The Influence of Early-term Birth on NICU Admission, Length of Stay, and Breastfeeding Initiation and Duration

Objective: To examine hospitalization and breastfeeding (BF) experiences for early-term (ET) and full-term (FT) infants to determine if differences existed between them.

Design: Retrospective descriptive cohort study.

Setting: United States 2009.

Participants: Stratified systematic sample of ET (n = 4052) and FT (n = 6825) infants.

Methods: Infants whose mothers completed the Pregnancy Risk Assessment Monitoring System (PRAMS) survey were eligible for inclusion. Extreme discordant phenotype design was used to establish infant groups (ET = 37 weeks/260-267 days; FT = 40-41 weeks/282-294 days). Secondary data analysis was used to examine neonatal intensive care unit (NICU) admission, length of stay (LOS), BF initiation and duration, maternal reasons for BF noninitiation, and predictors of BF start and continuance.

Results: Early-term infants had higher incidences of NICU admission (OR = 1.56), LOS 3-14 days (OR = 1.16), and BF noninitiation (OR = 1.5) when compared (weighted analysis) to FT infants. Early-term gestation was a predictor of BF noninitiation (OR = 1.42) and duration of BF fewer than 4 weeks (OR = 1.309) in nonweighted models. Other predictors of BF noninitiation included African American race, White versus other non-African American race, less maternal education, marital status other, maternal smoking, and maternal medical risk factors. Predictors of shortened BF duration for the sample included African American race versus White race, White versus other non-African American race, less maternal education, marital status other, maternal age younger than age 20 years, and maternal smoking.

Conclusions: Differences in care experienced by ET versus FT infants were identified. Maternal report of ET infant NICU admission and LOS was consistent with studies based on medical records data while new knowledge about ET infant BF patterns emerged.