Prenatal investments, breastfeeding, and birth order

Mothers have many opportunities to invest in their own or their child's health and well-being during pregnancy and immediately after birth. These investments include seeking prenatal care, taking prenatal vitamins, and breastfeeding. In this paper, we investigate a potential determinant of mothers' investments that has been largely overlooked by previous research—birth order. Data are from the National Longitudinal Study of Youth 1979 (NLSY79) Child and Young Adult Survey, which provides detailed information on pre- and post-natal behaviors of women from the NLSY79. These women were between the ages of 14 and 22 in 1979, and form a nationally representative sample of youth in the United States. Our sample includes births to these women between 1973 and 2010 (10,328 births to 3755 mothers). We use fixed effects regression models to estimate within-mother differences in pre- and post-natal behaviors across births. We find that mothers are 6.6 percent less likely to take prenatal vitamins in a fourth or higher-order birth than in a first and are 10.6 percent less likely to receive early prenatal care. Remarkably, mothers are 15.4 percent less likely to breastfeed a second-born child than a first, and are 20.9 percent less likely to breastfeed a fourth or higher-order child. These results are not explained by changing attitudes toward investments over time. These findings suggest that providers may want to increase efforts to encourage these behaviors at women with higher parity. The results also identify a potential mechanism for the emergence of differences in health and other outcomes across birth orders.