Intracytoplasmic morphologically selected sperm injection: a prospective randomized trial.

The aim of this prospective randomized study was to assess the advantages of a new modified intracytoplasmic sperm injection (ICSI) technique called intracytoplasmic morphologically selected sperm injection (IMSI) over the conventional ICSI procedure in the treatment of patients with severe oligoasthenoteratozoospermia. The new procedure consisted of IMSI based on a preliminary motile sperm organellar morphology examination under x6600 high magnification. A total of 446 couples with at least two previous diagnoses of severe oligoasthenoteratozoospermia, 3 years of primary infertility, the woman aged 35 years or younger, and an undetected female factor were randomized to IVF micro-insemination treatments: ICSI (n = 219; group 1) and IMSI (n = 227; group 2). A comparison between the two different techniques was made in terms of pregnancy, miscarriage and implantation rates. The data showed that IMSI resulted in a higher clinical pregnancy rate (39.2% versus 26.5%; P = 0.004) than ICSI when applied to severe male infertility cases. Despite their initial poor reproductive prognosis, patients with two or more previous failed attempts benefited the most from IMSI in terms of pregnancy (29.8% versus 12.9%; P = 0.017) and miscarriage rates (17.4% versus 37.5%). At present, 35 healthy babies have been born following the introduction of this promising technique in daily IVF practice.