Objective To determine the impact of sexual intercourse around the time of implantation on
the probability of achieving a pregnancy. Design Time-to-pregnancy cohort using day-
specific probability of pregnancy modeling to account for intercourse during the fertile
window. Setting Community cohort. Patient (s) Women trying to conceive naturally, ages 30–
44, without known infertility. Intervention (s) None. Main Outcome Measure (s) Positive
pregnancy test. Result (s) A total of 564 women provided 1,332 complete cycles for analysis …

… To determine the independent effect of peri-implantation intercourse, fecundability ratios
were calculated using day-specific probability of conception models. These models adjust
for an individual’s underlying probability of pregnancy based on their … Intercourse
frequency during the fertile window and during the peri-implantation window was
significantly correlated (p<0.0001). As the number of days with intercourse during the peri-implantation
window increased the probability of pregnancy decreased even after adjusting for age …