It was once believed that identical (monozygotic or MZ) twins occured at random. There is now some evidence to suggest that MZ twins may run in families, but this is very rare.
A family history of identical twins will not necessarily increase your chances of having them yourself, although the offspring of male identical twins are more likely to have them. However, you are more likely to have twins if there are fraternal twins in your family.
Since identical twins share the same DNA, the children of two pairs of identical twins are legally cousins, but genetically more similar to siblings.
number of previous pregnancies – the greater the number of pregnancies a woman has already had, the higher her likelihood of conceiving twins. heredity – a woman is more likely to conceive fraternal twins if she is a fraternal twin, has already had fraternal twins, or has siblings who are fraternal twins.
A dad who's one of a twin may inherit the gene, but it won't increase his chances of having twins too, because the gene only affects ovulation.
If the twins are present on your husband's/partner's side, it won't influence your chances of having twins. Remember, the gene for hyperovulation is only a factor for the mother. If your mother (or your grandmother or aunt) was or had fraternal twins, you might have the gene.
The answer is yes, but only in cases in which they're fraternal, as identical twins form from a single egg/sperm combination and thus cannot have different fathers.
Dizygotic twins are the most common type and are known as fraternal twins. Two-thirds of all sets of twins are dizygotic. When two eggs are fertilized during the same pregnancy, the result is a set of dizygotic twins. They are fertilized by two different sperm.
Fraternal twins are the most common type of twins, accounting for around two thirds of all twin pregnancies. Fraternal twins are the most common type of twins, formed when two eggs are fertilised by two separate sperm.
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.
Monoamniotic-monochorionic Twins
This is the rarest type of twin, and it means a riskier pregnancy as the babies can get tangled in their own umbilical cords. If you have monoamniotic-monochorionic twins, your healthcare provider will monitor your pregnancy closely.
Twins (non-identical) can be born at completely different times, sometimes even years apart.
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).
However, for a given pregnancy, only the mother's genetics matter. Fraternal twins happen when two eggs are simultaneously fertilized instead of just one. A father's genes can't make a woman release two eggs. It sounds like fraternal twins do indeed run in your family!
In Australia, twins happen in 1 in every 80 births. This means that 1 in 40 Australians is a twin. The birth rate of identical twins is the same around the world and doesn't vary with the mother's age.
Everyone has the same chance of having identical twins: about 1 in 250. Identical twins do not run in families. But there are some factors that make having non-identical twins more likely: non-identical twins are more common in some ethnic groups, with the highest rate among Nigerians and the lowest among Japanese.
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.
A pregnancy with fraternal twins has the lowest risk of all multiple pregnancies. This is because each baby has its own placenta and amniotic sac. You will sometimes hear fraternal twins referred to as 'dizygotic' twins.
As such, the mother of twins is given special treatment and is called Naloongo.
For the most part, twins and multiples share the same birthday. However, depending on the time of day the babies are born and how long the timespan is between each baby's birth, twins can be born on different days.
They come from the same fertilized egg and share the same genetic blueprint. To a standard DNA test, they are indistinguishable. But any forensics expert will tell you that there is at least one surefire way to tell them apart: identical twins do not have matching fingerprints.