intra cytoplasmic sperm injection
What is ICSI?
Intra cytoplasmic sperm injection (ICSI) is the injection of a single sperm directly into an egg using a special needle and a micromanipulator. It is recommended in cases of severe male infertility or where there have been cases of failed fertilization following IVF previously.
Couples prepare for ICSI in the same way as for routine IVF, i.e. by ovarian stimulation and egg collection. A single motile morphologically normal sperm (if available) is carefully isolated using a pipette and injected directly into the cytoplasm of each mature egg. The fertilized embryos are cultured in an embryology lab as for standard IVF prior to transfer (ideally allowed to reach the blastocyst stage of embryonic development).
ICSI is recommended when:
Sperm counts are very low
Sperm motility is low (sperm moves very slowly or not at all)
Sperm has been surgical retrieved directly from the testicle or from the epididymis (the tubes that store the sperm outside the testis).
There are high levels of antibodies in the sperm.
There is a high level of sperm DNA fragmentation (damage) >30%.
There has been failed fertilization with IVF in the past.
How does ICSI work?
Once you have selected a clinic and a decision has been made to proceed with ICSI, the process may seem daunting. We will guide you through every step of the way with as much written information as possible. Our wonderful counselors will also be available to offer further support if necessary.
Step 1: Stimulating the ovaries
Ovulation induction is the process of stimulating a woman’s ovaries to produce multiple eggs. Hormone injections (follicle stimulating hormone – FSH) must be administered subcutaneously (under the skin) daily for about two weeks. A second type of medication is also given in order to stop your ovaries from releasing these eggs (ovulating) before they are collected.
Step 2: Monitoring
Over a period of about two weeks whilst taking the stimulation drugs you will need to be scanned approximately 2-3 times in order to monitor the number and size of the follicles (each follicle will potentially include an egg). Sometimes blood tests will also be taken at the time of the scan to measure estrogen levels. This will help the doctors decide when the eggs should be collected or whether the drugs need to be increased or decreased in order to optimize your treatment outcome. We can refer you to local clinics for the monitoring process if you are traveling abroad for treatment.
Step 3: Preparation for egg collection
When these eggs are ready (usually when the leading follicle reaches 17-22mm in size), preparations are made for the egg collection. This involves the administration of a hormone injection (human chorionic gonadotropin – hCG) also known as the trigger injection, approximately 36 hours prior to the planned egg collection. This triggers the eggs to mature making them ready for fertilization.
Step 4: Egg collection
Egg collection is usually performed under mild sedation using a minor vaginal procedure under ultrasound guidance during which the fluid in each of the developed follicles is collected. This fluid is simultaneously assessed by an embryologist and the presence/absence of an egg is confirmed.
Step 5: Fertilisation and embryo culture
After the eggs are collected, they are incubated and assessed for maturity. Only mature eggs can be injected with sperm so the ICSI process cannot proceed if there are no mature eggs collected. All mature eggs are injected with a single sperm and incubated overnight during which the eggs will hopefully undergo fertilization. On average it is expected that approximately 75% of eggs will fertilize normally. It is important to note that total fertilization failure may occur in 2-3% of treatment cycles.
The fertilized eggs are then cultured in the embryology lab and their development is monitored. It is recommended that embryos are cultured to the blastocyst stage of embryonic development (day 5 after fertilization) before transferring back to the uterus, in order to assist the embryologists with selecting the embryo(s) with the most potential . Embryos that become blastocysts can be selected as it has been proven that these embryos have a better chance of achieving a pregnancy
Step 6: Embryo Transfer
Embryos can be transferred on either day 2 or 3 (cleavage stage of embryonic development) or day 5 (blastocyst stage of embryonic development) after egg collection. The embryo transfer day will depend on the number of embryos available and their respective quality. The number transferred will depend on maternal age, the quality of the embryo(s), previous fertility history and local legislation. The main aim is to maximize success rates while minimizing the risk of multiple pregnancy.
Step 7: The post-transfer period
It is generally encouraged for women to resume normal activities post embryo transfer. During this time patients take progesterone supplementation (usually pessaries) to support the lining of the uterus and in the event of a positive result, this supplementation continues until approximately week 12 of pregnancy.