Objective  To examine the distribution of anogenital distance (AGD) among children aged 0 – 4 years in Shanghai city and to explore the influence of body weight and length/height on AGD.

  Methods  The study was conducted among the participants of a birth cohort established in Shanghai city by Minhang District Maternal and Child Health Hospital (S-MBCS) from April to December, 2012. The delivery information were collected among 1 157 newborns and the AGD and birth weight of the newborns were measured. The newborns were followed up and their AGD and body weight were measured at 6, 12, and 48 months of age.

  Results  For all the newborns, the AGD values of the boys were greater than those of the girls for the measurements at the birth and the ages of 6, 12, and 48 months old. Among the newborns, the increment of AGD from the birth till the age of 6 months were greater than that from the age of 6 months to 12 months. The results of multivariate linear regression demonstrated that the AGD was positively correlated with birth weight among both the boys and the girls, with following significant regression coefficients: β = 3.56 (95% confidence interval 95% CI: 2.52 – 4.61) for AGD_AP of boys (from the anus to the cephalad insertion of the penis), β = 1.30 (95% CI: 0.40 – 2.21) for AGD_AS of boys (from the anus to the posterior base of the scrotum), β = 2.77 (95% CI: 1.90 – 3.63) for AGD_AC of the girls (from the anus to the clitoris), and β = 1.23 (95% CI: 0.55 – 1.91) for AGD_AF of girls (from the anus to the posterior convergence of the fourchette), respectively. The AGD was associated with body weight but not with body length/height for all the newborns at their ages of 6, 12, and 48 months.

  Conclusion  The study reported distributions of AGD among children in Shanghai city longitudinally from their birth to the age of 4 years. The study results confirm gender difference in AGD and birth weight correlates with AGD among the children.