Classically, the bigger twin is the more physically dominant. It's basic human nature, and particularly applicable to boys as they hit puberty. It happens often with singleton siblings too… the older is bigger and enforces him/herself through physical dominance.
Twins often exchange dominance throughout their lives, and in that sense may alternate between birth order categories. Aside from inherent personality traits, the impact of birth order in multiples is likely more often one of perception rather than reality, especially in light of recent studies.
For example, one twin can be physically and verbally dominant while the other twin can be psychologically dominant. But in some cases, one twin can be dominant in all three areas. This needs serious attention as it can affect both the twins in a long run.
Every twin parent will agree that a set of twins, albeit identical or fraternal, will have a dominant and a submissive child.
Most often, fetuses known in utero as twin A are also first born and thus retain their label. However, this is not always the case, such that the twin A newborn was previously labeled twin B in utero and vice versa.
Such twins, known scientifically as 'MoMo', an abbreviation for monoamniotic-monochorionic, are some of the rarest types of twins, making up less than one percent of all births in the United States, noted the statement. It also stressed that such MoMo twin pregnancies have a high risk of fetal complications.
Knowing which twin is the older one is usually a no-brainer. The time of birth is recorded, and whichever one is born first is officially the eldest.
Identical (i.e., monozygotic, or MZ) twins share 100 percent of their genes, whereas fraternal (i.e., dizygotic, or DZ) twins generally share only 50 percent of their genes.
Identical twins are almost always the same sex, although there are some rare exceptions to this rule. Because identical twins occur when a single fertilized egg splits and forms two embryos, each embryo has the same chromosomes (usually, XX for girls or XY for boys). Remember that sex and gender are not the same.
Dizygotic (DZ) twins, also called fraternal twins, occur when two egg cells are each fertilized by a different sperm cell in the same menstrual cycle. DZ twins are about twice as common as MZ twins, and they are much more likely to run in families.
The mode of delivery depends on the position of the babies when in labour. If the first twin (leading twin) is coming head first, it is possible to try for a vaginal delivery. However, if the first twin is in a breech position (bottom down), a Caesarean section is usually recommended as it would be the safest option.
The developed, functional twin is medically known as the autositic or dominant twin, while the underdeveloped one is simply referred to as the parasitic twin. The dominant twin is usually healthy in most aspects but may have extra tissue, organs, or limbs from the parasitic conjoined twin.
“Twin studies of major depressive disorder have showed that if one twin has the illness, a fraternal twin has an increased likelihood of developing the disorder and an identical twin's likelihood is even higher,” says Dr. Avari.
Yes, it's both normal and common for this to happen. It can take time to get to know your babies, and to bond with both of them. It's natural if bonding happens more quickly with one baby than the other. It doesn't necessarily mean you love one twin any more or any less than his sibling.
Will you tell them who is older, be it by one minute or one hour or more? On the rare chance that your twins are born on different days… well, the choice is already made for you. There is no right or wrong answer, it's a personal preference.
Raising one child is difficult enough and changes your life forever. But raising twins can be even more overwhelming. While having two babies brings unique challenges, it can also bring twice the amount of joy.
Still, she cautions, a lot more work needs to be done to establish a causal link. Fraternal twins, in which each of two eggs is fertilized by a different sperm cell, occur in about four of every 1000 births. About half of those result in male-female twin pairs.
Because identical twins come from the exact same combination of egg and sperm, they have exactly the same combination of chromosomes. A DNA test would reveal that they have over 99.9% identical DNA.
There are twins who say they have felt each other's pain. And their close relationship and nearly-identical physical structure means there could be a sliver of truth in the theory — as pain can be psychological and can be felt empathetically.
The quick answer to this question is that, in a twin pregnancy, it is the mother's genes that determine twins. First up, giving birth to identical twins is not genetic, but conceiving fraternal twins is. The mother may have the genetic trait of releasing two eggs in one menstrual cycle.
Genetics can definitely play a role in having fraternal twins. For example, a woman that has a sibling that is a fraternal twin is 2.5 times more likely to have twins than average! However, for a given pregnancy, only the mother's genetics matter.
There is one particular power though which twins possess, longevity. Fraternal twins live longer than singletons and identical twins longer still. Male identical twins on average, saw the most benefit. The rarity of twins has inspired many myths about them.
On September 1, sisters Umeno Sumiyama and Koume Kodama turned 107 years and 300 days old, officially breaking the record for the world's oldest living identical twins. The Japanese siblings are also the oldest identical twins to have ever lived.