How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask khagihara Your Own Question
khagihara, OB/GYN (Doctor)
Category: OB GYN
Satisfied Customers: 6590
Experience:  Trained in OB & GYN for many years.
Type Your OB GYN Question Here...
khagihara is online now
A new question is answered every 9 seconds

I asked a question back in December about paternity. I'm

Customer Question

Hello - I asked a question back in December about paternity. I'm still concerned even though the doc before answered my question. Maybe I am just being paranoid or just need reassurance....
Submitted: 1 year ago.
Category: OB GYN
Expert:  khagihara replied 1 year ago.

What is your question? I will try to help you.

Customer: replied 1 year ago.
My last menstrual period was 7/5/15. I took an over-the-counter pregnancy test on 8/14/15 and it was positive. I also had an ultrasound done on 8/20/15 and they said I was around 6 weeks pregnant. I had sex with a guy (who I do not believe to be the father) on 8/8/15. But thinking about it, I believe I was ALREADY pregnant when I had sex with the guy. In addition, I asked a doctor before, and he says the heartbeat would not have been visible on ultrasound on 8/20/15 if it was in fact from the 8/8 encounter. I am now 36/4 days pregnant and am highly stressed because I just cannot tell my boyfriend, especially if its HIGHLY unlikely that it is the other man's baby. I would do a DNA test after she is born if my boyfriend has any concerns. The 8/8 encounter guy is Hispanic, I am white and my partner is white. I am terribly scared that the baby will come out looking Hispanic and I just cannot do that to him if that was really possible.... Im so sorry for the life story. Any help would be appreciated. Thank you.
Expert:  khagihara replied 1 year ago.

That means you conceived around July 31. The accuracy of the ultrasound is plus minus 7 days. It is unlikely the baby is the Hispanic guy's baby. Reassured.

Customer: replied 1 year ago.
While I understand that it is "unlikely" ... even my OBGYN said it would be "highly unlikely", what would you say the % of it being the Hispanic guy's baby would be?
Expert:  khagihara replied 1 year ago.


Customer: replied 1 year ago.
I was already pregnant when I had sex on 8/8? I'm sorry. I just don't know why my obgyn wouldn't tell me not to worry about it? Maybe he's just trying to cover his butt just in case.... It would be unnecessary to tell my boyfriend to get a paternity test if it's not possible? Plus, considering the baby is only a few... or a couple weeks away.
Expert:  khagihara replied 1 year ago.

Also your doctor's saying about the heartbeats is correct. You don't need to worry about it. Reassured.

Customer: replied 1 year ago.
Is there prenatal paternity testing I can do before she is born?
Customer: replied 1 year ago.
How did you figure the July 31 date?
Expert:  khagihara replied 1 year ago.

You can use a prenatal paternity test with your blood.

Customer: replied 1 year ago.
Ok. How did you figure the July 31 date?
Expert:  khagihara replied 1 year ago.

The conception occurs pregnant weeks minus 2 weeks before. So in your case, the conception occurred 4 weeks before 8/20/15. Sorry the conception date is July 23 from the calculaton. But your doctor should have done ultrasound and you were 36 weeks 4 days on March 16. The accuracy is plus minus 3 days. You conceived 34 weeks 4 days ago. Your conception date is July 18 plus minus 3 days. It is between July 15 and July 21. Even though the accuracy is plus minus 7 days, it is between July 11 and July 25. It is impossible the hispanic guy is your baby's father.

Customer: replied 1 year ago.
I see. I know you answered my question. Just a thought - If I had a genetic test done at like 13 weeks and my significant other did about a month later.... couldn't they just confirm paternity based upon comparing our blood types? I mean, I guess my question is .... does the genetic testing (for birth defects, i.e. down syndrome, other genetic disorders) give you the baby's blood type? Can they confirm based upon that?
Expert:  khagihara replied 1 year ago.

It is not blood type but DNA. Parentage testing uses tandemly repeated DNA length polymorphisms to compare DNA samples between individuals. It takes long time to explain about the DNA test to you.

Expert:  khagihara replied 1 year ago.

Sorry correction. It is DNA test after birth. Cell-free fetal DNA isolated from the plasma of the mother’s blood is analyzed using a dense microarray chip that examines 317,000 genetic markers known as single nucleotide polymorphisms (SNPs). An informatics algorithm is used to compute the similarity of genetic markers between the fetal DNA and the alleged father’s DNA, as well as to unrelated random individuals. It costs $1625 in the United States.

Related OB GYN Questions