What are the stages of in vitro fertilization (IVF)?

After the initial stage of stimulation and monitoring, there are three additional stages of IVF:

Retrieval: Eggs are retrieved through a minor surgical procedure that uses ultrasound imaging to guide a hollow needle through the pelvic cavity. Sedation and local anesthesia are provided to remove any discomfort that you might experience. The eggs are removed from the ovaries using the hollow needle, which is called follicular aspiration. Some women may experience cramping on the day of retrieval, which usually subsides the following day; however, a feeling of fullness or pressure may last for several weeks following the procedure.

Fertilization: During in vitro fertilization (IVF), the sperm is first prepared for combining with the eggs. In a process called insemination, the sperm and eggs are placed in incubators located in the laboratory, which enables fertilization to occur. In some cases where fertilization is suspected to be low, intracytoplasmic sperm injection (ICSI) may be used. Through this procedure, a single sperm is injected directly into the egg in an attempt to achieve fertilization. The eggs are monitored to confirm that fertilization and cell division are taking place. Once this occurs, the fertilized eggs are considered embryos.

Transfer: After in vitro fertilization (IVF), the embryos are usually transferred into the woman's uterus anywhere from one to six days later, but most commonly it occurs between two to three days following egg retrieval. At this point, the fertilized egg has divided to become a two- to four-cell embryo. The transfer process involves a speculum, which is inserted into the vagina to expose the cervix. A predetermined number of embryos are suspended in fluid and gently placed through a catheter into the womb. This process is often guided by ultrasound. The procedure is usually painless, but some women experience mild cramping.

Dr. Benjamin Sandler, MD
Fertility Specialist

IVF involves several different treatment stages:

  • Stage One - Ovarian Stimulation and Monitoring: In order to maximize the patient's chances for successful fertilization, a patient undergoing IVF usually takes hormones in the form of injections to increase the number of eggs produced in a given month. Physicians monitor the woman to follow her ovarian response continuously, allowing them to adjust and time medication dosage appropriately.
  • Stage Two - Ovum Retrieval: With the patient sedated and comfortable, the ova, or eggs, are retrieved through the vagina under ultrasound guidance.
  • Stage Three - Culture and Fertilization: The oocytes, or egg cells, are fertilized with sperm from the male partner. At times, the sperm are put down on top of the oocyte. In other cases, especially when there are fewer than one million living sperm, ICSI, or intracytoplasmic sperm injection, is used catch a single sperm and inject it directly into the oocyte.
  • Stage Four - Embryo Transfer: One or more of the best embryos are transferred directly into the uterus and allowed to implant. The remaining healthy embryos may be cryopreserved (frozen). The pregnancy test is performed eleven days after embryo transfer. In a good program with a high quality laboratory, there is a 50 percent success rate of pregnancy for a woman under the age of 40.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.