Probability of Twins from IVF

The twin rate from IVF has decreased significantly, from about 30-35% in the early 2000s to approximately 12% in 2023. This dramatic reduction is due to the widespread adoption of elective single embryo transfer (eSET), which is now the standard of care for most patients under 38 at their first IVF attempt.

Even with single embryo transfer, identical twinning occurs at a slightly higher rate with IVF (about 2-4%) compared to natural conception (about 0.4%). The higher rate may be related to manipulation of the embryo during laboratory culture and transfer. When two embryos are transferred, the twin rate rises to about 30-40%.

Twin pregnancies carry significantly higher risks than singletons. Preterm birth occurs in about 60% of twins (vs 10% of singletons), and the NICU admission rate for twins is about 40% (vs 10%). The average hospital cost for delivering twins is approximately $100,000 compared to $15,000 for a singleton. ASRM guidelines strongly encourage single embryo transfer to minimize these risks, particularly for patients under 38 with good prognosis embryos. Cumulative success rates with sequential single embryo transfers are comparable to double embryo transfer.