Delayed onset of lactogenesis is common in a cohort of California primiparae

Delayed onset of lactogenesis (delayed OL), defined as late (>72 hours postpartum) onset of copious milk production, is a risk factor for short breastfeeding duration. Our objective was to determine factors associated with delayed OL among a multi-ethnic sample of first-time California mothers who initiated breastfeeding (N=415). The sample was 40% white, 27% Hispanic, 15% African-American, 12% Asian and 6% mixed or other ethnicity. Prevalence of delayed OL was 42%. Variables associated with delayed OL (P < .10, unadjusted) were greater maternal age, education level, and body mass index (BMI), Cesarean delivery, birth weight > 3600 grams, lower Apgar score, postpartum edema, formula intake > 60 mL over first 48 hours, and lack of nipple pain at 24 or 72 hours postpartum. A hierarchical series of logistic regression models was used to examine independent effects of the above variables on the risk of delayed OL. The final model included the following significant (P < .05, adjusted) variables: maternal age, BMI, birth weight and formula use. The prevalence of delayed OL increased progressively across BMI categories: from 31%, to 43%, to 52% among women in the normal, overweight and obese BMI categories, respectively. Excess neonatal weight loss (loss > 10% of birth weight) among infants of mothers with delayed OL was 34.2%, versus 7.8% among infants of mothers without delayed OL (P< .0001). We conclude that delayed OL is alarmingly common, especially among obese women, and is strongly associated with excess neonatal weight loss. Funded by DHHS Maternal Child Health Bureau.