Maternal factors associated with high birth weight

Maternal characteristics associated with high birth weight were studied in 473 mothers delivered of singleton infants at term with a birth weight of 4500 g or more. The controls were mothers who gave birth to singleton infants at term, with a normal birth weight +/- 1 SD for Swedish newborns. In the multivariate analysis the maximum symphysis-fundus height measurement and gestational duration were strongly significant (p less than 0.001), after correction for other variables, for the probability of being delivered of an infant of high birth weight. Maternal height, weight at beginning of pregnancy, total gestational weight increase and previous live birth of an infant weighing greater than or equal to 4500 g were also important (p less than 0.05) for high birth weight. The maternal characteristics included were evaluated in a prognostic model. With symphysis-fundus height measurement included, the sensitivity increased from 80.3 to 83.3% and specificity from 78.8 to 85.6%, compared with a model where symphysis-fundus measurement was not available.