Accuracy of breastfeeding data on the Massachusetts birth certificate.

In 2003, the question, "Is the infant being breastfed at discharge?" was added to the US standard certificate of live birth. In Massachusetts, this was adapted to, "Are you breastfeeding or do you intend to?" In 2004-5, we compared the mother's answer to the birth certificate question in 2 hospitals, with her infant's feeding record. At Hospital A, 94.8% (290/306) of birth certificate responses matched the record. At (Baby-Friendly) Hospital B, 79.8% (185/232) matched. At the Baby-Friendly hospital, 17.2% (40/232) of women stated intent to formula feed on the birth certificate but breastfed postpartum. No significant sociodemographic differences existed between women whose answers matched or did not match. Although breastfeeding is a desirable health behavior, mothers did not overstate intent. The assumption that a prenatal feeding decision is an independent predictor of breastfeeding practice may be flawed. In the Baby-Friendly hospital, many women apparently made the decision postpartum.