Very slight elements of risk are associated with any medical intervention but for IVF the most notable risk in the past has been multiple births. The impact of multiple births on birth weight, premature delivery, and post-natal complications is well known. This is largely due to the practice over the past 30 years of transferring two or more embryos during IVF. Thanks to PGT-A testing and Single Embryo Transfer (SET), however, doctors can now feel confident about transferring just one normal embryo. At RMA, we have established SET as the standard of care going forward. With SET, the risk of multiple births is drastically reduced.
The major complication of IVF is the risk of multiple births. This is directly related to the practice of transferring multiple embryos at embryo transfer. Multiple births are related to increased risk of pregnancy loss, obstetrical complications, prematurity, and neonatal morbidity with the potential for long term damage. Strict limits on the number of embryos that may be transferred have been enacted in some countries (e.g. Britain, Belgium) to reduce the risk of high-order multiples (triplets or more), but are not universally followed or accepted. Spontaneous splitting of embryos in the womb after transfer can occur, but this is rare and would lead to identical twins. A double blind, randomised study followed IVF pregnancies that resulted in 73 infants (33 boys and 40 girls) and reported that 8.7% of singleton infants and 54.2% of twins had a birth weight of less than 2,500 grams (5.5 lb).
With egg donation and IVF, women who are past their reproductive years, have infertile male partners, have idiopathic female-fertility issues, or have reached menopause can still become pregnant. Adriana Iliescu held the record as the oldest woman to give birth using IVF and a donor egg, when she gave birth in 2004 at the age of 66, a record passed in 2006. After the IVF treatment some couples are able to get pregnant without any fertility treatments. In 2018 it was estimated that eight million children had been born worldwide using IVF and other assisted reproduction techniques.
Repeated failed rounds of IVF can help identify causes of infertility. For example, if sperm and egg quality are normal, then the conception issue may be rooted at the embryonic or implantation level. In other words, if IVF fails to result in pregnancy despite successful fertilization, embryonic development or implantation may be to blame. Still this is a very expensive way to start getting answers.