4. Methods of Assisted Reproduction Technology

In vitro fertilization (IVF) was invented to overcome untreatable obstruction or absence (after surgical removal) of the fallopian tubes. To obtain enough eggs for IVF, the ovaries are stimulated with the hormone "follicle stimulating hormone" (FSH) for two weeks until the follicles, which contain the eggs, are mature. A second hormone, "human chorionic gonadotropin" (hCG, which acts like LH) is given to start the process of ovulation - a process that takes about 38 hours. 36 hours after the hCG injection, the eggs are obtained directly from the ovary, (about two hours before intended ovulation) by aspirating follicles through the vagina with the help of ultrasound. Fertilization is achieved in the lab by adding sperm to a culture dish containing the eggs. Two to six days later, several early embryos are transferred into the uterus through the cervix.

Variations are possible. IVF is useful for infertility from causes other than blocked tubes, including unexplained infertility. Because of the fact that in IVF spermatozoa are brought into immediate contact with eggs, fertilization is usually assured, and developing embryos are then transferred to the uterus.

If the fallopian tubes are normal, embryos may be transferred to the fallopian tubes instead (see "ZIFT", below) but for most cases uterine transfer will be just as successful. If the sperm count is reasonable after special preparation, prepared sperm and unfertilized eggs can be placed inside the tubes for fertilization to occur in the normal location ("GIFT"). Recent results demonstrate approximately equal success from IVF and GIFT in couples suitable for either technique. In extreme cases of sperm defects, especially when only a few normal sperm can be isolated from the ejaculate (or, if necessary, obtained directly from the testicles), micromanipulation is used to insert the sperm directly into the egg ("ICSI").