Proportionality and gender in small-for-dates and large-for-dates babies.
The head-for-weight indices of 420 small-for-dates (SFD), 338 average-for-dates (AFD) and 445 large-for-dates (LFD) babies were calculated. The mean values were highest in the SFD group and lowest in the LFD group. Significant differences were found between AFD and LFD groups for girls and both sexes together. Within each group the mean value for boys was significantly higher than for girls. The absolute difference between the sexes was about twice the difference between the SFD and LFD groups. In the SFD group no associations could be found between their proportionality by this measure, and the factors associated with their slow intra-uterine growth rate. 60.8% multiparae in the LFD group had previously given birth to relatively large babies. The mean index of the probands in this subgroup was higher than when previous siblings had been of average birth-weight. In all three groups the mean index was higher for babies delivered instrumentally than for those who had spontaneous vaginal deliveries. No differences were found for other perinatal risk factors.
D001724:Birth Weight; D005190:Family; D005260:Female; D006257:Head / Q000033:anatomy & histology*; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D011247:Pregnancy; D011248:Pregnancy Complications; D012306:Risk; D012737:Sex Factors