Each year, couples from all over the world spend thousands upon thousands just to be able to conceive a child. Because in vitro fertilization (IVF) offers a chance for childless couples to become parents, fertility specialists have been carefully studying factors involved in the procedure to boost success rates.
A more recent study, though, published in the medical journal Lancet, goes further to show that women in general should not have more than two embryos implanted into their uterus, as those with three or more embryos don’t necessarily have a higher chance of getting pregnant, and instead have a higher chance of delivering preterm.
In most countries in Western Europe, the general rule is one embryo transfer for women 37 years old and below, and only up to two embryos for women between 37 and 40 years old, while older women can get up to a maximum of three embryo transfers.
Scientists have discovered, though, that while implanting three or more embryos may result in more multiple births, these generally end up causing more problems for the mother and the babies. There is a higher risk for twins to be born prematurely and to be low in birth weight, making them prone to abnormalities.
Researchers studied 124,000 IVF cycles resulting in 33,000 live births from January 2003 to December 2007. The number of multiple births and preterm babies were compared for those women aged 40 and above to those 40 and below.