RELATIONSHIP BETWEEN ENDOMETRIAL THICKNESS AND PREGNANCY OUTCOMES IN ASSISTED REPRODUCTIVE TECHNOLOGY CYCLES

OBJECTIVE: To explore the relations of different ultrasonic endometrial thickness (EMT)values on hCG trigger day and the pregnancy rate (PR) after fresh embryo transfer (ET) in controlled ovarian stimulation (COS) cycles. BACKGROUND: Successful implantation and delivery require both the functional embryo and receptive endometrium in assisted reproductive technology (ART) cycles which is an expensive procedure with low implantation and pregnancy rate (PR). It is estimated that embryos account for one-third, and suboptimal endometrial receptivity for the remaining two-thirds of implantation failures. There is still an ongoing debate regarding the predictive ability of ultrasonic endometrial evaluation on the day of human chorionic gonadotrophin (hCG) trigger during controlled ovarian stimulation (COS) on the outcomes of pregnancies after in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI). METHOD: A retrospective review of data from medical records of all patients who underwent COS, oocyte retrieval, IVF/ICSI, and fresh ET between March 2021and July 2022 at Centre for Fertility and Reproductive Medicine (CFRM), St Paul Millennium medical College (SPHMMC) Addis Ababa, Ethiopia. Patients were categorized based on their ET outcome (as pregnant or non-pregnant) and EMT values on the day hCG trigger (groups A <8mm, B 8-12mm, and C>12 in mm) to study and analyze if any relation between endometrial thickness and pregnancy rate existed. RESULTS: A total of 548 records were analyzed. PR was 40.9%. The odds of pregnancy were higher among patients with EMT group B (82.8% vs 74.6%, p=0.05) and was shown to be significant after controlling for the effects of multiple confounding factors. Although receiver operator curve (ROC) analysis indicated that EMT has a limited value to be used as an indicator of the pregnancy rate as evidenced by the area under the curve (AUC) of 0.59 (95% CI= 0.53, 0.63), it was not possible to determine a cutoff of the endometrial thickness value with an acceptable trade-off between sensitivity and specificity CONCLUSION: There is a positive relationship between the EMT measured on the day of hCG injection and PR and that EMT is an independent factor. Further prospective study is needed to explore the issue in more detail in our setup.