The strain rate of endometrium measured by real-time sonoelastography as a predictive marker for pregnancy in gonadotropin stimulated intrauterine insemination cycles.

Aim: Sonoelastography is an imaging technique that measures tissue strain quantitatively. This study aims to investigate whether the strain rate of endometrium measured by elastography can predict pregnancy after intrauterine insemination (IUI).

Methods: This study examined 197 gonadotropin-stimulated IUI cycles of 148 women diagnosed with unexplained infertility from February 2019 to November 2020. Endometrial thickness, pattern, and strain rate were measured by transvaginal ultrasonography immediately before the insemination. The endometrium and the parametrial tissue were selected for regions of interest, and the strain rate was calculated. The measurements were analyzed concerning the IUI outcome.

Results: Of the 197 IUI cycles, the pregnancy rate was 15.20% (n = 30), and ongoing pregnancy rate was 12.2% (n = 24). The mean strain rates were not different between pregnant and nonpregnant groups (2.68 ± 1.28 vs. 2.81 ± 1.32, p = 0.651). Strain rate was not predictive for pregnancy, shown by receiver operating characteristic curve analysis; the area under the curve was 0.526 (95% CI 0.413-0.639; p = 0.649). Pregnancy rates were significantly affected by the women's age and the inseminated sperm count. In multiple logistic regression analysis, the other parameters, including body mass index, anti-Müllerian hormone, endometrial thickness, endometrial strain rate, and echogenic endometrial pattern, did not significantly change the odds ratio of pregnancy.

Conclusion: The endometrial strain rate does not significantly affect the pregnancy rates in gonadotropin stimulated IUI cycles. It appears that strain rate does not predict IUI outcome. More research is needed to evaluate the usefulness of sonoelastography in infertility treatments.