When natural conception methods fail to produce pregnancy, IVF becomes an option. In vitro fertilization (IVF) is a process by which egg cells are fertilized by sperm outside the womb, in vitro. IVF is a major treatment in infertility when other methods of assisted reproductive technology have failed. The process involves hormonally controlling the ovulatory process, removing ova (eggs) from the woman's ovaries and letting sperm fertilize them in a fluid medium. The fertilized egg (zygote) is then transferred to the patient's uterus with the intent to establish a successful pregnancy. The first "test tube baby", Louise Brown, was born in 1978. Initially IVF was developed to overcome infertility due to problems of the fallopian tube, but it turned out that it was successful in many other infertility situations as well. The introduction of intracytoplasmic sperm injection (ICSI) addresses the problem of male infertility to a large extent. (Male infertility consists of failure to produce sperm.)

For IVF to be successful it may be easier to say that it requires healthy ova, sperm that can fertilize, and a uterus that can maintain a pregnancy

IVF can be used for females who have already gone through menopause. The donated oocyte from a healthy young woman can be fertilized in a crucible. If the fertilization is successful, the zygote will be transferred into the uterus, within which it will develop into an embryo.