Using urine ovulation tests to time sex boosts the chance of pregnancy, a review suggests.
Experts examined seven existing studies and found that urinating on ovulation sticks can help women identify the most fertile period in their menstrual cycle.
Timing sex for this fertile period using a urine ovulation test increased the chances of pregnancy and live birth to between 20% to 28%, compared with 18% without using the tests.
The findings related to women under the age of 40 trying to conceive for under 12 months.
The Cochrane review, carried out by the University of Oxford, the Royal Berkshire Hospital in Reading, and the Princess Anne Hospital in Southampton, included data for 2464 women or couples who had been trying to conceive.
Tests Are Easily Available
Tatjana Gibbons, a DPhil researcher at Oxford's Nuffield Department of Women's and Reproductive Health, and lead author on the study, said: "Many couples find it difficult to achieve a pregnancy, which can lead to concerns about their fertility. The finding that a simple and easily available urine test can increase a couple's chance of successful conception is quite exciting because it can empower couples with more control over their fertility journey and could potentially reduce the need for infertility investigations and treatments."
Professor Christian Becker, from the same department, added: "The high threshold of evidence required in a Cochrane review makes even this moderate quality evidence for the effectiveness of urine ovulation tests quite impressive, as well as surprising considering how long they have been available for."
The researchers did warn that because many of the studies were funded by test manufacturers, the results should be interpreted with caution. However, they suggested that if the chance of a live birth without urine ovulation prediction is 16%, the chance of a live birth with urine ovulation prediction is 16% to 28%.
The experts also found that data was too limited to say whether other methods looked at in the study worked or not, with more research needed. These included fertility awareness-based methods such as calendar tracking, monitoring changes in cervical fluid, and body temperature.