From its inception in the late 1970s, in vitro fertilization has acquired somewhat of a stigma in the public consciousness. People wondered (and continue to wonder) how exactly it worked, how human eggs could be fertilized outside the body rather than within it. Some religious groups find the process especially disturbing and have lobbied against its practice despite the fact that in vitro fertilization remains an excellent option for couples experiencing fertility problems.
In vitro fertilization typically begins with egg stimulation. Fertility drugs are administered to increase a woman’s egg production, given that a woman normally produces only one egg per month. During the fertility drug stage, regular ultrasounds provide physicians with information about the ovaries and blood tests help in maintaining healthy hormone levels. Next, a minor surgery called follicular aspiration (egg retrieval) removes eggs from the woman’s body. Normally, egg retrieval is considered an outpatient procedure, which means it does not require a hospital stay and can be conducted in a doctor’s office. Minor anesthetics are administered to minimize pain. If the patient has not responded to the fertility drugs used during the egg stimulation phase, physicians may advise the use of donated eggs.
Following egg retrieval, sperm is placed with eggs that have been evaluated for quality (insemination). Sperm typically fertilizes eggs within a few hours. All of this activity takes place within an environmentally controlled chamber used to simulate the temperature levels of the human body. If the presiding physician determines a couple’s fertility problems are too great, the sperm can be directly injected into the woman’s eggs in a process called intracytoplasmic sperm injection (ICSI). Many fertility clinics advocate ICSI and utilize it for a portion of the eggs even if fertility levels are normal, thus increasing a couple’s chances of success.
After the fertilized egg divides, it is classified as an embryo. Laboratory technicians will routinely monitor the embryo’s development until it is actively dividing. Normally, this process takes roughly five days to begin. If a couple’s fertility problems include a predisposition to specific genetic disorders, fertility clinics recommend a process called pre-implantation genetic diagnosis (PGD), during which laboratory staff extract single cells from each embryo and screen them for genetic abnormalities. While some consider this procedure controversial and not all fertility clinics offer it, pre-implantation genetic diagnosis increases the chances of having a child without serious genetic disorders. Healthy embryos are then transferred (again as an outpatient procedure in a doctor’s office) into the woman’s womb 3-5 days after egg retrieval. The eggs must implant in the lining of the womb in order for a healthy pregnancy to occur.