Contraception and Lactation

Joyce King, CNM, FNP, PhD


J Midwifery Womens Health. 2007;52(6):614-620. 

In This Article

Contraceptive Effect of Lactation

Lactation itself has a contraceptive effect and is a vitally important factor in child-spacing and limiting family size in developing countries. Elevated levels of prolactin that occur with breastfeeding inhibit the pulsatile secretion of gonadotropin-releasing hormone from the hypothalamus.[5] This in turn interferes with the hypothalamic-pituitary-ovarian axis, preventing estrogen secretion and ovulation. With weaning, prolactin levels decline and ovulation resumes within 14 to 30 days.[5]

The lactational amenorrhea method (LAM) relies on breastfeeding as a contraceptive method. The effectiveness of this method is dependent on the intensity and frequency of infant suckling and the extent to which supplemental food is added to the infant's diet. Women who are amenorrheic and exclusively breastfeed at regular intervals have the same protection against pregnancy for the first 6 months postpartum as women taking combined oral contraceptives (98% efficacy).[7] Effective use of this method depends on several important points: 1) regular intervals are defined as no intervals greater than 4 hours between feedings during the day or 6 hours at night; and 2) exclusive breastfeeding means that supplemental food should not exceed 5% to 10% of total feedings. Supplemental feeding increases the risk of ovulation and pregnancy, even in women who are not menstruating.[7,8] Expressing milk by hand or by pump is less vigorous than suckling and may reduce the maternal neuroendocrine response and increase the risk of ovulation and fertility.[9] Visness et al.[10] observed that 50% of women who are not fully breastfeeding ovulate before 6 weeks, the time of the typical postpartum visit.

After 6 months, or with the resumption of menstruation, the chance of ovulation and risk of pregnancy increase (although with exclusive breastfeeding the contraceptive efficacy of lactation at 1 year is still high [94% efficacy]).[7] LAM is a transitional method of contraception and is most appropriate for women who plan to fully breastfeed for at least 6 months (Figure 1).[9] Women who choose to use this method need counseling during the prenatal, perinatal, and postnatal periods to improve efficacy. Health care providers should provide another method of contraception for the LAM user to self-initiate if she decides to supplement breastfeeding or if she begins menstruating before 6 months postpartum.

Figure 1.

Use of the lactational amenorrhea method for contraception. Reprinted with permission from Labbok et al.[9]

For women who do not breastfeed exclusively, the return of menstruation and ovulation is unpredictable; therefore, the choice of contraception and the timing of contraceptive initiation are critical.


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