According to this article, the earliest recorded set of twins was recorded about 7,000 to 8,000 years ago, so twins have obviously been around for a long time. But according to BabyCenter.com, the rate at which twins are born increased by 76% between the years of 1980 and 2009. The rate of other multiples, such as triplets, quadruplets, etc., has also increased greatly since 1980. There has definitely been no crazy multiple-making contraption invented… at least yet. So what is causing the rise in the amount of multiples being born?
Women used to regularly have children in their teenage years, but that has become a rarity. Women now tend to wait until their 20’s or even their 30’s to have kids. This is the first reason for an increase in multiples because according to an article by Nicholas Bakalar, as women age they tend to release more than one egg per cycle. If more than one egg is fertilized, it results in more babies. Women 30 years or older gave birth to 35 percent of 2009’s twins, which was a 20 percent increase from 1980. The higher average age of women only accounts for about one third of the rise in multiples, though. The biggest reason that the birth rate of multiples has shot up is because of fertility treatment, which is any method or procedure that increases a woman’s chances of conceiving by stimulating the ovaries and causing women to release more than one egg at a time. In vitro fertilization (IVF), a process by which a woman’s egg(s) is/are removed from her body and fertilized by sperm in a laboratory and then put back into her, is one of the most popular types of fertility treatment and according to BabyCenter.com, it has given women anywhere from an 8.8 percent to a 29.1 percent chance of conceiving multiples.
It’s definitely not by chance that multiples have become so common today. We have science and technology to thank for all of these extra cute babies. Without the constant work and discovery in those areas, fertility treatments such as IVF would not exist today and we would not have near as many multiples.
This is how in vitro fertilization works.
In high school, I took a developmental psych class and we covered in vitro fertilization in depth and the high risk of giving birth to multiples. The famous TV couple Kate & Jon Gosselin from Jon and Kate plus 8 gave birth to both twins then sextuplets with in vitro methods. A possible theory for the rise in twins is the higher usage of these methods. Women are having children later, and with age, comes more difficulty getting pregnant. With more women using in vitro, the number of multiples is rising drastically. I researched the possibility of genetic link of twins running in families.
The Twin Gene