Regular (ICSI) versus ultra-high magnification (IMSI) sperm selection for assisted reproduction

• Published in: Cochrane database of systematic reviews 2020-02, Vol.2 (2), p.CD010167-CD010167
• Main Authors: Teixeira, Danielle M, Hadyme Miyague, Andre, Barbosa, Mariana Ap, Navarro, Paula A, Raine-Fenning, Nick, Nastri, Carolina O, Martins, Wellington P
• Format: Article
• Language: English
• Subjects: EVALUATION OF SUBFERTILITY TREATMENTS RELATING TO THE FEMALE PARTNER; Female; Gynaecology; Humans; Infertility, Male - therapy; Male; Micromanipulation - methods; Pregnancy; Pregnancy Rate; Randomized Controlled Trials as Topic; Reproductive Techniques, Assisted; Sperm Injections, Intracytoplasmic - methods; Sperm Retrieval; Spermatozoa - physiology
• ISSN: 1469-493X
• DOI: 10.1002/14651858.CD010167.pub3

Subfertility is a condition found in up to 15% of couples of reproductive age. Gamete micromanipulation, such as intracytoplasmic sperm injection (ICSI), is very useful for treating couples with compromised sperm parameters. An alternative method of sperm selection has been described; the spermatozoa are selected under high magnification (over 6000x) and used for ICSI. This technique, named intracytoplasmic morphologically selected sperm injection (IMSI), has a theoretical potential to improve reproductive outcomes among couples undergoing assisted reproduction techniques (ART). However, our previous version of this Cochrane Review was unable to find evidence that supported this possible beneficial effect. This is an update of Teixeira 2013. To identify, appraise, and summarise the available evidence regarding efficacy and safety of IMSI compared to ICSI in couples undergoing ART. We searched for randomised controlled trials (RCTs) in these electronic databases: the Cochrane Gynaecology and Fertility Group Specialised Register, CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, LILACS, and in these trial registers: ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform. We also handsearched the reference lists of included studies and similar reviews. We performed the last electronic search on 18 November 2019. We only considered RCTs that compared ICSI and IMSI; we did not include quasi-randomised trials. We considered studies that permitted the inclusion of the same participant more than once (cross-over or per cycle trials) only if data regarding the first treatment of each participant were available. Two review authors independently performed study selection, data extraction, and assessment of the risk of bias and quality of the evidence; we solved disagreements by consulting a third review author. We corresponded with study investigators to resolve any queries, as required. The updated search retrieved 535 records; we included 13 parallel-designed RCTs comparing IMSI and ICSI (four studies were added since the previous version), comprising 2775 couples (IMSI = 1256; ICSI = 1519). We are uncertain if IMSI improves live birth rates (risk ratio (RR) 1.11, 95% confidence interval (CI) 0.89 to 1.39; 5 studies, 929 couples; I² = 1%), miscarriage rates per couple (RR 1.07, 95% CI 0.78 to 1.48; 10 studies, 2297 couples; I² = 0%, very-low quality evidence), and miscarriage rate per pregnancy (RR 0.90, 95% CI 0.68 to 1.20;