Effects of an antenatal lifestyle intervention on offspring obesity - a 5-year follow-up of a randomized controlled trial.

INTRODUCTION: Strategies to limit excessive maternal gestational weight gain could also have positive health effects for the offspring. This study informs us on the effect of an antenatal lifestyle intervention on offspring body mass index (BMI) trajectory until age five.

MATERIAL AND METHODS: A secondary analysis of a randomized controlled trial aimed at reducing gestational weight gain, set in Ørebro, Sweden (Clinical Trials.gov Id NCT00451425). Offspring were followed with standardized measures of weight and height until age five. Mean BMI z-score and proportion (%) of over- and undernutrition (BMI z-score > ± 2 standard deviations) was compared between groups. Risk estimates for obesity at age five were analyzed in relation to maternal gestational weight gain and prepregnancy BMI as a secondary outcome.

RESULTS: We analyzed 374 children at birth and 300 at age five. No significant difference in mean BMI z-score was seen at birth (0.68 (I) vs 0.56 (C), p = 0.242) or at age five (0.34 (I) vs 0.26 (C), p = 0.510) and no significant difference in proportion of over- or undernutrition was seen. Excessive maternal gestational weight gain was an independent risk factor for offspring obesity at birth (OR = 4.51, p < 0.001) but not at age five. Maternal obesity was an independent risk factor for offspring obesity at age five (OR = 4.81, p = 0.006).

CONCLUSIONS: Our composite antenatal lifestyle intervention did not significantly reduce the risk of obesity in offspring up until age five.