Conventional in-vitro fertilization versus intracytoplasmic sperm injection in sibling oocytes from couples with tubal infertility and normozoospermic semen

An auto-controlled study was conducted in couples with tubal infertility and normozoospermic semen. The fertilization rates and embryonic development in sibling oocytes treated, using the same semen sample, either by conventional in-vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) at the same time were compared. Sibling oocyte-cumulus complexes (OCC) of 56 different couples with tubal infertility and normozoospermic semen were randomly divided in order of retrieval into two groups inseminated either by conventional IVF or by ICSI, Of the retrieved OCC in the same cohort, 53.0 +/- 31.2 and 62.0 +/- 26.6% showed two distinct pronuclei after conventional IVF and ICSI respectively (not significant). Complete fertilization failure occurred after conventional IVF in 12.5% (7/56 couples). After ICSI, the comparable figure was 3.6% (2/56), The number of cases was too small to apply a statistical test to this difference. Total cleavage rates were quite similar: 86.7 +/- 28.0 and 90.1 +/- 21% of the zygotes developed into transferable embryos after IVF and ICSI respectively (not significant). Similarly, no difference in embryo quality was observed. Although injection and insemination of the oocytes were performed at the same time in the two groups, at 42 h post-insemination more embryos were at the four-cell stage after ICSI (P < 0.001) than after conventional IVF, where more embryos were still at the two-cell stage (P < 0.02). Embryo transfer was possible in all 56 couples, resulting in 16 positive serum human chorionic gonadotrophin tests (28.6% per embryo transfer), from which a clinical pregnancy resulted in 15 couples. The best embryos were selected for transfer independently of the insemination procedure, but preferably from the same origin. There appeared to be no difference in implantation potency of the embryos obtained with either technique after the non-randomized transfers.