Risk Factors Associated With Delayed Secretory Activation in a Cohort of Nulliparous Women in Western Australia

Delayed secretory activation can negatively impact maternal and child health through increasing the risk of early cessation of breastfeeding. Early cessation of breastfeeding is known to be associated with increased health risks.

To determine the occurrence of, and risk factors associated with, delayed secretory activation in nulliparous women in Western Australia.

This analysis used a subset of participants (n = 183) enrolled in a multicentre trial. Nulliparous low-risk pregnant women were enrolled between 28-32 weeks' gestation and followed until 1 week after birth. The association between self-reported delayed secretory activation status (onset 4 days or more postpartum) and potential risk factors across the following five dimensions was examined: maternal demographics and health behaviours during pregnancy; maternal anthropometry; obstetric and birth outcomes; newborn characteristics; and infant feeding. Any variables that demonstrated significance (p ≤ 0.10) were entered into binary logistic regression models to quantify their association with delayed secretory activation and adjusted for known confounders.

The rate of delayed secretory activation was 43.2% (n = 79) and was significantly associated with body mass index (BMI) category 25 kg to <30 kg/m²: OR 2.83 (95% CI 1.39, 5.77), BMI ≥30 kg/m²: OR 2.51 (95% CI 1.13, 5.55), and gestational diabetes mellitus (GDM): OR (5.06; 95% CI 1.28, 20.08) in bivariate analysis and in the adjusted multivariable model. Among mothers with GDM, 78.6% experienced delayed secretory activation, compared to 21.4% of mothers who did not have GDM.

Nulliparous women, particularly those with GDM, should be supported to initiate early, frequent, and optimal breast stimulation to exclusively breastfeed.