Predictive factors for multiple pregnancy in in vitro fertilization

OBJECTIVE: To study predictive factors influencing the multiple pregnancy rate in in vitro fertilization (IVF). STUDY DESIGN: Retrospective study. RESULTS: In 1,736 IVF cycles, 453 pregnancies occurred. The rate of singleton, twin and triplet pregnancies was 44%, 22% and 4.5%, respectively. Eighty-one percent of these clinical pregnancies ended with a delivery, giving a "take-home baby" rate of 23.8%/oocyte retrieval. As expected, a statistically significant positive correlation was found between the number and quality of embryos replaced and the occurrence of multiple pregnancies. A statistically significant correlation was also found when parameters such as age, stimulation parameters and embryo characteristics were incorporated into the analysis. This correlation was different for singleton, twin and triplet pregnancies. CONCLUSION: Based on the findings of this study, in patients with a good prognosis for IVF outcome, only two embryos of good quality should be replaced regardless of the maternal age or number of IVF attempts.