A question about twins......and genetics?

All the misinformation here!!! (Genetics questions really ought to go into "Biology" :-) )

Some bits of information:

- The only form of twinning that has any sort of genetic underpinning is fraternal twinning via hyperovulation. Indentical twinning, where the zygote splits after the 8-cell stage of the developing blastula owes itself to environmental pressures, not genes.

- There are various genes that have been discovered which affect hyperovulation. These genes reside on both somatic chromosomes and sex chormosomes (on the X chromosome). Your article you posted from about.com is *generally* correct, however their statement about the genes needing to come from a maternal lineage is absolutely false. The only way a genetic factor can be restricted to women is if the gene resides on the mtDNA. mtDNA regulates respiration in cells' mitochondria and has absolutely nothing to do with fertility. Even with the genes which reside on the X sex chromosome, one must remember that women (unlike men) receive one X chromosome from BOTH their mothers and fathers meaning that men CAN pass on hyperfertility genes to their daughters.

- I skimmed your ehow.com article. It sounds like complete pseudoscientific rubbish to be perfectly honest. Lots of old wives' tales mixed in with "alternative remedies" which have no clinical data to back up their claims. Take this for example: "an additional one woman out of 176 taking folic acid will bear twins as compared to women not taking the supplement." One out of 176 is a 0.57% increase. Considering that ANY GIVEN WOMAN REGARDLESS OF FAMILY HISTORY has roughly a 4% chance of twinning during a pregnancy, a 0.57% increase is NOT statistically significant (alpha =0.05, with the standard 12 degrees of freedom in clinical statistics).

- Having several other children over the age of 30 indeed increases your chances of twinning, but for the exact same reason why having children after the age of 30 increases your chances significantly of having children with Trisomy 21 (Down Syndrome). Both are due to massive non-disjunction of chromosomes during the second Anaphase of meiotic cellular division. I would NOT recommend exhausting this strategy for the sake of your children. Better to have one completely healthy child than two or three who will have a very diminished quality of life and of whom will require extensive resources to take care.

The woman who posted above is mistaken. You CAN get the gene from your father.

A woman CAN inherit the "hyper-ovulation gene" from either of her parents. However, if she inherits it from her father, the gene will appear to "skip a generation" because men cannot affect whether his partner's ovaries will release multiple eggs. Thus, a man with a family history of twins is not more likely to father twins himself. BUT, if a man has fraternal twins in his family, he can pass the twin gene on to a daughter who might go on to conceive twins herself.

So to answer your question....."the mother's side" means the mother who is pregnant......YOU!

But there's no way to know if the gene was passed to you by your father....unless you have fraternal twins! So you'll just have to wait and see. Will you get an ultrasound?

Interesting articles you posted. I found some other factors that increase your likelihood of conceiving twins:

1. Women with slightly higher fat percentages and those who are a little overweight are more likely to have twins.

2. The Yoruba tribe in West Africa has the highest rate of twinning in the world. A study concluded that the mother's diet was the cause, being high in cassava, a type of yam or sweet potato. The peelings of this vegetable are thought to contain a chemical that causes hyperovulation.

3. The more kids you have, the more likely you are to conceive twins in a subsequent pregnancy.

It's possible, but it's no guarantee. Fraternal twins run on my mother's side, including me, I have a twin brother, and my little brother and sister are also twins. I am now pregnant and was hoping for twins, especially boy-girl, but I am only having one:) So, while it's a possibility, I wouldn't get my hopes up:)

You know, I am not sure

Because I heard that it is supposed to run on the mothers side but there is new science that suggest its the man's sperm that causes the egg to split.

There are no twins on my side, but many on my husbands and my doctor did tell me my odds for having twins are increased.

We'll find out Sept 17th!

The Mother that is pregnant. You have a 3% chance of having twins anyway. If your mother or father was a twin you have a 6% chance. It's still really low.

Edit**

Fraternal twins (the only kind that are genetic) run on the mother's side...meaning you, your mom, your mom's sisters, your female cousins of your mom's sisters, your maternal grandmother, etc. They are only passed to daughters by their mothers. So you would not have an inclination to ovulate two eggs at a time. Your mother gives you the gene for that (since your dad can't, he doesn't have any genes for female stuff).

Hi fraternal twins are actually nothing to do with genetics, fraternals come from the mother releasing 2 eggs rather than the embryo splitting like identical twins do, realising two eggs is something that can happen to any woman, more common in older women.1 in 80 pregnancies are twins.

umm not sure it has to do with the semen and the egg hard to explain