Understanding Twin Family History: Maternal Lineage & More

Question
What is considered family history of twins?  I though it had to be maternal family but I didn't know who on the mother's side counts. (oh, I am a few months away from 30 ;) and this is our first baby.  First try, first preg) My husband had twins on his side so at Thanksgiving (the day I found out I was pregnant (early...just missed my period and a pos. result on a HPT) my husband was joking about twins.  I told him it had to be on the mother's side when my grandmother piped up and said that her cousin and her grandmother had twins.  Now just curious about chances. Does this count or is it too far down the family line? thank you

Answer
Identical twins have no relationship to family history. HOwever, there is a higher incidence of fraternal twins in relatives of women who had twin births. It does not matter if it is on the mother's side or the father's side. Monozygotic twins (identical) are the result of the division of a single fertilized ovum. Dizygotic twins  (fraternal) are produced from separately fertilized ova. Although monozygotism is random (it does nmot fit any discernible genetic pattern) dizygotism has heridary determinants.There is a high incidence of twins in women who already had twins in a previous pregnancy. HOwever, if you have twins in your family or in your husband's family, it merely increases the chances but the percentage has not been documented. It is a bit too early to tell if you are carrying a twin pregnancy at this time. YOu should get a sonogram at  around 20 weeks gestation, which will be accurate in the number of fetuses. Good luck.