An advanced form of ICSI that examines the internal structure of each sperm at ultra-high magnification — selecting the healthiest sperm at a level of detail standard ICSI cannot reach.
IMSI — Intracytoplasmic Morphologically Selected Sperm Injection — is an advanced form of ICSI in which sperm is selected under dramatically higher magnification before injection. Where standard ICSI uses a microscope magnification of around 400×, IMSI magnifies sperm at 6,000× or more, allowing the embryologist to examine the internal structure of each sperm in far greater detail.
At this level of magnification, subtle abnormalities in the sperm head — particularly vacuoles (small defects in the nuclear material) that are invisible at standard ICSI magnification — can be identified and the sperm excluded from use. The logic is straightforward: selecting a structurally sound sperm to inject into the egg may improve fertilisation, embryo quality, and ultimately the chance of a successful pregnancy.
IMSI is considered an add-on to standard IVF-ICSI — it is not used in every case. The additional time and expertise involved mean it is recommended for specific indications where the quality of sperm selection is likely to be especially important.
A semen sample is prepared and processed to identify the healthiest, most motile sperm — the same starting point as ICSI.
Using a specialised microscope at 6,000× or greater magnification, our embryologist examines the internal structure of individual sperm to identify and exclude those with nuclear vacuoles or other structural abnormalities.
The selected, structurally normal sperm is injected into a mature egg — exactly as in standard ICSI.
Fertilised eggs develop into embryos, which are monitored in our on-site lab.
The best-quality embryo is transferred to the uterus.
IMSI is an advanced add-on procedure, not a replacement for good foundational IVF and ICSI practice. Your doctor and embryologist will advise whether IMSI is likely to benefit your specific situation — we will not recommend it as a blanket add-on without a clear clinical indication.
The evidence for IMSI is most consistent in patients with specific indications — severe teratospermia, previous ICSI failure, or elevated sperm DNA fragmentation. In these groups, studies have shown improvement in fertilisation rates, embryo quality, and in some cases clinical pregnancy rates. In unselected IVF populations, the benefit is less clear. Your doctor will discuss whether IMSI is likely to be beneficial for your specific case.
Both ICSI and IMSI involve injecting a single sperm into an egg. The difference is the magnification used to select the sperm. ICSI uses approximately 400× magnification. IMSI uses 6,000× or more, allowing the embryologist to see internal sperm structure and exclude morphologically abnormal sperm. The injection technique itself is the same.
Sperm DNA fragmentation refers to breaks in the DNA carried within the sperm head. High levels are associated with poor embryo development, IVF failure, and recurrent miscarriage. IMSI can help exclude sperm with visibly abnormal nuclear structure, which often correlates with higher DNA fragmentation — although it is not a direct measure of DNA integrity. Sperm DNA fragmentation testing may be recommended alongside IMSI in some cases.
Yes. IMSI requires additional specialised equipment and significantly more embryologist time than standard ICSI. We provide a transparent cost breakdown including IMSI where it is recommended, so you understand exactly what is involved before you commit.
Yes. IMSI is available at our clinic in Donal Paula, Goa, performed by our resident senior embryologist who has the experience and equipment required. Please discuss at your free first consultation whether IMSI is appropriate for your case.
Your first consultation at White Stork IVF is completely free. No referral needed. No commitment. Speak with our team in Dona Paula, Goa.
