Originally Posted by MaerynPearl
it does NOT run on the fathers side. fraternal twins are a maternal thing. Only the mother can have the risk of it because they hyperovulate (release more than one egg at a time) All men release millions of sperm per shot so their side means nothing.
The identical twins do not run in families at all, so you don't actually have an increased chance. Everyone in the world has the same risk of identical twins, they happen randomly when a fertilized zygote splits in two.
And at 18 weeks even with twins one would not be up in your ribs.
Well, that depends. If in my father's line there were fraternal twins, I would technically have a higher risk for them, since my father could pass on that gene to me.
However, unless the twining ran to the last common ancestor between you and your cousin, original poster, there's no way you could inherit it.
Identical twins, as has been mentioned, are a case of random mutation. It is not inheritable.
Fraternal twins are inheritable, but ONLY from a previous to you blood line. Meaning, if your great-grandma had twins, you have a higher 'risk'. If your cousin has twins, doesn't matter, because she could have gotten it from her side of the family that is unrelated to you.
As for u/s, it's difficult to miss a twin, unless it's an old crappy u/s machine. U/S pics up bones really clearly, and it's hard to miss 4 arms, kwim? However, if it's a fuzzy old machine, maybe, because it's harder to 'see' clearly.
As for your weight gain, relax! There's nothing you can do about it right now. In addition, you also have 2 young kids to run after! Not getting enough sleep increase weight gain in non-pregnant people, why not pregnant women too? Just focus on eating healthy, getting lots of fluid and regular movement. Pregnancy is a big hormonal deal, and your body has already gone through it twice. Maybe this time due to older age (4 years since first baby) and more responsibilities you gained a bit more.