Probability of Multiple Birth from IVF

Historically, IVF has been associated with a high rate of multiple pregnancies due to the practice of transferring multiple embryos. Currently, about 20% of IVF pregnancies result in multiple births, the vast majority being twins. The rate of triplets and higher-order multiples from IVF has dropped to less than 1% due to changes in clinical practice.

The trend toward elective single embryo transfer (eSET) has significantly reduced the multiple birth rate from IVF. In the early 2000s, the IVF twin rate was about 30-35%. ASRM guidelines now recommend single embryo transfer for most patients under 38, and the percentage of eSET cycles has increased from about 15% in 2007 to over 70% in recent years.

Multiple pregnancies carry significantly higher risks than singleton pregnancies, including preterm birth (about 60% of twins are born preterm), low birth weight, preeclampsia, gestational diabetes, C-section delivery, and NICU admission. These risks are the primary reason for the shift toward single embryo transfer, which achieves similar cumulative pregnancy rates while dramatically reducing multiple birth rates.