Fertility and Sterility, 84(3), 805-807
A protocol was developed and evaluated for nonovulating breastfeeding women to determine potential fertility with an electronic hormonal fertility monitor. The amount of required abstinence (i.e., days of potential fertility) through the first menstrual cycle indicated by the fertility monitor was significantly lower (17% of the total days) compared with the amount of abstinence (50% of the total days) indicated by the self-observation of cervical mucus.
Fehring, R. J., Barron, M. L., & Schneider, M. (2005). Protocol for determining fertility while breastfeeding and not in cycles. *Fertility and sterility*, *84*(3), 805-807. https://doi.org/10.1016/j.fertnstert.2005.03.042
Fehring RJ, Barron ML, Schneider M. Protocol for determining fertility while breastfeeding and not in cycles. Fertil Steril. 2005;84(3):805-807. doi:10.1016/j.fertnstert.2005.03.042
Fehring, R. J., et al. "Protocol for determining fertility while breastfeeding and not in cycles." *Fertility and sterility*, vol. 84, no. 3, 2005, pp. 805-807.