The efficiency and efficacy of IVF and GIFT.

Data relating to the rate of clinical pregnancy obtained with in-vitro fertilization--embryo transfer (IVF-ET) and gamete intra-Fallopian transfer (GIFT) are available for Australia, UK, USA and France. For IVF-ET the value is not affected by the indication but is affected by the age of the woman. The rate of spontaneous abortion, at approximately 20-25% also increases with age and is an important consideration in view of the increased age of patients undergoing IVF-ET. A take-home baby rate of 30% is obtained from an estimated 70% of clinical pregnancies leading to live births and an estimate of 42.8% pregnancies after three attempts. The greater number of oocytes transferred with GIFT may be associated with the increased frequency of multiple pregnancies.