Time to conception and the menstrual cycle: an observational study of fertility app users who conceived.

The objective of this research was to evaluate the association between menstrual cycle characteristics (cycle length, cycle-length variability, and their interaction) and the amount of time it takes women to conceive using a robust multiple linear regression. Participants downloaded Ovia Fertility in 2015 indicated that they had just started trying to conceive, and reported conception within 12 months ( = 45,360, adjusted model  = 8835). The average time to conception among women in the adjusted model was 3.