Increased morbidity in severe early intrauterine growth restriction.

OBJECTIVE: To determine the relative frequencies of complications in severe early intrauterine growth-restricted (IUGR) infants.

METHODS: All infants 32 weeks gestation or less with birth weight less than the fifth percentile admitted from January 1991 to December 1998 were identified retrospectively. Two infants were identified for each IUGR case: the subsequent admission with birth weight +/-100 g of the case, and the subsequent admission with the same gestational age. Infants with multiple congenital anomalies, congenital infections or admission after 48 hours of age were excluded. Maternal and neonatal demographic data, neonatal morbidity and mortality until discharge were gathered by chart review.

RESULTS: A total of 39 IUGR identified infants met criteria, with 41 gestational age infants and 33 birth weight infants. Mean birth weights and gestational ages for the IUGR group, gestational age group, and birth weight group were 744 g and 29.6 weeks, 1370 g and 29.7 weeks, and 781 g and 25.5 weeks respectively. Mortality was higher for IUGR infants than gestational age infants (20.5 vs 0%), but less than the birth weight infants (30%). In surviving infants, total ventilator days, total oxygen days, days to full feeds, and patent ductus arteriosis, were higher for IUGR infants than gestational age infants, but less than birth weight infants. Hypoglycemia, direct hyperbilirubinemia, necrotizing enterocolitis (NEC), thrombo-cytopenia, chronic lung disease and feeding difficulties occurred more frequently in IUGR infants than in both other groups. Length of stay for survivors and incidence of retinopathy of prematurity (ROP) was similar for the IUGR and birth weight infants.

CONCLUSIONS: Infants born prematurely who are also severely IUGR have higher neonatal morbidity and mortality when compared to infants of similar gestational age. The surviving IUGR infants had less intraventricular hemorrhage and periventricular leukomalacia than less mature infants of comparable birth weight, but a similar incidence of ROP and length of stay. They had a higher incidence of NEC, direct hyperbilirubinemia and chronic lung disease, probably due to end-organ damage in utero from chronic placental insufficiency. These findings highlight the unique pattern of mortality and morbidity seen in infants with severe early IUGR.