Australian scientists make IVF breakthrough
AUSTRALIAN scientists have found the death rate of babies conceived using in-vitro fertilisation is significantly reduced when only one embryo is implanted.
A study of more than 50,000 births in Australia and New Zealand found the chance of a baby being stillborn or dying within a month of birth was 53 per cent higher when two embryos were transferred to the mother's uterus.
The study found the difference was more pronounced in births involving fresh – rather than frozen – embryos. Births involving two fresh embryos had a 74 per cent higher risk of perinatal mortality than births following fresh single transfers.
Michael Chapman, from the University of New South Wales, said the study supported other research which showed that babies born after single embryo transfer were "bigger, less premature and have lower abnormality rates".
"Compared with babies who were born after a double embryo transfer, the single embryo transfer babies fared much better in terms of birth weight, in terms of still birth, in terms of complications of pregnancy," Dr Chapman said.
The study leader, Elizabeth Sullivan, said the findings showed that Australia's policy of promoting single embryo implants had helped to reduce infant mortality
Countries such as the United States and the United Kingdom have rates of single embryo transfers of between 12 and 15 per cent, compared with 70 per cent in Australia.
"The number of embryos transferred per procedure is the major determinant of multiple pregnancy and multiple delivery, which contribute to an elevated risk of preterm birth and low birth weight," Professor Sullivan said.
"These are risks in addition to those already faced by women being treated for infertility."
Peter Illingworth, an IVF clinician who worked on the study, said the death rate among babies born after single embryo transfer was just a fraction above the rate of 10 per 1000 for all births.
The study was presented this week at a meeting of the European Society of Human Reproduction and Embryology in Turkey.