A Cochrane review (abstract «»1, review «»2) included 9 intervention groups and 2 control groups in observational studies. Lactational amenorrhea method (LAM) is defined as a method during the first 6 months postpartum in amenorrheic women who are fully or nearly fully breastfeeding. For the outcome two controlled studies of LAM users reported life table pregnancy rates at 6 months of 0.45 and 2.45 percent, one controlled study reported 5% pregnancies in the absence of life table rates per month, and 8 uncontrolled studies of LAM users reported 0–7.5 percent. Life table pregnancy rates of women fully breastfeeding and amenorrheic but not using any contraceptive method were 0.88 in one study and 0.9–1.2 percent (95% CI 0. 0–2.4 ) in a second study, depending on the definition of menstruation used. The life table menstruation rate at 6 months in all studies varied between 11.1–39.4 percent.