If you are lucky enough to come from a family with a pattern of having twins then genetically you are more likely to as well. So if you, your mother or your maternal grandmother are or were fraternal (non-identical) twins then your chances of having twins may increase to as many as 1 in 7.
While men can carry the gene and pass it on to their daughters, a family history of twins doesn't make them any more likely to have twins themselves. 3 But, if a father passes on the "twin gene" to his daughter, then she may have a higher chance than normal of having fraternal twins.
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.
This belief is based on the assumption that twinning is genetic and runs in families. However, if that was truly the case—if there was a twin gene—then twins would occur with predictable frequency in those families that carry the gene. There is no concrete scientific evidence that suggests twins skip a generation.
Factors that increase the chance of twins include: consuming high amounts of dairy foods, being over the age of 30, and conceiving while breastfeeding. Many fertility drugs including Clomid, Gonal-F, and Follistim also increase the odds of a twin pregnancy.
You're 35 or older
As you age, your chance of conceiving twins increases. Researchers have found that women over 35 produce more follicle stimulating hormone (FSH) than younger women, which may cause more than one egg to drop at ovulation.
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.
Race – African-American women are more likely to have twins than any other race. Asian and Native Americans have the lowest twinning rates. Caucasian women, especially those over age 35, have the highest rate of higher-order multiple births (triplets or more).
When both eggs are fertilized, the resulting siblings are fraternal twins. Because this gene can be passed on, the tendency to have fraternal twins can in fact run in families. Identical twins, on the other hand, result from one fertilized egg randomly splitting in two, creating two siblings with identical DNA.
Yes, some types of twins run in families. Non-identical (fraternal) twins tend to be hereditary. Some people inherit a gene that causes more than one egg to be released during ovulation, increasing the likelihood of multiples being conceived. This can make for lots of twins down the generations!
However, few genes appear to be definitively linked to hyperovulation, so it could just be that genetics in general on the mother's side contribute to the probability of having fraternal twins. Heredity on the father's side, on the other hand, does not increase a couple's odds of having twins.
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 (also called monozygotic twins) result from the fertilization of a single egg by a single sperm, with the fertilized egg then splitting into two. Identical twins share the same genomes and are always of the same sex.
A twin pregnancy can often be detected in your first trimester by an ultrasound Opens a new window at 6 weeks or later. If your healthcare provider checks your hcG levels, a higher-than-normal level can be a sign of a twin pregnancy. But you'll need an ultrasound to confirm that it's really twins.
In the United States, twins account for about 3 percent of live births.
Benin and the cluster of countries nearby is an area that has been spotlighted many times before for what appear to be staggeringly high rates of twins. Just east of Benin, the westernmost regions of Nigeria have some of the highest twin rates in the world.
There are several theories for why this happens: (1) Cell repulsion hypothesis: Developmental differences between adjoining cells might cause repulsion, leading the fertilized egg or zygote to divide; (2) Co-dominant axes: Two embryonic axes form and develop, possibly causing the fertilized egg to split; and (3) ...
Australians Anna and Lucy DeCinque call themselves the “most identical twins in the world”, and work to live up to their self-proclaimed title. They're engaged to the same man, have the same bathroom schedule, and work the same job – one for a salary the other as a volunteer, for legal reasons.
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.
Researchers analysed records from more than 100 countries and found a substantial rise in twin birthrates since the 1980s, with one in 42 people now born a twin, equivalent to 1.6 million children a year. According to the study, the global twin birthrate has risen by one-third, on average, over the past 40 years.
The birth process is similar to giving birth to a single baby. If you're planning a vaginal birth, your health team may recommend that you have an epidural for pain relief.
A little more than half of twin pregnancies end in preterm delivery (before 37 weeks). While 40 weeks is the full gestation period of the average pregnancy, most twin pregnancies are delivered at approximately 36 weeks (range 32-38 weeks depending on the type of twin pregnancy).
Age: The older you are, the higher your chances of having fraternal twins or higher order multiples. One theory is women age 35 or older produce more follicle-stimulating hormone (FSH) than younger women.
Barring pregnancies that result from assisted reproductive technology, dizygotic twins are far more common than monozygotic twins and account for 70 percent of all twin gestations.