|
|
For many, who have waited a long time and undergone multiple tests and treatments in the effort to conceive, any choice that maximizes having a "positive pregnancy test" is surely a welcomed one. In the world of assisted reproductive technology (IVF) this too frequently translates into the transfer of multiple embryos in the hope that "one will take." While many couples may at first view multiple pregnancy (twins, triplets, quadruplets) as a safe, and even desirable outcome, there are inherent risks involved with multiple pregnancies.
Risks of Multiple Gestation: The greatest risk of multiple pregnancy is early labor and premature birth. While the average pregnancy length of a singleton is about 40 weeks, the average length in a twin pregnancy is 36 weeks, and that of a triplet pregnancy is 30 weeks. In triplet pregnancies over 90% are technically 'premature,' but more than a third are severely premature (<32 weeks). In fact, over 75% of triplets require treatment at a Neonatal Intensive Care Unit (NICU), and hospitalization is typically about 1 month. With twin births, approximately 25% require a stay in the NICU. Unfortunately, many children born severely premature have persistent disabilities. Furthermore, multiple gestation pregnancy is associated with an increased risk of maternal complications including gestational diabetes (elevated blood sugar during pregnancy) as well as pre-eclampsia, a hypertensive disease of pregnancy that can lead to serious outcomes including seizures.
Single Embryo (Blastocyst) Transfer: The Presbyterian- Harris Methodist ARTS Program is recognized as a highly successful program in the United States. By limiting the number of embryos transferred, our IVF program has been successful in minimizing the risk of triplet pregnancies (<5%) stemming from IVF, and have essentially eliminated higher order multiple gestations (quadruplets or more).
Our program is currently trying to lower the occurrence of twin pregnancies that is currently a 40-50% in patients with the best prognosis, i.e. patients <37 years of age or those using donor eggs. Good prognosis patients with embryos of excellent quality may be candidates to participate in our elective single embryo (blastocyst) program. In this situation, there are two or more embryos of high quality and the ability to successfully cryopreserve (freeze) at least one embryo. Patients who participate by transferring a single blastocyst that do not conceive are not charged for the subsequent frozen embryo transfer (FET).
Thus far, our data has shown that with the transfer of a single embryo, pregnancy rates are approximately 10% lower for the fresh cycle, but cumulative pregnancy rates for the fresh and subsequent FET cycle are equal. In other words, those couples who qualify for and undergo an elective single embryo transfer that do not conceive will usually conceive in the subsequent FET while virtually eliminating the complications of twin pregnancies. In summary, the risk of twins is reduced from 40-50% with two embryos transferred to about 2% (from identical or monozygotic twinning) with a single embryo transfer, while cumulative (fresh + FET) pregnancy rates are equivalent.
Elective Single Blastocyst Transfer Program: DFW Fertility Associates, in alliance with the Presbyterian-Harris Methodist ARTS program, aims to offer our patients the option of avoiding twin pregnancies, without necessarily having to compromise the chance of becoming pregnant or incur a higher financial burden by taking the "safer route."
Our experience suggests that we can achieve a similar pregnancy rate and minimize the risk of twins, if our patients who fail to conceive following a single embryo transfer, would be willing to return for the transfer of their cryopreserved embryo. Consequently, patients meeting specific criteria are offered free cryopreservation of their embryo(s) for the first two years. Should the single blastocyst transfer not result in an ongoing pregnancy, a FET cycle would be provided free of charge (not including medication). Our data has shown that this would statistically give these patients the same chance to become pregnant as if they had initially transferred two (fresh) embryos in the original cycle with, a greatly reduced risk of multiple pregnancies.
Your physician is available to answer questions concerning single embryo transfer. |
