Ross Laboratories changed its weighting procedures to obtain a better reflection of the socioeconomic makeup of the U.S. population (Martinez and Krieger, 1985), and data for the 1980s from the National Survey of Family Growth were not yet available for the subcommittee's use. The evidence from Ross Laboratories suggests a gradual, persistent decline in breastfeeding during the 1980s.

The initiation of breastfeeding by women delivering in 1989 was reported to be 52.2% (Table 3-2) (A. Ryan, Ross Laboratories, personal communication, 1990). By age 5 or 6 months,² only 19.6% of the infants were still breastfed. Of the three ethnic groups compared, white mothers initiated breastfeeding at the highest rates and black mothers did so at the lowest rates. Forty percent of white mothers who initiated breastfeeding were still breastfeeding at 5 or 6 months, compared with approximately 30% of black or Hispanic mothers. A breakdown of these data by parity indicates that, except among Hispanics, primiparous and multiparous women initiate breastfeeding at about the same rates, but the former breastfeed for a shorter duration. The data also show that married mothers are much more likely than unmarried mothers to breastfeed and that they experience a far lower rate of attrition by 5 to 6 months. This difference is especially pronounced among black mothers.

Higher percentages of older mothers initiate breastfeeding, and they continue for a longer duration than younger mothers do. Breastfeeding both in the hospital and at 5 or 6 months is positively associated with maternal education and family income. Mothers with any college education are especially likely to initiate breastfeeding. Black mothers with a high school education or less initiate breastfeeding only about half as often as college educated black mothers do.

A breakdown of breastfeeding by census region shows distinct regional trends. The highest rates for initiating breastfeeding (Figure 3-2 [in the hospital]) and at 5 or 6 months post partum (Figure 3-3) are found in the Mountain and Pacific regions; rates in the East South Central region are the lowest. Ethnic differences within census regions are the same as those seen in national data.

The Ross Laboratories data on participants in the Special Supplemental Program for Women, Infants, and Children (WIC) indicate that 34% breastfeed