CANBERRA, Feb. 25 (Xinhua) -- Twins conceived via in-vitro fertilization (IVF) are four times more likely to suffer from congenital heart problems, according to an Australian study.
Michael Davies from the University of Adelaide collaborated with peers from Canada to examine the incidence of heart problems in twins from assisted pregnancies.
IVF, a process whereby an egg is fertilized with sperm outside the body then implanted in a uterus, can greatly increase the chance of having twins.
"We have previously shown that having a baby as a result of using assisted procedures such as IVF nearly doubles the chance that a baby will have heart problems," Davies said in a statement.
"This risk appears to double again for twins compared to singletons. Identifying the excess risk associated with having twins through IVF is important, as it is preventable," he said.
Approximately 15 out of every 1,000 babies in Australia are born with congenital heart defects, which can cause disability or even death in the first year of life.
The most common defects are narrowing arteries and underdevelopment of the heart.
However, the rate of twins being born in Australia as a result of IVF remains relatively low at 4 percent compared to 20 percent in North America.
"Multiple embryo transfer very slightly improves the chance of pregnancy but can increase the chances of twins being born by 10 times," Davies said.
Davies and his peers from Canada have used their findings to call for a limit on the number of embryos transferred during IVF.
"This has reached epidemic levels in many countries including North America because of the cost of treatment," Davies said.
