. Objective A systematic review to assess the benefits and harms of antenatal dietary or lifestyle interventions for pregnant women who are overweight or obese. Search strategy The Cochrane Controlled Trials Register(CENTRAL) was searched (last search January 2010). Reference lists of retrieved studies were searched by hand. No date or language restrictions were used. Selection criteria Randomised controlled trials comparing antenatal dietary and/or lifestyle or other interventions with no treatment for overweight or obese women were considered. Studies were evaluated independently for appropriateness for inclusion and methodological quality. The primary outcome was large-for-gestational-age infants. Data collection and analysis Nine randomised controlled trials were included involving 743 women who were overweight or obese during pregnancy. Seven trials compared a dietary intervention with standard antenatal care. Main results There were no statistically significant differences identified between women who received an antenatal intervention and those who did not for the large-for-gestational-age infant outcome (three studies; 366 women; risk ratio 2.02; 95% CI 0.84, 4.86) or mean gestational weight gain [four studies; 416 women; weighted mean difference )3.10 kg; 95% CI )8.32, 2.13 (randomeffects model)]. There were no statistically significant differences identified for other reported outcomes. Author’s conclusions The effect of providing an antenatal dietary intervention for overweight or obese pregnant women on maternal and infant health outcomes remains unclear.JM Dodd, RM Grivell, CA Crowther, JS Robinso