Maternal asthma is associated with poor breastfeeding outcomes in early postpartum.

BACKGROUND

In infants born to mothers with asthma, breastfeeding may lower the risk of adverse respiratory outcomes; however, breastfeeding rates are low among this group.

OBJECTIVE

To evaluate early breastfeeding outcomes in relation to maternal asthma and determine whether observed associations were mediated by perinatal factors or varied by maternal comorbidities.

METHODS

Data on singleton births were obtained from electronic obstetric records from three local health districts in New South Wales, Australia (2018-2020). Associations between asthma and breastfeeding outcomes were assessed using robust Poisson models fitted within a generalised estimating equation framework. Perinatal factors were sequentially included in models to explore potential mediation of asthma-breastfeeding associations. Interaction between asthma and comorbidities on breastfeeding outcomes was also tested in models.

RESULTS

Among 40,151 births, 4412 (11%) were to women with asthma. Asthma was associated with slightly reduced breastfeeding initiation (adjusted relative risk [aRR]=0.98; 95% confidence interval [CI]: 0.96, 0.99); exclusive breastmilk feeding at birth (aRR=0.98; 95% CI: 0.96, 0.99) and postpartum follow-up (aRR=0.97; 95% CI: 0.94, 0.99); and increased risk of breastfeeding issues (aRR=1.07; 95% CI: 1.02, 1.11). Potential mediators (caesarean birth, preterm birth, low birthweight, neonatal hospitalisation) did not alter associations by >10% for breastfeeding initiation, breastfeeding issues or exclusive breastmilk postpartum. No interaction effects were observed between asthma and maternal comorbidities (body mass index, mental health diagnosis, diabetes) on breastfeeding outcomes.

CONCLUSIONS

Maternal asthma was negatively associated with breastfeeding outcomes in the immediate postpartum period; associations were not explained by perinatal factors or comorbidities. Findings highlight the need for early breastfeeding support for women with asthma.