Twins Run in Your Family “Do twins run in your family” is probably the second most common question asked to parents of multiples, right after “Are they twins????” The answer to the first question is, yes . . . and no.If you, your mother, or your mother’s mother is a fraternal (dizygotic) twin your chances of having twins increases significantly. The main reason for this is an inherited a gene for “hyperovulation” – you release more than one egg during an ovulation cycle, which increases your ability to conceive fraternal twins.Some experts also say that there is no correlation between Dad’s genetic background and the birth of twins. Other experts say that Dad may pass a ‘twin gene’ (the hyperovulation gene) from his side of the family to his daughter. Or the gene may be passed on to his son, who passes it on to HIS daughter – and so on.
Many experts also say identical (monozygotic) twins are not hereditary – identical twins are simply random by nature. Studies and research show that none of the ‘factors’ seen in increased twin births (fertility treatments, age, weight, hereditary, etc.) make any statistical difference in the chances of having identical twins. Many families with identical twins, however, beg to differ!