The transfer of one pre-screened embryo during IVF leads to birth rates equivalent to transferring two unscreened embryos, indicates new research from the USA.

Preliminary results presented at the American College of Obstetricians and Gynecologists Annual Clinical Meeting revealed that single embryo transfer combined with preimplantation genetic screening (PGS) resulted in fewer twin pregnancies and better health outcomes for both mother and child.

'Single embryo transfer with comprehensive chromosome screening has the potential to be paradigm-shifting and revolutionary in the world of IVF', explained lead researcher Dr Eric Forman, of Reproductive Medicine Associates of New Jersey (RMANJ) at the Robert Wood Johnson Medical School. 'Patients can do single embryo transfer and maintain excellent delivery rates while not taking on the treatment-related risk of multiples', he added.

Infertility treatment currently accounts for 18 percent of twin deliveries in the USA. However, multiple pregnancies carry increased health risks to the mother and child.

In the study 175 women aged 43 or younger received either a single pre-screened chromosomally normal embryo or two unscreened embryos. Results so far indicate equivalent pregnancy rates in the two groups. No twins resulted from single embryo transfers whereas 53 percent of double embryo transfers led to multiple pregnancies.

At present only ten percent of women in the USA opt for an elective single embryo transfer. Dr Forman noted that most women choose to have multiple embryos transferred because they feel that this improves their chances of becoming pregnant. However, as more people become aware of the success rates of single embryo transfer, its popularity as a treatment option may increase.

'The technology exists today to make single embryo transfer the standard of care across age groups, eliminating the vast majority of complications stemming from IVF, while maintaining excellent delivery rates for couples who have struggled with infertility', explained Dr Forman.

PGS adds an extra cost to fertility treatment in the USA and research is ongoing at RMANJ to establish whether in the USA this cost is offset by the reduced healthcare burden associated with lower risk singleton pregnancies.

Reproduced from BioNews with permission, a web- and email-based source of news, information and comment on assisted reproduction and human genetics, published by Progress Educational Trust.