Ovulation method use during breastfeeding: is there increased risk of unplanned pregnancy?

Data from two prospective studies of the ovulation method were used to assess pregnancy rates and users' fertility-related behaviors among breastfeeding women. The rate of unplanned pregnancy was less than 1% during the first 6 months of lactational amenorrhea. However, the unplanned pregnancy rate was elevated among breastfeeders during the months after menses return compared with the pregnancy rate during nonlactating cycles. Rates were also elevated at the time when infant feeding supplementation was started. This increase in unplanned pregnancies was not directly attributable to nonadherence to the ovulation method rules; there was some indication that adherence to the rules actually may be increased during those months. Therefore, special emphasis on both the need for improved breastfeeding support to delay menses return and the increased potential for method failure among new users during this period of time should be incorporated into ovulation method training and support programs.