USA: in vitro fertilization responsible for 1 million twins

Since 1915 â€" when the birth data began to be tracked in the United States-until 1980, one in every 50 babies born had a twin, which corresponded to a rate of 2%.

Subsequently, the rate began to increase: in 1995 was 2.5%. In 2001, exceeded the 3% and in 2010 reached 3.3%. Currently, one out of every 30 babies born has a twin. The rate corresponds to many additional twins since 1980, but how many?

When the American Diseases Control Center calculated the number in 2009, concluded that there were 865 thousand twins. The calculations were redone with the data available until 2012 and it was concluded that there are 1,009,337 twins more than in 1980.

A few years ago, researchers from the Center for disease control analysed the phenomenon. Multiple pregnancies have an unfavorable impact on the main indicators of perinatal health, as the rates of premature births and underweight, "concluded the researchers, means the Quartz. Given the findings, the researchers wanted to know what was causing the increase in the birth of twins.

Enter the various conclusions that they reached with a deeper inquiry was that older women tend to have more twins than younger women and children in General. This demographic phenomenon was responsible for a third of the increase in the twins.

Researchers attributed the remaining increase to fertility treatments, especially in vitro fertilization and drugs that stimulate ovulation. The increase in the rate of births of twins seems to be, however, to stabilize. This is due in part to changes in the procedures of assisted reproductive technologies.

For example, the number of embryos implanted in the IVF process has a direct correlation with the number of multiple births. Thus, deploy two or more embryos increases the likelihood of at least one succeed and develop. However, it also increases the risk of multiple pregnancies. Previously, the number of embryos implanted was superior â€" what stimulated the increase of births of twins.

Foto: RiyAdh â€" M! s$/Creative Commons

If You Enjoyed This, Take 5 Seconds To Share It

• Facebook
• Twitter
• Google+
• StumbleUpon
• Digg
• Delicious
• LinkedIn
• Reddit
• Technorati