Failed fertilization in vitro: Second day micromanipulation of oocytes versus reinsemination

Objective: To compare routine reinsemination with 2nd day micromanipulation in patients with poor day 1 fertilization. Design: A retrospective review of patient records. Setting: The Mount Sinai Medical Center Assisted Reproductive Technologies Program. Participants: Patients undergoing IVF-ET who had poor fertilization (<35%) with standard insemination and underwent second day reinsemination of oocytes (group I, n = 84) compared with patients who underwent 2nd day micromanipulation with subzonal insemination (group II, n = 12). Main Outcome Measures: Fertilization rate, cleavage rate, number of embryo transfers, and pregnancy rate. Results: Fertilization rate and cleavage rate were significantly higher in group II patients. Pregnancies per transfer were similar between groups I (3/21, 14.3%) and II (0/9, 0%). Second day fertilization was possible in 9 of 12 group II patients, and fertilization rate was higher than day 1 in all nine, however, only 50% achieved cleavage, and none achieved pregnancy. Conclusions: Although micromanipulating oocytes that fail to fertilize may identify occult male factor infertility, may help the clinician plan future cycles, and may result in fertilization and even transfer of embryos in some cycles, there were no pregnancies in our series, and, for now, the clinical efficacy of this procedure remains in question.