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Real-life Wonder Twins

By: Daniele Souza

Photo: Renee D

Photo: Renee D'Avila

Have you ever heard of the Wonder Twins, superheroes that were famous in the 1980s? The two twin siblings were originally from another planet and had special powers, which they activated when they joined hands. But twins do not come from another planet: there are many of them throughout the world.

In real life, twins are two or more siblings that were born in the same birth. They may or may not look the same. In the cartoon, the twins were dizygotic (fraternal or nonidentical) twins. That's because there was a brother and a sister, that is, they are of different genders, which means they were formed by two different egg cells.

Types of twins

In a normal pregnancy, the mother's egg is fertilized by the father's sperm and the embryo develops in the mother's uterus, where it is fed by the placenta (the organ that establishes the communication between the blood circulation in the fetus and in the mother). In the case of fraternal twins, this process takes place more than once in the same pregnancy, which means that fraternal twins are the result of the fertilization of different eggs by different sperm cells. These eggs will produce twin siblings that can be of the same gender or different genders, with different placentas. These siblings may or may not have similarities, because they are just like other brothers and sisters that are not twins. The only difference is that they shared the same pregnancy.

Oliver e James Phelps. Foto: Niccolô Caranti

Oliver e James Phelps. Foto: Niccolô Caranti

The birth of identical or monozygotic twins are even more curious. These twins are always of the same gender, because they originated from a single egg (fertilized by one sperm), which divided into two or more embryos. Therefore, identical twins have the same genome. In most cases, identical twins share a single placenta, which can cause more complications, because they have to share the nutrients they need for their development and their blood circulation are connected.

There are also the siamese or conjoined twins, which are also formed by one fertilized egg. However, in this case, the twins are connected by some part of the body. That can happen either because of the incomplete division of the fertilized egg or the afterwards union of the identical twins during the pregnancy. Such twins can be conjoined at the head, the abdomen or other parts of the body. Conjoined twins are rare and they share the same placenta.

Some twins brothers and sisters are famous, such as Oliver and James Phelps (Fred and George Weasley, from the Harry Potter series), Bia and Bianca Feres (Brazilian synchronized swimming athletes), Brazilian cartoonists Chico and Paulo Caruso and graffiti artists Otávio and Gustavo Pandolfo. Singers Alanis Morissette and Elvis Presley; actors Kiefer Sutherland, Scarlet Johansson and Ashton Kutcher; and the model Gisele Bündchen are some of the celebrities that have twin brothers or sisters.

Assisted reproduction

When women need to go through treatment to get pregnant, often three or four embryos are implanted to assure the treatment is successful: that is because the embryos do not always develop naturally. However, in many cases, more than one of them become viable, which produces dizygotic twins.

Special attention

A twin pregnancy requires special attention from both the doctor and the woman, because of its particularities. For example, only rarely does the mother reach the expected 40 weeks of pregnancy, because the uterus can only distend to a certain extent: the more babies, the more premature the birth can be. Plus, the babies also increase the mother's blood volume and nutritional needs. The pressure over joints, bones and muscles is much greater. A greater level of medical care is recommended in twin pregnancies, with more regular visits to the doctors and examinations.

See also:

How to tell identical twins apart?

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