Twins - Staten Island,NY

Identical twins do not have to run in the family. This happens when one egg decides to split into two!

Fraternal twins do tend to run in families. Identical twins have absolutely NO genetic connection whatsoever. You can have both kinds of twins even if twins does not run in your family.

Logically, genetically speaking it must be the mother's side of the family because the cause of fraternal twins is the release of two eggs in a cycle as opposed to the usual one egg. Right? That is just my assumption, but makes sense to me.

I wouldn't say they have to "run in the family", I mean it has to start or pick up somewhere. So, even if or just because you don't know of twins in your family that doesn't mean that you have no chance of it happening.

Fraternal twins without fertility treatments are hereditary. "Identical" twins have not yet been found to be hereditary so for now they say "identical" twins aren't hereditary. I often hear that frat twins skip a generation, but I don't believe that because I come from a family of "twinners". My grandma had twins-- my mom and her fraternal twin sister Plus my grandma's older sister (my great-aunt) had twins and one of those twins had twins. So that right there debunks the skipping a generation thing. I also have twins --I don't yet know if mine are fraternal or "identical". Oh, and it used to be that the chance of twins was also more likely to occur based on the mother's "race" and age, but now fertility treatments are also a factor.
There's more to this, but I don' want this to be much longer.

********* http://en.wikipedia.org/wiki/Twin *************

Has your sister had a sono yet. That will more than likely solve all questions. Also, my sister had twins and she started showing way early, but it was also her third prego. I work with a girl that is in her 2nd trimester with twins. Shes very thin and we didnt even know she was prego till she was like 12 weeks along. So you never can tell. You sister could just be very bloated.

The answer is no, twins dont really "run" in families. Its just something that happens. I have twins. It was just something that happened. My husbands brother also has twins, but they used fertility treatments that made the odds of having twins ( or more) much greater. There are no twins on my side of the family at all. There are no twins on my husbands side either.

you dont have to have twins in the family to have twins. For it to be more likely, you have to have twins on your moms side, and fraternal are more common or likely to run in the family. I have 8 month old twin boys, I have identical twin aunts, and my great great aunt had 3 sets of boy/girl twins. I am the only one of the "cousins" who had twins. I think mine are because of being on 2 different very strong antibiotics during the time I conceived, mine are fraternal boys.

other factors are age, if you have already had twins, being on antibiotics makes you ovulate and if on BC antibiotics render them innefective.

Twins don't have to run in a family to "happen". My husband is a twin and he has twin cousins. We have no twins in my family but my sister had twin girls! The doctors told us that twins are "more likely" during the first month post- Birth Control Pill b/c your body is regulating... guess when my sister got preggers? My husband and nieces are all fraternal twins... two eggs released and fertilized at the same time. Identicals? Really rare and considered a genetic anomaly!

I'm really tiny so I showed super early with both of my pregnancies.
I think she'll just have to wait for an ultrasound to see what's what.
I have a friend who had identical twin girls and there were no incidents of twins on either side as far back as any documented generation.
If twins are a common occurance in a family, then it's always a possibility, but she won't know for sure without testing.