Nowadays, this phenomenon increases, mainly because more and more women take some kind of fertility drugs, or apply the assisted reproductive technology in order to get pregnant. Any of these treatments increases chances of every woman to get pregnant with two or more babies at one time.
According to the statistics, at present about one in 32 deliveries is the twin delivery. This rate has become 65% more since 1980, and it is more than double the rate among those women, who are able to get pregnant without any medical assistance provided – here it is one in 89.
The situation is even more dramatic with the triplets and quadruplets. Between the years of 1980 and 1998, the rate of three and more babies, delivered at one time shot up by more than 400%, however, it is crept back down during the last several years, because most fertility medicines and treatments have been more refined. In the year 2003, one in 535 deliveries resulted in triplets, quadruplets, and more babies per time.
At the same time, the likelihood of having identical twins, or twins, who develop from the same egg, divided in two, is approximately one in 250 – 255. This rate stays constant all over the world for decades.
How likely are you to have more than one baby, if you are undergoing fertility treatment?
Most fertility medicines work by stimulating your ovaries produce and release more than one egg at the same time. On average about 35% of women, taking any kind of fertility medicine, have a chance to get pregnant with twins, triplets or more babies.
While undergoing the procedure of IVF (in vitro fertilization), your chances to become a mother of more than one baby are about 20 – 40%. Actually, everything depends on how many embryos were placed into your uterus. There are several other fertility techniques, like GIFT (gamete intrafallopian transfer) and ZIFT (zygote intrafallopian transfer), which also rise your chances to get pregnant with more than one baby at a time.
However, there is one kind of fertility treatment, which does not increase your chances to get pregnant with twins, triplets, or more babies. It is the IUI (intrauterine insemination) procedure, during which the male’s sperm is being injected into the female’s uterus with some special syringe. Although, most women, who have the IUI procedure conducted, also take some kind of fertility medicines in addition to it.
What are the other factors, which may influence your chances to have more than one baby at one time?
As a rule identical babies’ arrival occurs by sheer chance, however there are several factors, which may influence the appearance of fraternal twins. These are the following factors:
in case if you are a twin, or if your mom, dad, grandma, granddad, any of your cousins or any other relative of yours have or have ever had twins in their families, the chance of your having a set of your own twins increases slightly. Moreover, according to the statistics, women, who are fraternal twins, have a one out of 60 chance of delivering twins by themselves.
more twins arrive in the families of Afro – Americans, and less of them do in the families of Hispanics or Asians.
some recently conducted investigations prove that the older the pregnant woman is, the more chance she has to deliver fraternal twins, triplets, quadruplets, etc. Most scientists consider it to be so, because of the follicle stimulating hormone (FSH), which women begin to produce, when they become over than 35 years old. However, as the level of this hormone production increases, the woman’s fertility goes down; however FSH is also called the hormone, which makes the egg to get ripen in their preparing to the ovulation process every month. Thus, women, who have more FSH in their organisms, are less likely to release more than one egg during their single cycle. Ironically it is, but the older a woman becomes, the less likely she is to get pregnant, however if she manages to conceive, she is more likely to deliver twins or more babies at a time.
Number of pregnancies:
everything is easy: the more babies the woman has delivered (or, at least the more times she got pregnant), the greater her chance of having twins.
History of twins:
in case if a woman has already delivered or was pregnant with a set of fraternal twins, she is two times as likely to get pregnant with one more set of twins in the future.
it is curious, but twins are more common to arrive in large and tall woman, rather than in small and thin ones.