Purpose:

To compare pregnancy rates when women have intercourse on self-estimated high and peak fertile days and when they only have intercourse on low fertile days during the fertile window (FW).

Study Design and Methods:

We used a prospective observational cohort study design. Our convenience sample included 124 women who utilized our online charting Web sites to achieve pregnancy from January 2010 to November 2012. Participants used an electronic hormonal fertility monitor (EHFM) or self-observed cervical mucus or both to determine fertility during the estimated FW. Pregnancy rates were determined with Kaplan–Meier survival analysis. Chi square analysis was used to evaluate the efficacy of achieving pregnancy between two different intercourse patterns.

Results:

The pregnancy rate was 87 per 100 women at 12 months when intercourse happened on high or peak days and 5 per 100 when intercourse occurred only on low days of the FW. Chi square analysis showed a greater proportion of pregnancies with intercourse on high and peak fertile days of the menstrual cycle (x2 = 40.2, p < .001, df = 1).

Nursing Implications:

Focusing intercourse on high or peak fertile days during the estimated FW enhances the probability of achieving a desired pregnancy. Fertility awareness-based online charting system is effective in helping women to determine their FW and target intercourse accordingly to achieve pregnancy.