After childbirth the mother’s breasts first produce a yellowish liquid, called colos­trum, which contains antibodies and protein. Lactation, or milk production, begins about one to three days after birth. Pituitary hormones stimulate milk production in the breasts in response to the stimulation of the infant suckling the nipples. If a new mother does not begin or continue to nurse, milk production subsides within a mat­ter of days.

Breast-feeding has many practical and emotional advantages. For the infant, breast milk provides a digestible food filled with antibodies and other immunity-producing substances (J. Hall, 2009). Research has revealed that babies who are breast-fed are less distressed than other infants when experiencing pain or stress (Shah et al., 2006). Breast­feeding through the 6th month also reduces the risk of sudden infant death syndrome by about 50% (Vennemann et al., 2009). A study in Ireland found that breast-feeding was associated with higher reading and writing scores among 9-year-olds, even after controlling for variables in child, maternal, socioeconomic, and socio-environmental characteristics (McCrory & Layte, 2011). For the mother, breast-feeding can be a posi­tive emotional and sensual experience and an opportunity for close physical contact with the baby. Nursing also induces uterine contractions that help speed the return of the uterus to its pre-pregnancy size. Research indicates that breast-feeding may also reduce maternal stress levels (Hahn-Holbrook et al., 2011).

I love seeing the contentment spread over my baby’s face as she fills her tummy with milk from my breasts. It’s an awe-inspiring continuation of our physical connection during pregnancy to see her growing chubby-cheeked from nour­ishment my body provides her. (Authors’ files)

Nursing can temporarily inhibit ovulation, particularly for women who feed their babies only breast milk. However, as we saw in Chapter 10, nursing is not a reliable method of birth control. Estrogen-containing birth control pills should not be used during nursing because the hormones reduce the amount of milk and affect milk quality. Nonhormonal contraception, including the IUD, is an option for postpartum contraception (Glazer et al., 2011).

Nursing also has some short-term disadvantages. For one, nurs­ing causes reduced levels of estrogen, which conditions and maintains vulvar tissue and promotes vaginal lubrication. As a result, the nurs­ing mother may be less interested in sexual activity, and her genitals may become sore from intercourse (Barrett et al., 2000). The woman’s breasts may also be tender and sore. Milk may be ejected involuntarily from her nipples during sexual stimulation—a source of potential amusement or embarrassment. It is often easier to share child-care responsibilities by bottle-feeding than by nursing; the father can have a greater role in holding and feeding the infant. However, a nursing mother can use a breast pump to extract her milk so that it is available to her partner or another caregiver for bottle-feeding the baby (Rasmussen & Geraghty, 2011).

The Centers for Disease Control and Prevention has set a goal for 75% of mothers in the United States to nurse their babies, and the American Academy of Pediatrics and the World Health Organization recommend exclusive breast-feeding for the first 6 months (Norton, 2009). In the United States, 80% of women begin breast-feeding after birth. Six months later, only 15% of women continue breast-feeding exclusively, while 45% continue some degree of breast-feeding (Allers, 2011; Rochman, 2012). Women most likely to have breast-fed were college graduates in the highest income level, and women least likely to have breast-fed were at the lowest education and income levels, residents of the South, teenage mothers, African American mothers, and smok­ers (Ruowei, 2002). Most common reasons for not nursing are medical issues, returning to work, difficulty with nursing, and concern that the baby is not getting enough food (Springen, 2007). Social bias and negative attitudes against women who breast-feed may also be factors (J. Smith et al., 2011). Breast-feeding rates in Sweden are signifi­cantly higher than in the United States, due in large part to generous parental leave of 16 months at 80% of their wages for each parent (Streib, 2011). Of all the industrialized countries, only the United States and Australia lack laws that require paid parental leave with a guaranteed return to work ( Jeffery, 2006).