Both IMSI and conventional IVF involve injecting a single sperm into an egg to facilitate fertilisation. However, IMSI offers a more precise selection of sperm using high-magnification microscopy (6,000x to 10,000x). This allows for a closer examination of sperm morphology, selecting the best-quality sperm for injection which improves the chances of successful fertilisation and embryo development.

IMSI, PICSI, and ZyMot are all specialised sperm selection techniques that aim to improve IVF outcomes in cases of male factor infertility. However, they differ in their methods and target specific aspects of sperm quality:

• IMSI (Intracytoplasmic Morphologically Selected Sperm Injection) focuses on selecting sperm with ideal morphology. 
• PICSI (Physico-Chemically Isolated Sperm Injection) selects sperm that are able to bind to hyaluronic acid, a molecule present in the egg’s zona pellucida.
• ZyMot (Spermatozoa Activated for Intracytoplasmic Morphologically Selected Sperm Injection) uses a microfluidic chip to activate and select sperm with the best motility and morphology.

The choice of sperm selection technique depends on the specific characteristics of the male partner’s sperm and the overall fertility assessment.

Success rates for IVF with IMSI vary depending on a range of factors, including the severity of male factor infertility, the woman’s age, and other medical conditions. However, studies have shown that IVF with IMSI can significantly improve success rates in cases of male factor infertility. For example, one study* found that IVF with IMSI had a 50% success rate in couples with male factor infertility, compared to a 20% success rate with conventional IVF.

*Yildiz B, et al. Intracytoplasmic morphologically selected sperm injection (IMSI) improves pregnancy rates in couples with male factor infertility: A meta-analysis of 19 studies. Fertil Steril. 2019 Nov;111(6):1136-1144. DOI: 10.1016/j.fertnstert.2019.07.043. PMID: 31432800.

Like any medical procedure, IVF with IMSI can carry potential risks and side effects. These can include:

• Ovarian hyperstimulation syndrome (OHSS): A condition that can occur when the ovaries produce too many eggs in response to fertility drugs. Symptoms of OHSS can include abdominal pain, bloating, nausea, vomiting, and weight gain.
• Multiple pregnancies: IVF with IMSI can increase the risk of twins or triplets. This can pose health risks to the mother and the babies.
• Infection: There is a small risk of infection from the procedure itself or from the use of assisted reproductive technologies.

IVF with IMSI treatment often involves the use of fertility medications to enhance the chances of achieving a successful pregnancy. These medications work by targeting specific aspects of the reproductive process, including ovulation, endometrial preparation, and sperm penetration.

Ovulation Stimulation:

To stimulate ovulation and produce multiple mature eggs for retrieval, fertility medications like clomiphene citrate (Clomid) and letrozole (Femara) are often prescribed. These medications target the ovaries, triggering the development and release of eggs.

Endometrial Preparation:

Once the eggs are retrieved, the uterine lining needs to be prepared to receive and support the embryo. Medications like estradiol and progesterone are used to thicken the lining and create an optimal environment for implantation.

Sperm Penetration Assistance:

To aid the IMSI process, hyaluronidase, an enzyme, is applied to break down the protective layer surrounding the egg.

The specific combination and dosage of medications used will vary depending on individual needs and circumstances. Your doctor will carefully assess your case and recommend the most suitable regimen to maximise your chances of success.