section_path: Methods/Behavioral/Lactation
section_name: Lactation
paragraph_text: Lactation
  
  The lactational amenorrhea method involves the use of a woman's natural postpartum infertility which occurs after delivery and may be extended by breastfeeding. For a postpartum woman to be infertile (protected from pregnancy), their periods have usually not yet returned (not menstruating), they are exclusively breastfeeding the infant, and the baby is younger than six months. If breastfeeding is the infant's only source of nutrition and the baby is less than 6 months old, 93–99% of women are estimated to have protection from becoming pregnant in the first six months (0.75–7.5% failure rate). The failure rate increases to 4–7% at one year and 13% at two years. Feeding formula, pumping instead of nursing, the use of a pacifier, and feeding solids all increase the chances of becoming pregnant while breastfeeding. In those who are exclusively breastfeeding, about 10% begin having periods before three months and 20% before six months. In those who are not breastfeeding, fertility may return as early as four weeks after delivery.