1. Delays Fertility
Women who nurse frequently during exclusive breastfeeding remained amenorrhoeic longer than infrequent nursers, introduced supplements later and did not resume menses as promptly thereafter. Duration of exclusive nursing and night nursing after supplementation were the major influences on amenorrhoea.
Source: Elias,M.F. "Nursing Practices and Lactation Amenorrhoea." Journal of Biosco Sci, 1968.
2. Breast Cancer
Among both premenopausal and postmenopausal women, risk of breast cancer decrease with increasing duration of lifetime lactation experience although the effect was consistently stronger for premenopausal women.
Source: McTieman, A., Evidence of Protective Effect of Lactation on Risk of Breast Cancer in Young Women." American Journal of Epidemiology, 1986.
After controlling for age at first full term pregnancy and other potentially compounding factors, parity and duration of breast feeding also had a strong influence on the risk of breast cancer. Compared with parous women who never breast fed, women who had breast fed for 25 months or more had a lower relative risk.
Source: Layde, P.M., "The Independent Associations of Parity Age at First full Term Pregnancy, and Duration of Breast Feeding with the Risk of Breast Cancer." Journal of Clinical Epidemiol, 1989.
If women who do not breastfeed or who breastfed for less than 3 months were to do so for 4 to 12 months, breast cancer among parous premenopausal women could be reduce by 11%; if all women with children lactated for 24 months or longer, the incidence might be reduced by nearly 25%.
Source: Newcomb,P. etal. "Lactation and reduced risk of premenopausal breast cancer." N Engl J Med 1994; 330(2):81-87.
Women who were breastfed as infants, even if only for a short time, showed an approximate 25% lower risk of developing premenopausal or postmenopausal breast cancer, compared to women who were bottle-fed as an infant.
Source: Freudenheim, J. "Exposure to breast milk in infancy and the risk of breast cancer." Epidemiology 1994 5:324-331.
3. Uterine Cancer
A protective effect against uterine cancer was found for women who breastfeed.
Source: Brock, K.E., "Sexual, Reproductive, and Contraceptive Risk Factors for Carcinoma-in-Situ of the Uterine Cervix in Sidney. "Medical Journal of Australia, 1989.
4. Ovarian CancerBreastfeeding should be added to the list of factors that decrease ovulatory age and thereby decrease the risk of ovarian cancer.
Source: Schneider, A.P. "Risk Factor for Ovarian Cancer. "New England Journal of Medicine, 1987.
5. Endometrial Cancer
Lactation provides a hypoestrogenic effect with less stimulation of the endometrial lining. This event may offer a protective effect from endometrial cancer.
Source: Petterson B, et al. "Menstruation span- a time limited risk factor for endometrial carcinoma." Acta Obstet Gyneocol Scand 1986;65:247-55.
6. Emotional Health
At one month postpartum, women who breastfed their infants had scores indicating less anxiety and more mutuality than the women bottle feeding their infants.
Source: Virden, S.F., "The Relationship Between Infant Feeding Method and Maternal Role Adjustment." Journal of Nurse Midwives, 1988.
7. Decrease Insulin Requirements
Breastfeeding decreased insulin requirements in diabetic women. Reduction in insulin dose postpartum was significantly greater in those who were breastfeeding than those who were bottle feeding.
Source: Davies, H.A., "Insulin Requirements of Diabetic Women who Breast Feed." British Medical Journal, 1989.
8. Decreased Osteoporosis
The odds ratio that a woman with osteoporosis did not breastfeed her baby was four times higher than for a control woman.
Source: Blaauw, R. et al. "Risk factors for development of osteoporosis in a South African population." SAMJ 1994; 84:328-32.
9. Promotes Postpartum Weight Loss
Mothers who breastfed exclusively or partially had significantly larger reductions in hip circumference and were less above their pre-pregnancy weights at 1 month postpartum than mothers who fed formula exclusively.
Source: Kramer, F., "Breastfeeding reduces maternal lower body fat." J Am Diet Assoc 1993;93(4):429-33.