What Is In Vitro Fertilization
In Vitro Fertilization
In vitro fertilization, or IVF, is a procedure that involves retrieving eggs and sperm from the bodies of a male and female and placing them together in a laboratory dish to enhance fertilization. Fertilized eggs are then transferred several days later into the female’s uterus where implantation and embryo development will hopefully occur as in a normal pregnancy. The IVF process is performed by physicians who specialize in reproductive medicine and have received additional education and training in the evaluation and treatment of male and female infertility.
The IVF process was originally developed in the early 1970s to treat infertility caused by blocked or damaged fallopian tubes. By 1978, the first IVF baby, Louise Brown, was born in the United Kingdom. Since then, the number of IVF procedures performed each year has increased and the success rates have improved significantly. IVF involves several different treatment stages:
1. Stage 1: 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. Monitoring is performed to continuously follow a woman’s ovarian response, allowing the physician to adjust and time medication dosage appropriately.
2. Stage 2: Ovum Retrieval: With the patient sedated and comfortable, the ova (eggs) are retrieved through the vagina under ultrasound guidance.
3. Stage 3: Culture and Fertilization: The oocytes are fertilized with sperm. At times, the sperm are put down on top of the oocyte. In other cases, ICSI (intracytoplasmic sperm injection) is used catch a single sperm and inject it directly into the oocyte.
4. Stage 4: Embryo Transfer: Between 1 to 3 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 11 days after embryo transfer. In a good program with a high quality laboratory, a woman under the age of 38 should become pregnant approximately 50% of the time.
Preimplantation Genetic Diagnosis (PGD) and Comprehnsive Chromosome Screening (CCS)
Preimplantation Genetic Diagnosis (PGD) and Comprehensive Chromosome Screening are advanced genetic techniques which allow an individual embryo to be analyzed. PGD is a recommended procedure for patients who are carriers of a genetic anomaly or are affected by a genetic condition that drastically reduces the probability of passing the anomaly to their offspring. Additionally, some patients with advanced maternal age or a history of recurrent miscarriages use CCS to select embryos that do not possess chromosomal abnormalities.
PGD or CCS involves the removal and analysis of a limited number of cells from a developing embryo. The analysis of these cells may be performed by fluorescent in situ hybridization (FISH) or polymerase chain reaction (PCR), which allows a geneticist to provide information on the individual embryo’s chromosomal make-up. PGD or CCS cases may require extended embryo culture to allow for enough time for genetic analysis to be performed. In consultation with the patient’s physician and embryology laboratory, the decision of which embryo(s) and how many embryos to transfer will be made.