Sometimes 2 embryos turn into 3 fetuses. It happens when one of the embryos, post transfer, splits into identical twins and all of the embryos successfully implant.
Your surrogate probably did not embark upon the surrogacy experience with expectations of a demanding, high risk pregnancy. Triplet pregnancies are always high risk, and physical restrictions, bed rest, and c-sections are all routine during triplet pregnancies. Hospitalization during pregnancy is very common. A surrogate who has only experienced uneventful pregnancies previously may not have planned for these types of physical restrictions during this pregnancy. For example, she may not have an alternative care provider available for her own young children. She is also more likely to suffer from serious pregnancy-related complications herself, such as pre-eclampsia or post-partum hemorrhage.
Triplets are also much more likely to be born premature and thus suffer from conditions such as cerebral palsy. The two identicals are at additional risk from complications if they share a placenta. Overall, the likelihood of at least one baby dying or having a significant disability in a triplet pregnancy is significant. While this is obviously a concern for all intended parents, for those intended parents who have chosen to use a surrogate because of their prior history of pregnancy losses or premature deliveries, this is an especially difficult burden to bear.
With a triplet pregnancy, obstetricians may offer selective reduction as one option. Undoubtedly, this is a very difficult position for any parent or surrogate to be in and decisions about reducing (or not reducing) are ideally made by mutual agreement. For this reason, intended parents and surrogates need to be having the “what if” discussions about the possibility of multiples prior to the embryo transfer. Likewise, decisions about the number of embryos to transfer must be made with an awareness of the possibility that embryos can divide. For many people, this means a single embryo transfer is the best choice.