Relationship between use of labor pain medications and delayed onset of lactation.

BACKGROUND Despite estimates that 83% of mothers in the United States receive labor pain medications, little research has been done on how use of these medications affect onset of lactation. OBJECTIVE To investigate whether use of labor pain medications is associated with delayed onset of lactation (DOL). METHODS We analyzed data from the 2005-2007 Infant Feeding Practices Study II, a longitudinal study of women from late pregnancy through the entire first year after birth (n = 2366). In multivariable logistic regression analyses, we assessed the relationship between mothers' use of labor pain medication/method and DOL (milk coming in > 3 days after delivery). RESULTS Overall, 23.4% of women in our sample experienced DOL. Compared with women who delivered vaginally and received no labor pain medication, women who received labor pain medications had a higher odds of experiencing DOL: vaginal with spinal/epidural only (aOR 2.05; 95% CI, 1.43-2.95), vaginal with spinal/epidural plus another medication (aOR 1.79; 95% CI, 1.16-2.76), vaginal with other labor pain medications only ([not spinal/epidural]; aOR 1.84; 95% CI, 1.14-2.98), planned cesarean section with spinal/epidural only (aOR 2.13; 95% CI, 1.39-3.27), planned cesarean with spinal/epidural plus another medication (aOR 2.67; 95% CI, 1.35-5.29), emergency cesarean with spinal/epidural only (aOR 2.17; 95% CI, 1.34-3.51), and emergency cesarean with spinal/epidural plus another medication (aOR 3.03; 95% CI, 1.77-5.18). CONCLUSION Mothers who received labor pain medications were more likely to report DOL, regardless of delivery method. This information could help inform clinical decisions regarding labor/delivery.