Maternal perception of the onset of lactation is a valid, public health indicator of lactogenesis stage II

Test weighing is the "gold standard" for documenting lactogenesis stage II. However, this method is impractical for use in population studies. Materna l perception of the timing of the onset of lactation may be a useful proxy for lactogenesis stage II. This study seeks to validate maternal perception of the onset of lactation as a marker of lactogenesis stage II. Women (n = 60) were recruited after cesarean delivery. Beginning at 24 h postpartum ( pp), the onset of lactation was assessed 3 times daily by both test weighin g and maternal perception. Delayed onset of lactation was defined as follow s: 1) milk transfer < 9.2 g/feeding at 60 h pp and 2) maternal perception < greater than or equal to> 72 h pp. Misclassification analyses were conducte d. Multivariate logistic regression, bivariate analyses and Cox survival an alyses were used to evaluate the determinants and consequences of delayed o nset of lactation, using both definitions. The sensitivity and specificity of delayed maternal perception as an indicator of delayed lactogenesis were 71.4 and 79.3%, respectively. Four risk factors for low milk transfer were significant (P < 0.05) or nearly significant (P <less than or equal to> 0. 08) predictors of delayed perception of the onset of lactation. The effects of low milk transfer and delayed maternal perception on breast-feeding dur ation were similarly modified by intended breast-feeding duration. The magn itude and directionality of the P coefficients for the milk transfer and pe rception variables were consistent. On the basis of these results, we concl ude that maternal perception of the onset of lactation is a valid public he alth indicator of lactogenesis stage II.