In vitro fertilization is used to treat the infertile couple for whom other conventional forms of treatment have failed to produce a pregnancy.
The In vitro fertilization (IVF) technique is used in various clinical situations: blocked or absent fallopian tubes, low sperm count, abnormal sperm function, endometriosis, and chronic unexplained infertility, for example. IVF involves the use of medications to stimulate the formation of multiple follicles, each of which contains an egg, in the woman’s ovaries. The process of follicle maturation is monitored very carefully with blood tests and sonograms, to document the number of developing follicles and their diameters. Once the appropriate follicle sizes and blood estradiol levels are achieved, a final trigger injection is administered to induce the final follicle (and egg) maturation.
Transvaginal (through the vagina) oocyte (egg) aspiration under ultrasonography guidance is carried out about 36 hours later, prior to the anticipated time of ovulation (egg release). The eggs are isolated in the laboratory by the embryologist and then are placed in union with the sperm. The eggs are then examined closely (under a high powered microscope) for signs of fertilization eighteen to twenty four hours later. Developing embryos are maintained in an in-vitro culture system and are grown to a day 5 or day 6 embryo (blastocyst) and then frozen (cryopreserved). Embryos can be screened for an adequate number of chromosomes or screened for specific inherited diseases (see PGS and PGD). This allows for the selection
of the healthiest embryos. The actual embryo transfer (see frozen embryo transfer or FET) takes place in a future cycle.