Intra-Cytoplasmic Morphologically-Selected Sperm Injection (IMSI)

Intra-Cytoplasmic Morphologically-Selected Sperm Injection (IMSI) is an advanced laboratory technique that supports ICSI by allowing our embryologists to select sperm at a magnification of 6,000 to 7,000 times their normal size before injection into the egg.

Unlike standard ICSI, where sperm are examined under conventional microscope, IMSI uses high-powered magnification to assess sperm structure in greater detail, particularly the head, nucleus, and vacuole formation.

At Sunfert, we use IMSI when precise morphological assessment may improve treatment outcomes, especially in cases involving:

• repeated fertilisation failure
• severe sperm morphology abnormalities
• previous poor embryo development
• recurrent implantation failure

By combining advanced sperm selection techniques and ultra-high magnification microscopy, IMSI enables our trained embryologists to select sperm with greater precision using specialised laboratory equipment.

Not all patients require IMSI as we recommend it in selected clinical situations where enhanced sperm selection may improve patients’ fertility treatment outcomes.

Our fertility specialists and embryology team may consider IMSI if there is:

• severe abnormal sperm morphology
• repeated IVF or ICSI failure
• poor embryo quality despite fertilisation
• recurrent implantation failure
• high levels of sperm DNA fragmentation (in selected cases)
• advanced paternal age with compromised sperm structure

By personalising our fertility treatment approach, IMSI is used strategically rather than routinely, only when it offers measurable benefit, so our patients do not incur additional costs for procedures that may not be necessary.

At Sunfert, we decide using IMSI for patient’s IVF treatment if:

• ICSI has failed previously
• embryos fertilise but do not develop optimally
• patient have experienced repeated implantation failure
• patient semen analysis shows significant morphological abnormalities

At Sunfert, our specialists conduct a comprehensive fertility assessment before determining whether IMSI is indicated.

Importantly, IMSI is often performed as part of an advanced IVF cycle where laboratory refinement is required and the recommendation is always based on medical evidence, not assumption.

It can be done in 8 steps.

Step 1: Fertility Evaluation

During a fertility assessment, we conduct a comprehensive evaluation for both partners to identify potential factors affecting fertility and guide a personalised treatment plan.

• Both Spouses: Review of medical history, reproductive history, and previous fertility treatment outcomes.
• Female Spouse: Hormonal profile testing, ovarian reserve assessment, and evaluation of the pelvic organs (uterus, ovaries, cervix, fallopian tubes).
• Male Spouse: Semen analysis to assess sperm quality and reproductive potential and Sperm DNA Fragmentation Test to measure the percentage of sperm with damaged DNA, providing deeper insight into the sperm conditions.

This allows our team to determine whether advanced sperm morphology selection through IMSI is clinically justified.

Step 2: Ovulation Stimulation

Hormonal medications will be given by our doctors which used to stimulate the ovaries to produce multiple eggs.

This stage usually starts at Day 2 or Day 3 of the patient’s menstrual cycle and typically lasts about 10 to 12 days depending on the treatment protocol the patient undergoes.

Step 3: Oocyte Pick-Up (OPU)

Also known as egg retrieval, this is a minimally invasive procedure in which our fertility specialist collects eggs from the patient’s ovaries. The procedure typically takes about 20 to 30 minutes to complete.

During OPU, patients are given light anaesthesia or monitored sedation by an anaesthetist, ensuring that they remain comfortable and pain-free throughout the procedure.

Before concluding the procedure, our fertility specialist will carefully examine the vaginal puncture site to ensure there is no bleeding.

After OPU, patients are observed for 1 to 2 hours in our day ward before being discharged home. 

Most patients experience only mild bloating, cramping, or minimal bleeding, and many are able to return to their normal routine the next day.

Step 4: Ultra-High Magnification Sperm Selection

This is where IMSI differs significantly from standard ICSI.

Our embryologists:

• examine sperm under ultra-high magnification
• assess detailed morphology
• evaluate nuclear shape and presence of vacuoles
• Select sperm with optimal structural integrity

Only sperm that meet strict morphological criteria are chosen for injection.

Step 5: Sperm Injection

Inject the selected sperm carefully into the egg cytoplasm with a specialised microinjection tool.

 

Step 6: Embryo Culture & Monitoring

Fertilised eggs are monitored in our laboratory for 5 to 7 days to develop into viable embryos.

Some patients may choose to undergo Pre-implantation Genetic Testing (PGT), such as PGT-A or PGT-M, to screen their embryos before transfer.

To know why some patients choose to have PGT with their IVF treatment, click the link here to learn more.

• PGT-A (Preimplantation Genetic Testing for Aneuploidy)
• PGT-M (Monogenic/Single Gene Disorders)

Step 7: Embryo Transfer

The embryo with the highest chance of success, based on quality and development, will be selected for transfer into the patient’s uterus.

Any remaining embryos will be frozen to give the patient another opportunity at attempting pregnancy in the future.

Step 8: Post-Transfer Support

Patients receive guidance and hormone support while awaiting Beta hCG pregnancy testing.

At every stage, Sunfert provides personalised care, clear instructions, and continuous support to ensure comfort and confidence.

If you are facing fertility challenges, start with a consultation with our specialists. We will guide you through your fertility journey with expertise and compassionate care. 

Make an appointment with our Fertility Specialist today and take the next step toward your parenthood goals.

Question #1: Is IMSI better than ICSI?

• IMSI is not automatically better for every patient. It provides improved sperm selection precision and may benefit cases with severe sperm abnormalities or repeated treatment failure.

Question #2: Does IMSI improve pregnancy rates?

• Evidence suggests IMSI may improve outcomes in selected patients with specific sperm morphology issues, but it is not universally required for all couples undergoing IVF.

Question #3: Is IMSI safe?

• Yes. IMSI is performed using advanced laboratory equipment and follows the same safety principles as ICSI, with enhanced sperm selection.

Question #4: Can IMSI be combined with genetic testing?

• Yes. IMSI can be combined with Pre-implantation Genetic Testing (PGT-A or PGT-M) to screen embryos before transfer.