My previous post was a celebration of the five millionth IVF baby born some time this summer. The numbers of babies born thanks to ARTs treatments has been calculated by a team of experts who track IVF and ICSI transfers and births. Traditionally, multiple embryos were transferred in a single IVF cycle, with the idea that the percentage of healthy live births would increase due to the likelihood that one (or more) of the three embryos would take. However, new evidence is proving that theory wrong.

The Australian and New Zealand Assisted Reproduction Technology Database contains over 50,000 births, recorded between 2004 and 2008. The data from this database was analyzed, focusing on the number of embryos transferred in a cycle vs. the percentage of perinatal deaths.

Perinatal death has been defined by different criteria, but the most widely accepted is the death of a fetus, after twenty weeks of gestation. In some definitions, it does not include fetus prior to 27 weeks. The World Health Organization defines it as “The number of stillbirths and deaths within the first week of life after birth per 1000 births.”

The results show that single embryo transfer (SET) provides the lowest percentage of perinatal death. There were 13.2 deaths per 1000 births in the single embryo transfer group, with 19.1 deaths per 1000 births within the double embryo transfer. Additionally, the number of deaths was also higher in fresh transfers as opposed to frozen transfers (74% higher).

Twins also had a much higher perinatal death rate: 27.4 per 1000 births (and natural twins that resulted from a single egg had an even higher rate than the twins created by two embryo transfers.)

If you are considering IVF, discuss these results with your reproductive specialist. As new information like this becomes available, it may be advisable to revise standard protocol: SET may become the recommended procedure.

- Lee