In a previous study on the relations existing between infant weight, placental weight and maternal weight and height a strong positive correlation was found between infant and placental weight as well as a positive correlation between maternal weight before birth and infant and placental weight respectively. This could be confirmed in this extended study on 438 cases, in which also other variables, in particular the maternal weight increase during pregnancy, were investigated. Where as in the previous study it was suggested, that maternal weight acts via placental weight on infant weight, the findings of this study imply, that there is also a direct influence of maternal on infant weight. Taking maternal weight before pregnancy and immediately before birth (uncorrected and corrected for placental and fetal weight) separately, the correlation between maternal weight before pregnancy showed a stronger relation to infant weight than the corrected maternal weight increase during pregnancy.