NEW YORK (Reuters Health) – Including the postcoital test in the basic fertility workup does not add substantially to an existing prediction model for spontaneous pregnancy in subfertile couples, a Dutch study has shown.
The postcoital test (PCT), by assessing sperm motility following intercourse, can indicate the presence of a cervical factor, the authors point out in Fertility and Sterility online March 28. However, “data on the prognostic value of the PCT for spontaneous pregnancy in subfertile couples are inconclusive.”
Dr. Esther Leushuis, with the Academic Medical Center in Amsterdam, and colleagues examined the value of adding the PCT to a reference model for predicting spontaneous pregnancy in a cohort of 3021 subfertile couples. For the reference model, the investigators used the Hunault model, which includes five prognostic variables: female age, duration of subfertility, female subfertility being primary or secondary, percentage motile spermatozoa of the first semen analysis, and referral status.
During follow-up, 537 couples (18%) had a spontaneous ongoing pregnancy within 1 year, according to the report.
The mean probability of a spontaneous pregnancy based on the reference Hunault model without PCT was 0.32, compared with 0.29 when the PCT was included, Dr. Leushuis and colleagues found.
They add, “Addition of the PCT outcome as a prognostic variable to a validated prediction model for spontaneous pregnancy did not improve the fit of this model significantly and even led to a nonsignificant reduction in the correct classification of couples who did and did not achieve a pregnancy.”
As they point out, the predictive information from the PCT is already incorporated in other variables based on semen analysis, so the test “adds
no prognostic information to existing models.”
Prognostic value of the postcoital test for spontaneous pregnancy
Fertil Steril 2011