Body proportions and early neonatal morbidity in small-for-gestational-age infants of successive births

Background. We wanted to examine if infants who were small for gestational age (SGA) at term had increased perinatal mortality or morbidity compared to non-SGA infants, and if this could be related to the infant's body proportions, or to whether the mother previously had delivered a low-birthweight infant (''repeater'') or not (''non-repeater''). Methods. From a cohort of 5722 para 1 and para 2 women, we compared perinatal mortality in 541 SGA (birthweight <10th percentile) and 4737 non-SGA infants. From the same cohort, early neonatal morbidity was studied in 368 SGA and 462 control infants without congenital malformations, Results. SGA infants had a 6.4 (95% CI: 2.6-15.7) higher risk of perinatal death than controls, but when infants who died with congenital malformations were excluded, this risk was not significantly increased. SGA infants were more often transferred to an intensive care unit than controls (1.7, 95% CI: 1.0-2.9). Among SGA births, infants with asymmetric body proportions (i.e. low ponderal index) more often had symptoms in the neonatal period (RR: 2.5; 95% CI: 1.4-4.3) and were more often transferred to an intensive care unit (3.4; 95% CI: 1.6-7.4) than symmetric SGA infants, whereas there were no differences between SGA infants of repeaters and non-repeaters. Conclusions. We found that SGA infants had higher perinatal mortality than controls, but this was due to a higher prevalence of congenital malformations. Among SGA infants without malformations, our results indicated increased neonatal morbidity in infants with asymmetric body proportions.