The arrival of ultrasound, and especially of ultrasound in 4D, has allowed us to discover really curious things regarding the gestation process.
One of them is the call evanescent twin syndrome, also called missing twin syndrome.
It involves the loss of one or more fetuses during the early stages of pregnancy that, if they had followed their course normally and had developed with the other or other babies, would have been a twin brother. It is estimated that one in eight simple pregnancies (of a single baby) is really a multiple pregnancy in which a fetus ends up disappearing in the uterus.
In other words: maybe we had a twin brother gesturing at our side in the womb and perhaps our son or daughter had a twin brother at his side in the first weeks of gestation.
How do you discover
The first ultrasound is usually done by 10-14 weeks of pregnancy. However, there are women who control themselves earlier because they go to a private gynecologist or because they require more thorough pregnancy control.
In many ultrasounds performed in weeks 5-6, two or more embryos are observed and the mother is told to expect twins, triplets, etc. However, in subsequent ultrasounds, one of the fetuses has disappeared and, many mothers who were expecting twins, become Pregnant of only one baby.
Why one of the fetuses disappears
The truth is that it is unknown. The evanescent twin syndrome because it has been observed that it happens, but the cause is still uncertain. Some people think that it could be a natural defense mechanism against what would be a high-risk pregnancy rather than a complication or problem.
Where does the missing twin go?
The phenomenon of the missing twin usually happens in the first trimester of pregnancy, when the embryo is still very small. In most cases the twin that stops seeing each other is absorbed by the mother, by the placenta or even by the other brother, giving the feeling that it has disappeared.
Many times there is vaginal bleeding, such as a common abortion, but the other brother, who does progress, remains in the uterus.
Lefties could be a mirror twin
One of the theories that the evanescent twin syndrome is that left-handed people could be the result of a twin gestation in which the other twin has not developed.
After a few days of fertilization of the ovule, one of the two hemispheres of the brain becomes predominant, determining whether we will be left-handed or right-handed in addition to other characteristics.
The division of the ovule when twins are gestated is usually done before this phenomenon, however there are times when the ovule replicates once it has been determined what the dominant hemisphere will be and the resulting twin is a reflection of the first.
This phenomenon is called twins in mirror. If one is right-handed, the other is left-handed, if one has the heart to the left the other could even have it to the right, etc.
Having then twins in the mirror, if the right-handed man stopped evolving and disappeared the left-handed baby would be born as an only child. Hence the theory that left-handed people could really be twins in the mirror of a baby who never got pregnant.
Video
Here is an excerpt from the National Geographic documentary "In the womb: twins, triplets and quadruplets" that summarizes everything discussed. A really interesting video.
