Elsevier

Obstetrics & Gynecology

Volume 100, Issue 6, December 2002, Pages 1333-1341
Obstetrics & Gynecology

Current commentary
Timing intercourse to achieve pregnancy: Current evidence

https://doi.org/10.1016/S0029-7844(02)02382-7Get rights and content

Abstract

Physicians who counsel women for preconception concerns are in an excellent position to give advice to couples regarding the optimal timing of intercourse to achieve pregnancy. The currently available evidence suggests that methods that prospectively identify the window of fertility are likely to be more effective for optimally timing intercourse than calendar calculations or basal body temperature. There are several promising methods with good scientific bases to identify the fertile window prospectively. These include fertility charting of vaginal discharge and a commercially available fertility monitor. These methods identify the occurrence of ovulation clinically and also identify a longer window of fertility than urinary luteinizing hormone kits. Prospectively identifying the full window of fertility may lead to higher rates of conception. Proper information given early in the course of trying to achieve pregnancy is likely to reduce time to conception for many couples, and also to reduce unnecessary intervention and cost.

Section snippets

The fertile window

Recent research has defined the days of the menstrual cycle during which intercourse is mostly likely to result in pregnancy. Conception is possible from intercourse beginning about 5 days before ovulation extending through the day of ovulation.2, 3 However, conception on the day after ovulation has never been documented.5 This implies that ova may only be fertilizable in vivo for less than a day because spermatozoa can survive for up to 6 days in properly estrogenized cervical mucus.6 Studies

Identifying the fertile window

To optimize the timing of intercourse during the fertile window, a couple must be able to identify this 6-day interval before and including the day of ovulation. Traditional and widely used means of identifying the day of ovulation and the fertile window include basal body temperature and calendar calculations. Newer means include serial ovarian ultrasound, monitoring of hormones in urine, and fertility charting of vaginal discharge. The physiologic basis for these approaches is illustrated in

Clinical recommendation for couples wanting to conceive

Which of these methods should physicians recommend to couples trying to conceive with minimum time to pregnancy, or couples who would like to know the days when intercourse is most likely to result in pregnancy? There are currently no comparative studies to directly answer this question. However, based on the data that we have reviewed, we suggest that the most appropriate methods to identify the entire fertile window prospectively for the purpose of achieving pregnancy would be either

Acknowledgements

The authors thank Richard Fehring, DNSc, and Doug Carrell, PhD, for helpful comments on the manuscript.

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