Successful use of "Hour 1" transfer of sperm microinjected oocytes in natural cycles of poor responder women: a prospective randomized controlled pilot study.

The aim of the study is to demonstrate the successful use of "Hour 1" transfer of sperm microinjected oocytes in natural cycles of poor responder women. Seventy women were selected from 92 consecutive poor responders undergoing intracytoplasmatic sperm injection (ICSI) in a natural cycle at our Sterility and Assisted Reproduction Unit from September 2009 to July 2013, and randomly distributed in two homogeneous groups: Group A or B. Women in Group A (35) underwent transfer within 1 h after ICSI; Group B (35, control group) underwent transfer 3 days after ICSI. In Group A, seven clinical pregnancy and one miscarriage occurred; in Group B, eight clinical pregnancies and two miscarriages were observed. Pregnancy, miscarriage, term pregnancy and overall live birth rates' difference between the two groups was not statistically significant (p > 0.05). Difference between the two groups in terms of timing, type of delivery and newborn birthweight was not observed. Neither ectopic pregnancy nor multiple pregnancies occurred. "Hour 1" uterine transfer of ICSI oocytes, still to be considered with caution because of the relatively low number of observations of the pilot study, deserves further attention on a larger scale, and might be evaluated for clinical and financial effectiveness in other clinical settings.