Figure 2.

Survival curves and 95% Hall-Wellner confidence bands comparing weekly, every other day, and daily intercourse on simulated time to pregnancy over 12 cycles of follow-up among 100,000 women^a,b

^a Anovulation set equal to 8% for each cycle of observation; probability of implantation|fertilization = 70% and probability of fertilization|sex & ovulation = 59% for the first cycle of observation, followed by a 7.5% reduction per cycle for implantation|fertilization and fertilization|sex & ovulation; probability of implantation calculated using Equation 1

^b Scenario 1 relationship between sex and implantation: among fecund couples attempting conception, the maximum probability of attaining pregnancy is ~38% when sexual intercourse always occurs in the fertile window (sex = 1.0)¹⁵.