In Vitro Fertilization (IVF)

In a natural reproductive cycle, a group of eggs start to mature during each month, but usually, only one egg fully matures for ovulation, while the rest disintegrate.

During IVF, hormone injections stimulate the eggs in that cycle's group to mature at the same time, potentially yielding multiple eggs for retrieval. The medication type, dosage and frequency are personalized based on factors like your medical history, age, Anti-Müllerian Hormone (AMH) level and prior response to IVF.

Ovarian stimulation involves:

• Monitoring: Ultrasounds and blood tests track how your ovaries respond to the hormones. Monitoring happens frequently, over 8 to 14 days. While individual eggs aren’t visible, your healthcare team will measure ovarian follicles, which each hold a potential egg. Follicles larger than 14 mm generally contain mature eggs ready for retrieval.
• Trigger Shot: Once your eggs are mature, a "trigger shot" is given 34 to 36 hours before retrieval to finalize maturation, preparing the eggs for collection.

While under anesthesia, your healthcare provider inserts a thin needle through the vagina into each ovary using ultrasound guidance. The needle, connected to a suction device, gently extracts eggs from each follicle.

The retrieved eggs are placed in a dish with a special solution and then transferred to an incubator for optimal conditions.

To minimize discomfort, medication and mild sedation are provided during the procedure. Egg retrieval typically occurs 34 to 36 hours after your final hormone injection, known as the "trigger shot."

There are two common methods used to fertilize eggs with sperm:

• Conventional insemination: Healthy sperm and mature eggs are mixed and placed in an incubator.
• Intracytoplasmic sperm injection (ICSI): A single sperm is injected directly into each mature egg. ICSI is typically used when there are sperm quality issues or when fertilization failed in previous IVF attempts.

In some cases, additional procedures may be recommended before embryo transfer:

• Assisted hatching: About 5 to 6 days after fertilization, an embryo hatches from its surrounding membrane to attach to the uterus. If you're older or have had unsuccessful IVF attempts, assisted hatching can help. A small hole is made in the embryo's membrane to aid this process, especially for frozen embryos, which may have a hardened membrane.
• Preimplantation genetic testing: Embryos are allowed to develop until a small sample can be taken and tested for genetic diseases or chromosome abnormalities. Embryos free of issues can be transferred to the uterus. This test reduces—but doesn't eliminate—the risk of passing on genetic conditions, so prenatal testing is still recommended during pregnancy.

Typically, about 70% of mature eggs fertilize. For example, if 10 mature eggs are retrieved, around seven will fertilize and potentially become embryos. If there’s a large number of eggs or you wish to save some for later, unfertilized eggs can be frozen.

Over the next five to six days, embryo development is closely monitored. About 50% of fertilized eggs reach the blastocyst stage, which is optimal for transfer, freezing or genetic testing. Embryos suitable for transfer, and those that were biopsied for genetic testing, will be frozen on day five, six or occasionally day seven for future use.

There are two types of embryo transfers: fresh and frozen. Both follow the same transfer process, but the key difference lies in timing:

• Fresh embryo transfer: The embryo is placed in your uterus 3 to 7 days after egg retrieval.
• Frozen embryo transfer: Previously frozen embryos are thawed and transferred into the uterus. This method is more common and may have a higher success rate for live births, in some cases.

For a frozen transfer, you'll take hormones for 14 to 21 days, followed by injections, to prepare your uterus. A frozen transfer can also be accomplished after a modified natural cycle. Monitoring appointments track your readiness for transfer.

The embryo transfer itself is a quick, simple procedure, similar to a Pap test. A catheter is inserted through the cervix, and the embryos are injected into the uterus. It usually takes less than 10 minutes and doesn’t require anesthesia.