Stanford JB, Hansen JL, Willis SK, et al. - Researchers analyzed data from the FERTILI study, a prospective observational study performed in five European countries, with data collected from 1992 to 1996, in order to determine if sexual intercourse in the implantation time window (5–9 days after ovulation) affects fecundability. From 661 women, 2,606 cycles had intercourse during the fecund window (from 5 days before to 3 days after the estimated day of ovulation), leading to 418 pregnancies (conception cycles). They estimated the fecundability ratio (FR) of peri-implantation intercourse on fecundability using an established Bayesian fecundability model, while adjusting for each partner’s age, prior pregnancy, the couple’s probability of conception and intercourse pattern(s). Outcomes revealed no correlation between intercourse in the implantation time window and fecundity after adjustment for intercourse in the fecund window and clustering by couple.