The Effect of Morphological Parameters on IVF Outcomes in Single Blastocyst Transfer Cycles

Aim: Our aim is to evaluate the effect of three morphological parameters (Blastocoel expansion, trophectoderm (TE) morphology grade, and inner cell mass (ICM) morphology grade) on clinical pregnancy in single blastocyst transfers. Methods: The study included 74 fresh day 5 single blastocyst transfers in a two-year period. There were 30 women with clinical pregnancy (Group 1). Women that failed to get pregnant after IVF/ICSI procedure were included in the non-pregnant group (n = 44) (Group 2). The blastocysts were graded according to Gardner and Schoolcraft. Age of the couple, body mass index, infertility duration, day 3 follicle stimulating hormone, luteinizing hormone, number of days of gonadotropin stimulation, total gonadotropin dose, estradiol level on the day of hCG administration, number of oocytes retrieved, number of metaphase II oocytes, number of 2PN, TE morphology, ICM morphology, blastocoel expansion were recorded. These outcomes were compared between the two groups. Statistical comparisons were carried out by Chi-square test and Student “t” test. Regardless of the statistical test, only a p value ≤ 0.05 was considered significant. Results: During the study period, 702 embryo transfers were performed; of these 74 (10.5%) were on Day 5. While number of oocytes retrieved, number of metaphase II oocytes and 2PN increased in pregnant group, estradiol level on the day of hCG administration, total gonadotropin dose, blastocoel expansion were similar in both groups. ICM and TE morphology were significantly associated with pregnancy (p<0.05). Conclusion: The clinical pregnancy rate seems to be affected by both ICM and TE morphology.