Yes, twins do seem to run in families. The cause is hyper-ovulation, a genetic trait to release more than one mature egg each month. This effect is only applicable to fraternal twins, as identical twins are not effected by genetics and every pregnancy carries the same chance of developing into identical twins.
The exception to this is older mothers. As we age the chance of having twins increases whether there are twins in the family or not.
A family history of twins doesn't make a male any more likely to have twins themselves. Men can pass the gene on to their children - it will only effect daughters, a male with the gene does not ovulate so his carrying the trait will have no effect on his wife.
Any twins in the family conceived with the aid of fertility drugs will not have an effect on the twin "gene".
no
Yes.
No, but it increases your chances of having a PLASTIC BABY.
No it will not.
Yes; having a STD absolutely does increase your chances of contracting HIV.
Having sex closer to ovulation could increase your chances of having a boy.
no
No, but if you have twins in your family there is a good chance of twins but soy stuff does not increase or decrease your chance of having twins.
Despite what you may have heard, taking prenatal vitamins won't increase your chances of getting pregnant, but it will certainly increase your chances of having a healthy baby once you are pregnant. See the Related Links section below for more information.
having lots of intercourse on yor fertile days
There is an increase in the chance of for instance, Downs syndrome as the mother gets older.
Yes, iced tea can increase your chances of getting cavities. This is because tea contains acids and tannins that can erode tooth enamel and lead to decay if consumed frequently and not offset by good oral hygiene practices.