Multiple Births and IVF Treatment
At VCRM, we take the issue of multiple pregnancies very seriously. While many couples think of twins as success, we do not share those couples’ enthusiasm. Twins are not twice the fun, as any parent with twins can attest. We are striving very hard to limit the number of twins, and eliminate the occurrence of higher order multiples (see below) using techniques such as embryo selection and blastocyst transfers, and the introduction of elective single embryo transfer. The American Society for Reproductive Medicine (ASRM) put a statement about the risks of multiple pregnancy which can be found at complications_multiplebirths.pdf and this excellent video at http://www.reproductivefacts.org/Multiple_pregnancy_video/
Conception of a twin gestation is a possible outcome of almost every treatment involving assisted reproductive technology, including IVF. Approximately one third of IVF conceptions at VCRM result in a twin birth. Many of our IVF patients consider a twin pregnancy a very desirable success. While we are constantly attempting to refine and improve IVF technology to reduce the risk of multiple gestation, we recognize that there will likely always be some chance of conceiving a twin pregnancy through IVF – and our patients should realize this as well. Techniques of blastocyst culture and transfer practiced at VCRM have substantially reduced the chances of multiple conception, without sacrificing a patients’ overall chance of pregnancy. In selected cases, we perform single-blastocyst embryo transfers for patients in whom a twin gestation is not acceptable or when medically contraindicated.
High Order Multiples
A high-order multiple pregnancy is a conception consisting of 3 or more fetuses. While the rare successful delivery of very high-order multiple pregnancies might receive international attention in the press (we do not want you to be in the news and we do not want to be in the news either!), it is important to remember that most high-order gestations end in premature delivery. Prematurity carries a significant risk of complications for both mother and babies. When deciding on the number of embryos to recommend for transfer, we carefully weigh all factors with the goal of offering each patient the highest chance of pregnancy with the lowest possible risk of a high-order multiple gestation (we have this discussion again at the time of embryo transfer). Blastocyst culture and transfer has brought about a dramatic reduction in the incidence of high-order multiple pregnancy, and our ultimate goal is to reduce this incidence to zero. There are significant challenges to raising multiples, some of which have been recently discussed in this ASRM publication raising multiples.pdf
“Sufficient unto the day is one baby. As long as you are in your right mind don’t you ever pray for twins. Twins amount to a permanent riot; and there ain’t any real difference between triplets and an insurrection.” Mark Twain, The Baby Speech 1879.
Multifetal reduction (or selective fetal reduction) is a technique developed as a possible alternative method of managing the risks associated with high-order multiple gestation. It is known that twins carry a lower risk of premature delivery than triplets or quadruplets. Selectively reducing the number of viable fetuses carried down to two has been shown in some studies to reduce the risk of premature delivery, and thus fetal complications related to prematurity. The procedure is performed by a perinatologist (high-risk obstetrician) at approximately 11-12 weeks gestational age (beyond the usual time of spontaneous pregnancy loss). The multifetal reduction procedure itself carries some risk of complication that may result in the loss of the entire pregnancy, and does not provide a guarantee of full term delivery. While high-order multiple pregnancies are not a common outcome of IVF at VCRM, multifetal reduction can be considered as an option for patients who find themselves in this unexpected position. The issues surrounding this procedure are complex; our physicians and nurses can provide information regarding the procedure, but patients considering this option will be referred for the more detailed, expert counseling that can only be provided by a perinatologist experienced in both selective reduction and management of high-order multiple gestations. This counseling can provide the balanced information necessary for each patient to make the appropriate decision for her individual case. Bear in mind that while we do not want to put you (or us) in this moral dilemma, such cases unfortunately cannot be completely eliminated even though we are doing our best to avoid them.
Elective Single Embryo Transfer (eSET)
We believe the answer to the multiple pregnancy epidemic is the increased implementation of eSET. This means transferring only a single embryo (usually a blastocyst). While multiple studies have shown that the pregnancy rate is slightly lower when replacing a single embryo, as compared to 2, the pregnancy rate is still very high in a selected patient population (< 35 with extra blastocysts to freeze). ASRM recommends the transfer of a single embryo in those patients, as compared to 2 in women with unfavorable prognosis.