Does intracytoplasmic morphologically selected sperm injection improve embryo development? A randomized...

Area of Science:

• Reproductive Medicine
• Embryology
• Andrology

Background:

• Sperm nuclear vacuoles can impact embryo development and blastocyst formation.
• High-magnification sperm selection (IMSI) has been linked to improved pregnancy and reduced miscarriage rates.

Purpose of the Study:

• To investigate if high-magnification sperm selection influences oocyte fertilization and embryo development.
• To compare intracytoplasmic morphologically selected sperm injection (IMSI) with conventional intracytoplasmic sperm injection (ICSI).

Main Methods:

• A prospective sibling-oocyte study involving 350 ICSI cycles for male infertility.
• Sperm morphology assessed using high magnification (IMSI) on at least 200 spermatozoa per sample.
• Primary endpoints included oocyte fertilization rate and embryo development; clinical outcomes were descriptive.

Main Results:

• Oocyte fertilization rates were similar: 79.1% for IMSI and 77.3% for ICSI.
• Embryo development up to Day 5 was comparable between IMSI and ICSI groups.
• Clinical pregnancy rates were also similar: 34.4% for IMSI-only and 36.7% for ICSI-only embryo transfers.

Conclusions:

• High-magnification sperm selection (IMSI) demonstrated no significant difference in fertilization or embryo development compared to conventional ICSI.
• The prevalence of vacuoles in normal-shaped sperm is low (27.5%).
• Routine IMSI application in unselected assisted reproductive technology patients is not currently advocated.