In Vitro Fertilization (IVF)
During an In Vitro Fertilization Cycle, injectable medications are taken to stimulate the ovaries to develop multiple egg-containing follicles at once. These eggs are removed during a minor surgical procedure called an egg retrieval, after which they are fertilized with sperm. The resulting embryos are grown in the laboratory, typically for five days, and then either transferred into the woman’s uterus or frozen for future use. Below is a general outline of the steps involved in the in vitro fertilization (IVF) process:
A baseline ultrasound and blood tests are performed at the beginning of the menstrual cycle. Then, injectable follicle stimulating hormone medications are started to stimulate the ovaries. These injections are sometimes preceded by a short course of birth control pills or by other medications such as leuprolide acetate depending on the clinical protocol determined by the physician. Once the nightly subcutaneous (under the skin) injections have begun, morning office monitoring with ultrasounds and blood tests is performed every one to three days. The stimulation phase of the IVF cycle typically lasts one to two weeks, and all monitoring takes place at our Greenwich or Tuckahoe locations. When the ovarian follicles have grown to the appropriate size, an injectable medication to trigger ovulation is given and the egg retrieval is scheduled.
The egg retrieval is a brief procedure (about 15 to 20 minutes) which takes place at Greenwich Hospital. Sedation is provided by an anesthesiologist. Under vaginal ultrasound guidance, a needle is inserted through the vaginal wall and into the ovarian follicles. Fluid containing eggs is drained from the follicles and given to the embryologists, who identify the eggs under the microscope.
Embryologists fertilize the eggs, either by allowing them to mix with sperm or by a procedure called intra-cytoplasmic sperm injection (ICSI), in which a single sperm is directly injected into the egg. The resulting embryos are then grown in the lab, typically for a period of five days, ideally until they reach the blastocyst stage. A blastocyst embryo is comprised of two parts: the inner cell mass, which becomes the fetus, and the trophectoderm, which becomes the placenta. The blastocyst can be graded based on its appearance, and the best embryo or embryos can then be transferred back into the uterus. Alternatively, any excess embryos can be frozen for future use. When a patient elects to do preimplantation genetic screening or preimplantation genetic diagnosis, a sample of the trophectoderm is taken at the blastocyst stage and all embryos are frozen until the genetic testing results are received. Frozen embryos can be thawed and transferred into the uterus in a future cycle.