Effect of endometrial thickness on pregnancy outcome after intracytoplasmic sperm injection

Objective: To identify cut-off value of endometrial thickness required for implantation of embryo after intracytoplasmic sperm injection. Methods: The auasi-experimental study was conducted from July 2011 to June 2012 at an assisted reproductive clinic in Islamabad. Down-regulation of ovaries, controlled ovarian stimulation, oocyte pick-up, in vitro fertilisation, blastocyst transfer and confirmation of pregnancy with beta human chorionic gonadotropin more than 5mIU/ml. Patients were categorised into two groups on the basis of endometrial thickness <8mm and ≥8mm.On ovulation induction, before human chorionic gonadotropin injection, endometrial thickness was measured by trans-vaginal scan. Receiver operating curve was used to define groups on the basis of endometrial thickness cut-off value for pregnancy. The groups were compared in terms of the number of retrieved,mature and fertilised oocytes along with oocyte maturity, fertilisation and implantation rates by chi square test.  Results: There were 282 females; 116(41%) in Group A with endometrial thickness ≥8mm, and 166(59%) in Group B with endometrial thickness ≥8mm. In group A, 6(5%) and in Group B, 95(57.2%) patients had a positive pregnancy test. The number of mature, fertilised oocytes and cleaved embryos was significantly high in Group B (p=0.01; p=0.001; p=0.001respectively). Increase in endometrial thickness enhanced chances of oocytematurity, fertilisation, cleavage and implantation (p<0.0001 each). Conclusion: Endometrial thickness of 8mm was associated with a positive pregnancy outcome after intracytoplasmic sperm injection. Implantation of embryo was facilitated by better oocyte parameters, oocyte maturity, fertilisation and its cleavage in females who exhibited endometrial thickness above the cut-off value.