Examining the effect of newborn feeding method on postnatal length of stay and healthcare utilisation among Neonates With In-utero SSRI Exposure (NeoWISE): a retrospective cohort study.

INTRODUCTION

Up to 30% of in-utero selective serotonin reuptake inhibitor (SSRI)-exposed newborns experience withdrawal and up to 60% experience behavioural impacts. Breastfeeding may offer benefits from skin-to-skin contact and transfer of SSRIs through breastmilk. Limited data are available on healthcare utilisation of these newborns beyond neonatal intensive care unit admission. We aimed to identify whether newborn feeding method affected healthcare utilisation in the first 30 days of postnatal life among Neonates With In-utero SSRI Exposure (NeoWISE).

METHODS

This retrospective cohort study included newborns born in Ontario hospitals between 1 April 2012 and 31 March 2020 to beneficiaries of the Ontario Drug Benefit Program who filled at least one SSRI prenatal prescription. Administrative health and birth registry data were used. Newborn feeding methods were available from birth to hospital discharge. Outcomes were postnatal length of stay (LOS), emergency department visit(s) and hospital readmission within the first 30 days of life. Adjusted linear regression models using inverse probability of treatment weights for feeding method were conducted.

RESULTS

The cohort included a total of 5079 NeoWISE participants, with 3321 (65.4%) exclusively breastfed. Formula-fed infants were more likely to have older mothers with an urban residence, lower income quintile, prior live birth, who smoked at delivery and to be born via caesarean delivery; these imbalances were balanced after propensity score weighting. Exclusively breastfed newborns were significantly less likely to have postnatal LOS ≥3 days (11.6% vs 16.3%) (adjusted relative risk (adjRR) 0.84, 95% CI 0.72 to 0.97), but more likely to have emergency department visit (adjRR 1.42, 95% CI 1.03 to 1.97) and hospital readmission (adjRR 1.78, 95% CI 1.21 to 2.62) compared with formula-fed newborns, primarily due to jaundice.

CONCLUSION

Women taking SSRI medication during pregnancy should receive anticipatory guidance about newborn feeding effectiveness, signs of jaundice and when to seek healthcare after birth. In-hospital feeding method was associated with emergency department visits and hospital readmission among NeoWISE. Breastfeeding cessation was not measured and could have affected estimated associations.