IVF

Hormone injections are given to stimulate multiple egg production. Normal ovulation generally results in one egg being released, but retrieving multiple eggs in IVF improves the chances of successful fertilization and implantation, as well as producing eggs and/or embryos to preserve for future use.

This stimulation process usually requires the initial use of Lupron to suppress the ovary to prevent ovulation or the use of Antagon or Cetrotide during the stimulation cycle until the desired time. Daily gonadotropin injections are then added to stimulate the development of the eggs. These are usually given subcutaneously (under the skin) and are generally well tolerated. We then monitor the progress of ovulation induction with ultrasounds and blood estrogen levels over several days.

Egg retrieval is a minimally invasive surgery performed by placing a special needle into the ovarian follicle and removing the fluid that contains the egg. This is a relatively minor procedure and is performed by visualizing the follicles with a vaginal ultrasound probe. A needle is directed alongside the probe, through the vaginal wall and into the ovary. To avoid any discomfort, strong, short-acting intravenous sedation is provided.

Once the follicular fluid is removed from the follicle, the eggs are identified by the embryologist and placed into an incubator. The eggs are fertilized with sperm later that day by conventional insemination. This involves placing approximately 50,000 sperm with each egg in a culture dish and leaving them together overnight to undergo the fertilization process.

Intracytoplasmic Sperm Injection (ICSI)

Sometimes we use intracytoplasmic sperm injection (ICSI) to fertilize mature eggs in the event of sperm or egg abnormalities. Under a microscope, the embryologist picks up a single sperm and injects it directly into the cytoplasm of the egg using a small glass needle. The cytoplasm is where fertilization occurs.

ICSI allows couples with very low sperm counts, poor quality sperm, or women whose outer egg shell (zona pellucida) is too thick for sperm to penetrate to achieve fertilization and pregnancy rates equal to traditional IVF. It is also recommended for couples who have not achieved fertilization in prior IVF attempts or if a low number of eggs are retrieved (< 5).

Assisted Hatching

During assisted hatching, which usually takes place on day 3 of embryo development, the embryo’s zona pellucida is opened using micromanipulation. This helps the embryo to shed its outer coating and, in some cases, improves implantation and pregnancy rates. The opening in the shell is performed using a chemical or laser technology. A very small opening is made to facilitate embryo hatching. This procedure is very quick and can be completed in less than half a second. This technique is beneficial for older women and for women who previously have not achieved pregnancy with IVF.

Whether or not ICSI is used, the eggs are checked the following day for signs of fertilization and again the next day to evaluate early cell division. Once fertilized, they are considered embryos and placed in a nutrient-rich solution called embryo culture medium to promote growth.

Embryo quality is assessed based on several factors, including cell number, regularity of cell size, and degree of fragmentation. The grading of embryos has three purposes:

• To predict the chances of pregnancy from an embryo transfer.
• To determine how many embryos should be transferred to avoid a multiple pregnancy.
• To decide whether the remaining embryos are suitable for cryopreservation.

The first major assessment happens about 48 hours after egg retrieval. At this stage, viable embryos typically have at least four cells. By 72 hours, some embryos should have 6-7 cells or more. Embryos with higher cell counts, uniform blastomeres (cells), and little or no fragmentation are more likely to implant successfully.

If there is a sufficient number of dividing embryos, they are then moved to a special blastocyst media and grown for an additional two to three days. Ideally, embryos will reach the blastocyst stage by day 5 – the same point in development at which they would naturally arrive in the uterus.

Growing embryos to this advanced stage helps fertility specialists better identify which embryos have the highest potential for implantation and pregnancy. It also allows for the transfer of fewer embryos without reducing the chances of success, which helps lower the risk of high-order multiple pregnancy and associated complications.

Embryos may be transferred on day 2, 3, or 5 after egg retrieval. As mentioned above, we prefer to transfer on day 5 when the embryo is at the blastocyst stage. Embryos are placed through the cervix into the uterine cavity using a small, soft catheter. Embryo transfer usually requires no anesthesia.

The embryo transfer is an important variable that could affect the implantation process. Knowing the uterine length by passing a practice catheter is critical so that the embryos can be placed correctly in the uterus. At the time of the embryo transfer, an ultrasound is sometimes used to confirm the correct placement of the embryo transfer catheter.

When the catheter containing the embryos is passed, it should occur in a smooth fashion without trauma to the endometrial lining. This would give the embryos the best chance for implantation and normal development.

Progesterone is routinely given to support the uterine lining, and is administered either by injection or through vaginal application. This continues until 10-12 weeks of pregnancy. At that time, the placenta should be competent to make its own progesterone to maintain the pregnancy.

In those patients who did not have an optimal response or if the embryology is poor, we give estrogen in a pill form to enhance implantation. A blood test is performed 12 days after the embryo transfer to confirm a pregnancy.