There are several strengths in our study, including the use of GWG category instead of net weight gain, and the repeated direct measures of the growth and development of infants at birth and each 3 months until 1 year old. A limitation of our study is that we only followed infant growth to 12 months old. Thus we cannot assess the effect of maternal weight gain during pregnancy on offspring’s growth and development after 12 months old. However, the present study is an ongoing project, and we will get the children’s later growth and development information in the near future.