Tuberculosis control is crucial to achieve the MDGs.

938 www.thelancet.com Vol 376 September 18, 2010 foods. Additional intervention studies, with better research designs that address individual, interpersonal, community, environmental, cultural, and policy determinants of gestational weight gain, are needed to identify eff ective clinical and population-based strategies to help women meet the guidelines about gestational weight gain. Ludwig and Currie do not have data for the eff ect of gestational weight gain on other child outcomes such as obesity. A study with data from the Avon Longitudinal Study of Parents and Children (ALSPAC) found that women who gained more weight than was recommended by the Institute of Medicine‘s guidelines had babies with greater adiposity, higher systolic blood pressure, C-reactive protein, interleukin 6, and leptin, and lower concentrations of HDL cholesterol and apolipoprotein A1 at 9 years of age. This study also found that maternal prepregnancy weight was more often associated with adiposity and cardiovascular risk factors in babies than was gestational weight gain, and that adjustment for birthweight did not substantially alter the associations of prepregnancy weight and gestational weight gain with these later child-health outcomes. The ALSPAC study shows the value of a prospective population-based birth cohort, above and beyond what can be learned from birth-certifi cate data. The recently launched National Children’s Study in the USA will further contribute to this emerging knowledge. A higher prepregnancy body-mass index and excessive gestational weight gain are most probably risk factors for increased birthweight, a range of perinatal complications, postnatal adiposity, and other metabolic changes associated with poor health outcomes, including childhood obesity. Although a better understanding of the eff ect of gestational weight gain on the developing fetus and metabolic functioning of the newborn child is important, research is urgently needed into how to help women of reproductive age attain and maintain a healthy weight before and during pregnancy. With a growing focus on preconceptional health, there is an opportunity to develop eff ective interventions to help women conceive at a healthier weight. More eff ective population-based strategies are needed to produce healthier life-long weight trajectories, and to interrupt the cross-generational cycle of excessive weight gain.