Inyección intracitoplasmática de espermatozoides (ICSI)

After your fertility assessment and consultation, and once you've decided to proceed with ICSI, the first step is the Ovarian Stimulation Phase. During this stage, you’ll take hormonal medications starting on day two or three of your period for 8-12 days to stimulate your ovaries to produce multiple follicles, which contain eggs.

Normally, only one follicle matures during a menstrual cycle, but the goal of ovarian stimulation is to mature as many as possible to increase your chances of success. Throughout this phase, your doctor will monitor your response with blood tests and ultrasounds, adjusting your treatment if needed. Once the eggs are mature, a "trigger injection" will be given to prepare the eggs for ovulation and the subsequent egg retrieval.

Before ICSI, your healthcare provider will collect both eggs and sperm. For egg retrieval, 34-36 hours after your trigger shot, your eggs will be collected through a brief procedure under sedation or mild anesthesia. Guided by ultrasound, the doctor will use a thin needle inserted into the pelvic cavity to retrieve the eggs. This process typically takes 15-20 minutes.

Sperm collection, unless frozen sperm is being used, occurs on the same day. The sperm provider abstains from ejaculation for two to three days before collecting the sample, which is usually done at home or at the clinic. The sample must be delivered to the lab within 60 minutes. A semen analysis is then performed to assess the quality. In cases of azoospermia, failed vasectomy reversals or other blockage, procedures like sperm extraction may be necessary. Sperm can also be frozen for future IVF use.

During ICSI, an embryologist uses a pipette to hold the mature egg in place on a lab dish. They then immobilize a single sperm and pick it up with a thin needle. The needle is carefully inserted into the egg to reach the cytoplasm, where the sperm is injected. Once the sperm is inside, the needle is withdrawn from the egg.

After ICSI, your healthcare provider monitors the fertilized egg for signs of successful fertilization. Within five to six days, the fertilized egg should develop into a blastocyst. Your provider will assess its size and cell mass to determine its potential for leading to a pregnancy.

Embryo transfer typically occurs on the fifth or sixth day after egg retrieval, but it can be delayed for months or even years by freezing the embryo. Your doctor will discuss the timing with you. During the transfer, a catheter is inserted into your vagina, and the embryo is placed in your uterus using ultrasound guidance. In most cases, ICSI is performed on several eggs at the same time. More than one fertilized egg may be transferred to your uterus to increase the chances of a successful pregnancy. Unused embryos may be frozen for use in a future IVF cycle.

For pregnancy to occur, the embryo must implant in the uterus. Your provider may advise waiting at least two weeks before taking a pregnancy test.

In ICSI, between 50% and 80% of eggs are successfully fertilized. However, problems can occur during the process. Eggs can be damaged, or the egg might not become an embryo after the sperm injection. In some cases, the embryo forms but stops growing.

Other potential risks include a small chance of genetic or developmental defects, though these may be linked to underlying infertility rather than the ICSI procedure itself. Additionally, boys conceived through ICSI may inherit their father’s or donor's infertility, especially if it’s related to the Y chromosome.

The use of ICSI for all people undergoing IVF, including those without male factor infertility or low sperm counts, is considered controversial.