Prevalence of Antenatally Identified Lactation Risk Factors and Risk of Not Fully Breastfeeding at 6 to 8 Weeks Postpartum.

Extensive missing data, particularly for the primary outcome (28.7%) and key risk factors like prepregnancy BMI and breast growth, required analysis under the assumption that data were missing at random, which cannot be proven. The study was underpowered to detect effects for rare risk factors such as breast hypoplasia, breast reduction surgery, and preexisting diabetes. The sample was drawn from private clinics in one Australian city and was typically English-speaking and partnered, limiting generalizability to other populations. The analysis did not include perinatal risk factors such as cesarean birth or neonatal unit admission, nor sociodemographic factors, which are known to influence breastfeeding. Infant feeding data were limited to full, partial, or formula feeding, so exclusive pumping or donated human milk use were not captured.

Two authors receive salaries from an unrestricted research grant paid to The University of Western Australia by Medela AG, a company that sells breast pumps and lactation supplies.

Do not interpret the lack of significant association for factors like nipple piercing or thyroid disease as evidence that they never impact breastfeeding. This study was underpowered for many of these factors due to low prevalence, and the high rate of missing data means these null findings are uncertain.