So my mom checked the family Bible and said my great great grandfather Bingham had a twin brother. We don't know if they were identical or fraternal twins. I've read up on the genetics of conceiving twins though, and have concluded that this incidence of twins has no genetic correlation to my twin conception.
Here's a good article on
"Identical or Fraternal Twins" for reference (and a much better explanation than I'll be offering below):
http://www.twin-pregnancy-and-beyond.com/identical-twins-or-fraternal-twins.htmlSo there is no genetic marker for conceiving identical twins. So if my great great grandfather was an identical twin, it would have absolutely no influence on my conceiving twins at all.
For fraternal twins, there is a chance they could be genetic. There is a hyper ovulation gene that can be passed down on the X-chromosome. Hyper ovulation results in fraternal twins -- because two eggs (or more) are released by the mother during a cycle. This explains why the gene can't be passed on the Y-chromosome (since that's a distinctly male chromosome).
And a refresher from biology: Females are XX, and Males are XY.
Now if we consider that my great great grandfather
could have been a fraternal twin, that means his mother released two eggs that were simultaneously fertilized. Now if his mother released two eggs because she had a hyper ovulation gene -- then there is a good possibility that she could have passed this gene onto her son through her X-chromosome (remember boys get their X-chromosone from mom, and the Y-chormosome from dad). The genetic connection for me though, ends here, because my great great grandfather fathered a son, who in turn fathered my grandmother -- then follows my mom, and now, me. Making any sense? Well since the genetic marker for fraternal twins can ONLY be carried on the X-chromosome, my grandmother's father would NOT have inherited his father's X-chromosome, only his Y-chromosome. My grandmother's father would have instead inherited his X-chromosome from his own mother (who did not have twins). Therefore, my grandmother (as well as my mother and I) have no X-chromosome from the great great great grandmother who produced twins. If it's too confusing, refer to that article I linked to.
The whole XY deal of it all should also explain why Richard's genetic history plays no part in our conceiving twins either.
So what it all boils down to is that no matter what kind of twins I have, fraternal or identical, neither of them will be genetic for me -- unless of course I'm a mutant. hehehehe.
On a side note... I called my OB's office to schedule my next appointment -- which is Monday, March 8 (16 weeks). About two hours later I get a call from my OB's office, it's the nurse practitioner (the one I had seen at my belated 12-week appointment), she says, "Hello Ann! I just reviewed your chart over the weekend and saw the results of your ultrasound report!! Very exciting!" She was definitely as surprised as me. We talked about how we only heard the one heartbeat and everything. She said the report shows that the babies are 100% healthy and doing great! I told her I had just scheduled the follow up for next week. She explained that I'll be having a lot more appointments and ultrasounds than a singleton pregnancy, of which the ultrasound technician had already informed me. At anyrate, I had been wondering when the doctor's office was going to get the ultrasound results and if they were going to call me. So I'm glad she finally did. Richard and I calculated the time since I had the ultrasound and really, if you don't count the two weekends, it's only been 5 business days. So anyway, she said to come loaded with questions, and we already have a bunch ready!