Bouckaert A, Theunissen I, Van Lierde M
Service de Mathématiques appliquées à la Médecine, UMED 7225 Université Catholique de Louvain, Bruxelles, Belgique.
J Gynecol Obstet Biol Reprod (Paris). 1992;21(4):398-402.
Examination of 8,312 deliveries shows that the difference in weight between boys and girls at birth can be explained completely by the difference in their length. The sex of the child has no influence on the length of the pregnancy. This is influenced by the birth order, the propensity to smoke (tobacco), the mother's weight gain in pregnancy and her social level. The speed of intrauterine growth is influenced by the sex of the fetus, the number of pregnancies she has had, by tobacco, and by the amount of education she has had and her weight gain in pregnancy.
