Effect of the anterior uterocervical angle in unexplained infertility: a prospective cohort study

The present study aimed to evaluate an anatomical region, the anterior uterocervical angle (UCA), to determine whether it plays a role in unexplained infertility.

In this prospective, cross-sectional study, unexplained infertile and healthy fertile (controls) women were compared. The longitudinal and transverse axes of the uterine cervix and uterine corpus were measured by transvaginal ultrasonography. The UCA was determined as the angle between two lines. One line was drawn between the internal and the external os, and the other was drawn through the internal cervical os and was parallel to the lower side of the front part of the uterine wall in the internal os. Demographic characteristics and uterocervical ultrasonographic measurements were compared between the two groups.

Eighty participants, aged from 20 to 35 years, were enrolled (unexplained infertile [n = 30] and healthy fertile women [n = 50)]. The mean lengths of the uterine corpus longitudinal axis, uterine corpus transverse axis, and uterine cervix longitudinal axis were similar between the groups. The mean UCA was significantly higher in healthy fertile women (131.9 ± 22.9 degrees) than in women with unexplained infertility (114.2 ± 17.3 degrees).

The present study shows that a narrow anterior UCA is associated with unexplained infertility.