Health Care Utilization in the First Year of Life among Small- and Large- for-Gestational Age Term Infants

The objective of the study was to assess if small- and large-for gestational age term infants have greater health care utilization during the first year of life. The sample included 28,215 singleton term infants (37–42 weeks) without major birth defects delivered from 1998 through 2007 and continuously enrolled at Kaiser Permanente Northwest for 12 months after delivery. Birth weight for gestational age was categorized into 3 levels: <10th percentile (SGA), 10–90th percentile (AGA), >90th percentile (LGA). Length of delivery hospitalization, re-hospitalizations and sick/emergency room visits were obtained from electronic records. Logistic regression models estimated associations between birth weight category and re-hospitalization. Generalized linear models estimated adjusted mean number of sick/emergency visits. Among term infants, 6.2 % were SGA and 13.9 % were LGA. Of infants born by cesarean section, SGA infants had 2.7 higher odds [95 % 1.9, 3.8] than AGA infants of staying ≥5 nights during the delivery hospitalization; of those born vaginally, SGA infants had 1.5 higher adjusted odds [95 % 1.1, 2.1] of staying ≥4 nights. LGA compared to AGA infants had higher odds of re-hospitalization within 2 weeks of delivery [OR 1.25, 95 % CI 0.99, 1.58] and of a length of stay ≥4 days during that hospitalization [OR 2.6, 95 % CI 1.3, 5.0]. The adjusted mean number of sick/emergency room visits was slightly higher in SGA (7.8) than AGA (7.5) infants (P < .05). Term infants born SGA or LGA had greater health care utilization than their counterparts, although the increase in utilization beyond the initial delivery hospitalization was small.