Aim: The aim of this work was to study the effect of letrozole on perifollicular vascularity and outcome in cases of intrauterine insemination (IUI).
Design: A prospective cohort study on 60 women with infertility attending the outpatient clinic in 2 hospitals in Saudi Arabia and undergoing intrauterine insemination preceded by ovulation induction with letrozole. Our study was conducted from January 2021 to December 2021.
Methods: Patients involved in this study were subjected to ovulation induction with letrozole 5 mg beginning from day 3 of the cycle for 5, folliculometry began on day 10-12 to monitor follicular size and endometrium morphology till the trigger timing by hCG. IUI was performed after hCG administration by 36 hours. On the day of the trigger, the peri-follicular vascularity, endometrial thickness, endometrial pattern, and the number of mature follicles were measured using a 2D transvaginal doppler. Pregnancy is confirmed by a blood test.
Results: The study showed that according to the modified grading system, the distribution of all follicles studied (all >17 mm in diameter) was grade1 (n=3), grade 2 (n=11), grade 3 (n=32), grade 4 (n=14), 14 patient got pregnant while 46 cases did not get pregnant (non-pregnant group). The mean baseline level of serum FSH concentration also tended to be high in the low-grade vascularity cycle, but this result was insignificant. There was giving a pregnancy rate of 16.7%, the follicles of high-grade vascularity were associated with a high pregnancy rate (grade 4=57%), (grade 3=18.8%), then cycles with low-grade vascularity with no pregnancy occur in grade 1 and 2 vascularity group (grade 1, 2=0%) this result is significant. Six pregnant patients had an endometrial thickness of 8-10 mm, 8 patients had an endometrial thickness of 10-12 mm, and zero patients had an endometrial thickness <8 mm, In our study the pregnancy rate was 42.9% with a distinct five-line endometrial pattern, 22.9% with hazy five-line Endometrial pattern, and 0% with no endometrial layering.
Conclusion: Perifollicular vascular perfusion appears to be an important factor in determining the outcome in stimulated IUI cycles, and may have clinical implications in assisted reproduction techniques.