Gestational age, baby-friendly hospital practices and breastfeeding duration in healthy full-term infants in Hong Kong

Abstract

Early-term birth is a birth occurring between 37 and 39 weeks’gestation and is associated with adverse neonatal outcomes. Breastfeeding can provide numerous benefits to infants and could potentially offset the adverse neonatal effects of early-term birth. However, little is known about the effect of early-term birthon any and exclusive breastfeeding duration. Additionally, early-term infants may be more likely to have a different postnatal hospital experience than term infants, such as being separated from the mother in the early postnatal period. Studies suggest that Baby-friendly hospital practices can affect breastfeeding duration and exclusivity. However, few studies have been conducted to examine if there are any differences in exposure and the effect of Baby-friendly practices on breastfeeding duration in early-term and term infants. Therefore, the objectives of the study were to examine the associations between gestational age in early-term (37 to <39 weeks) and term infants (39 to <42weeks)and 1) the duration of any and exclusive breastfeeding; 2) the time to breastfeeding initiation and the time to first infant formula supplementation; 3) exposure to Baby-friendly hospital practices; and 4) the effect of Baby-friendly hospital practices on the duration of any and exclusive breastfeeding. This research was based on a large (n=2560), two-phase prospective cohort study of healthy mother-infant pairs. Participants were recruited in 2006-2007 and 2011-2012 from the postnatal units of four geographically-distributed public hospitals in Hong Kong. After hospital discharge, participants were followed-up to assess their breastfeeding practices at 1, 2, 3, 6, 9 and 12 months postpartum or until they stopped breastfeeding. Multiple statistical analyses were conducted to assess the study objectives, such as Chi-square tests, logistic regression, Kaplan-Meier survival curves and log-rank tests, and Cox proportional hazard regression. There was no significant difference in the duration of any or exclusive breastfeeding between early-term and term infants (hazard ratio [HR]=1.0; 95% 0.91, 1.10). Early-term infants were significantly more likely to initiate breastfeeding later than term infants, but after controlling for intrapartum interventions, this difference was no longer statistically significant (HR=0.98; 95% 0.90, 1.07). Gestational age also did not have any effect on the time to formula supplementation (HR=0.95; 95% 0.87, 1.04) and the exposure to Baby-friendly hospital practices. Exclusive breastfeeding during postpartum hospital stay decreased the risk of early breastfeeding cessation in early-term (HR=0.70; 95% 0.56, 0.89) and term infants (HR=0.71; 95% 0.60, 0.84), and earlier breastfeeding initiation was associated with a decreased risk of breastfeeding cessation in term infants only (HR=0.87; 95% 0.77, 0.99). In this cohort of early-term and term infants, there was no association between gestational age and breastfeeding duration and exclusivity and there was no difference in exposure to supportive hospital practices. This suggests that, in the absence of other postnatal complications, early-term birth does not lead to a shorter duration of breastfeeding. The timing of breastfeeding initiation and the introduction of infant formula was similar in both groups. Study findings reinforce the importance of supportive hospital practices, especially exclusive breastfeeding during the postpartum hospital stay.