O-178 Timed intercourse for couples trying to conceive: an updated Cochrane systematic review and meta-analysis
Authors: Gibbons T , Reavey J , Georgiou E , Becker C 
Published: June 2022

Study question

Does timing intercourse around the ‘fertile window’ using ovulation detection methods increase the chance of pregnancy in couples trying to conceive?

Summary answer

This update suggests that timed intercourse using urinary ovulation detection may increase the chances of pregnancy in couples trying to conceive. 

What is known already

Development of health apps has surged, with many tracking menstrual cycles, generating ‘fertile window’ predictions for couples hoping to conceive as well as avoid pregnancy. Adjuncts have been marketed to improve the accuracy of ovulation detection, using LH/oestrogen urinary tests and fertility-based awareness method (FAMB) biosensors. These may all influence sexual behaviours, making timed intercourse more widely practiced. Thus, there is an increased need for clinicians and couples to understand the effectiveness of these methods and potential adverse effects such as stress.

Study design, size, duration

A Cochrane systematic review and meta-analysis was performed. The Cochrane Gynaecology and Fertility (CGF) Group trials register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and PsycINFO were searched in January 2022 to identify relevant randomised controlled trials (RCTs). In addition, relevant references lists were checked, and study authors were contacted to obtain unpublished data. 

Participants/materials, setting, methods

Participants: Couples (fertile and subfertile) trying to conceive.

Intervention: Timed intercourse using ovulation detection methods such as digital apps, LH/oestrogen urine ovulation tests, and FABM.

Comparison: Intercourse not timed around the ‘fertile window’.

Two independent authors screened studies and extracted data. Risk ratios (RR) were calculated for dichotomous data and mean differences (MD) for continuous data, with 95% confidence intervals (CI). Heterogeneity was examined via the I² statistic. 

Main results and the role of chance

In this update, 881 references were screened. Six studies were included, involving 2,374 women. 

We are uncertain whether timed intercourse using FAMB resulted in a difference in live birth (RR 0.92, 95%CI 0.73 to 1.16, I²= 0%, 2 studies, 160 women: low-certainty evidence). No other studies reported live birth. We are uncertain whether timed intercourse using FAMB resulted in a difference in clinical or self-reported pregnancy (RR 0.96, 95% CI 0.8 to 1.15, I²=0, 2 studies, 160 women; low-certainty evidence). However, timed intercourse using urinary ovulation detection was associated with higher clinical or self-reported pregnancy (RR 1.28, 95% CI 1.10 to 1.50, I²=0, four studies, 2214 women; moderate-certainty evidence). This suggested that if the chance of a clinical or self-reported pregnancy following intercourse without ovulation prediction is assumed 18%, the chance following timed intercourse with urinary ovulation detection would be 20% to 28%. Subgroup analysis of all ovulation detection methods showed no difference between couples trying to conceive for under 12 months versus couples trying for over 12 months (subfertile). Finally, we are uncertain whether timed intercourse using urinary ovulation detection resulted in a difference in stress (MD 1.98, 95 CI% -0.87 to 4.83, 1 study, 77 women, low-certainty evidence). 

Limitations, reasons for caution

Insufficient studies reported our specified outcomes including live birth (primary outcome), time to pregnancy, stress, and quality of life. Moreover, there were insufficient studies with large sample sizes assessing FABM, a key method used in timed intercourse and fertility apps.

Wider implications of the findings

This update provides evidence for the practice of timed intercourse using urinary ovulation detection. However, the majority of menstrual cycle apps use FABM for which there is currently insufficient evidence to support the use of when trying to conceive. This review highlights key areas where future research should be conducted. 

Trial registration number

not applicable