Infertility results when, for various reasons, the egg does not meet with a sufficient number and quality of sperm in the woman’s body. The solution is to try to get the sperm to meet and fertilize the egg outside the body, which is known as in vitro fertilization (IVF), often referred to as IVF. This is done by using medication to encourage both ovaries to produce more eggs than in a natural menstrual cycle (with only one egg growing in a natural cycle, IVF has a very low success rate). The eggs are then fertilized and cultured in vitro to 4-8 cell embryos, and then 2-3 of the best developed embryos are selected and placed back into the uterine cavity for further growth and development, a process called embryo transfer. This technique was first introduced in 1978 for couples with tubal infertility, but has now been found to be equally effective for other causes of infertility.