CCRM’s ultimate goal is to help our patients achieve successful singleton pregnancies. Although, twins or “multiples” might seem ideal for those undergoing in vitro fertilization (IVF), the fact is this scenario poses significant risks for both the mother and children, such as pre-eclampsia, postpartum hemorrhage, maternal mortality, miscarriage, gestational diabetes, as well as pre-term labor and preterm delivery.
Twins also account for a significantly increased percentage of respiratory distress syndrome and neonatal intensive care unit admissions. The likelihood of neonatal mortality had been shown to increase seven-fold for twins over singleton pregnancies. Additionally, the risk of severe physical impairments and cognitive delays has been shown to increase by 1.7-fold in twin pregnancies.
Physicians and scientists at CCRM have been in the forefront of creating enhanced laboratory conditions, which allow for elective single embryo transfer resulting in extremely high pregnancy rates, while minimizing the risk of multiples. CCRM was one of the first clnics in the world to successfully culture embryos to the blastocyst stage (day 5 and 6 after ooctye aspiration). These embryos are associated with a much higher pregnancy rates after transfer. In a groundbreaking randomized trial of women undergoing elective single versus two blastocyst stage embryo transfer, scientists and physicians at CCRM demonstrated that ongoing pregnancy rates were no different when patients received one versus two embryos, but the multiple pregnancy rate was reduced from 50% to 0 with transfer of a single embryo.
For these reasons, American Society for Reproductive Medicine now recommends single embryo transfer in women under 40 undergoing blastocyst transfers, all women using an egg donor, and all of those transferring embryos predicted to be normal after undergoing comprehensive chromosomal screening (CCS).
Women over 39 are faced with a dilemma: the likelihood of pregnancy per embryo transferred declines significantly due to a higher incidence of chromosomally abnormal embryos, and the need to transfer a higher number of embryos to compensate. Unfortunately, this results in significantly higher incidences of multiple pregnancies. However, the use of CCS is a means to avoid this problem.