assisted reproduction treatment

The end goal of infertility treatment is pretty simple: to have a healthy baby. And while the prospect of having twins may seem attractive, that reality is that a multiple gestation greatly increases the risk to both the mom and babies.

Why are the issues of transferring 2 or more embryos quite common when planning pregnancy?

Usually this is because the pair go a long way to this decision, they often have not 1 or 2 attempts behind their backs, but much more. Also, artificial insemination programs are quite expensive. Therefore, to increase the chance of pregnancy, patients are asked to transfer 2 embryos but they do not realize that it can be a risk to their health.

Naturally, twins occur in about one in 250 pregnancies, triplets in about one in 10,000 pregnancies, and quadruplets in about one in 700,000 pregnancies. The main factor that increases your chances of having a multiple pregnancy is the use of infertility treatment, but there are other factors. 

Your race, age, heredity, or history of prior pregnancy does not increase your chance of having identical twins but does increase your chance of having fraternal twins. Infertility treatment increases your risk of having twins, both identical and fraternal. 

The duration of a normal singleton pregnancy ranges from 37 weeks to 42 weeks from the time of the last menstrual period. Twin pregnancies occasionally progress to 40 weeks but almost always deliver early. As the number of fetuses increases, the expected duration of the pregnancy decreases. The average duration is 35 weeks for twins, 33 weeks for triplets, and 30 weeks for quadruplets.

Conception happens when a sperm fertilizes an egg to form an embryo. However, if there are two eggs present in the womb at the time of fertilization or the fertilized egg splits into two separate embryos, a woman can become pregnant with twins.

 

• Identical twins: This type of pregnancy happens when a fertilized egg splits into two separate embryos. These embryos are monozygotic, which means that they have identical genes. Identical twins are the same sex as each other and look very alike.

• Nonidentical, or fraternal, twins: This type of pregnancy occurs when there are two eggs present in the womb at the time of fertilization, and sperm fertilize both of them. These embryos are dizygotic, which means that they do not have identical genes and may not be the same sex.

Fraternal twins are common after fertility treatment because healthcare professionals often place two fertilized embryos into a woman’s womb to increase the chances of a successful pregnancy.

Drugs are also a part of IVF. But one of the main factors that increases your chances of twins with this reproductive technology is the number of embryos you decide to transfer. Some couples choose to transfer just one. While the single embryo might split and turn into identical twins, this isn’t too likely.

The more likely scenario is with regard to fraternal twins. If you transfer two (or more) embryos and they both successfully implant and develop, twins (or more!) are on the way.

The rate of twin pregnancies with IVF with fresh embryos is 12.1 percentTrusted Source for women under age 35 and 9.1 percentTrusted Source for women ages 35 to 37. The chances decrease with age (unlike natural twin conception), as women 38 to 40 only have a 5.3 percentTrusted Source rate of twins. And for those who are 43 and older, the rate is just 0.5 percentTrusted Source.

And consider this: Some couples may choose to transfer two embryos during IVF. Say one of those embryos splits and then all three implant in the uterus. The result would be triplets — two identical twins and one fraternal sibling.