conception date from ultrasound

[joscadje]

On 8/11/2015, the gestational age was 19w1d. On 8/19/2015, the gestational age was 19w4d. The mother swears she didn't realize she was pregnant until July. She did not have any prenatal care until these two ultrasounds. How accurate is the due date if it is only calculated using these two ultrasounds as a baseline?  The doctor estimated the due date between 12/30/15-1/4/15 based on the first ultrasound. I am already concerned that over an eight day period, there was only 3 days of measurable growth. Thank you.

[AnnieBrooke]

She, the 14-year old, not she, Miley Cyrus.  

[AnnieBrooke]

I wish young girls felt that way also, but the place they learn how to be a female human being is popular culture... which presents and rewards young women who offer the world sex.  Miley Cyrus is even seen as empowered for all her public disrobing and sexual display.  She must feel that if she can't proudly point to her family and (presumably) gets no thrill from school or her achievements there, at least she has a body.

I think all you can do, if nobody in her family will agree that she should do a DNA test beforehand, is get a certified lab test for paternity after the baby arrives.  No drugstore tests, do it by court order if necessary.

[joscadje]

Thank you for your time. I agree. While my son made an enormous error in judgement, I really wish young girls realized they have so much more to offer this world than sex. It is very sad. The varying week counts were shown on the two consecutive ultrasound pictures she sent. The gestational age and the ultrasound date are shown on both, as well as the name of the doctor office.

According to the state we live in, a court order cannot be made to do a DNA test until after the baby is born. She has already been hospitalized once. Now, she is dating a 19 year old boy who probably also has no idea how young she really is. I almost hope the baby is my son's child just so we can help shield this baby from all the chaos he is going to see in his life.

Thank you again for the information. I greatly appreciate it.  

[AnnieBrooke]

If the ultrasound had been done in her sixth or seventh week, the dates you're giving would make it pretty clear that your son is the dad.  But by the time someone is in her 19th week, the margin for error could be a week or ten days if trying to use an ultrasound to determine conception, putting the first guy back into the ring and probably the third guy also.  This is even more true because she is getting varying "weeks" counts from her doctor.  (Was this by her report or were you there?)  I'm afraid all you can do, short of getting her to do a prenatal DNA test either by persuading her or by court order, is to test when the baby is born.  I'm sorry, for you, your son, and mostly for her.  Incidentally, when her last period came is really not material, since many people don't ovulate like clockwork.  

[joscadje]

Her mother is the one who said no. She said she knows her daughter is correct. The girl had sex with boy A on 4/6/15 (and possibly before that as well). She had sex with boy B (my son) on 4/12/15 and 4/18/15. She said she had sex with boy C on 4/23/15 and then through sometime in June. I know there is a chance. I am just trying to figure out how accurate her due date based on the ultrasound. The girl is clueless and says she doesn't know when her last period is. Her mother is a heroin addict with a police record for drugs. Sadly, it is just a hot mess all the way around.

[AnnieBrooke]

Do her parents want her to have a prenatal DNA test?  I'm having trouble determining why a 14-year-old has full say about testing, since she is a minor.  Does she or your son know exactly when they had sex?

[joscadje]

She had sex with 3 boys in a 4 week period. She told another boy she had a miscarriage in March. I knew there was a potentially larger window using the 19th week as a due date estimation. I offered to pay for the prenatal paternity test and was told absolutely not because she just knows this is my son's baby. I am just trying to be prepared. I guess the paternity test after the baby is born will tell us what we need to know.

[AnnieBrooke]

Are you asking if the baby's health might be at risk or mostly trying to find out if the dates point to your son?  As far as I know, her youth would not cause slow growth of the fetus.  The fact that the doctor gave a couple of different estimates rather close together does not really mean that much, since there is a pretty wide margin for error in the 19th week (it would be plus or minus ten days by now).  Why does she feel it is your son's baby, did she not have sex with anyone else near to the time she was having sex with him?

[joscadje]

The first estimated due due she was given was 12/30/15 based off the ultrasound done on 8/11/2015. She had NO prenatal care up to that point. She did not even take a pregnancy test until late July. My other concern is that she is only 14 years old. Could she be further along and the baby just be experiencing slow growth due to lack of prenatal care and her age?

[AnnieBrooke]

By the 19th week, it is not reliable, to use an ultrasound to try to determine when conception was.  I don't know why the two ultrasounds don't agree.  What was the very first estimated due date she was given, and when was she given that date?  (I.e., in July?)

[joscadje]

Both ultrasounds were done at the same office by the same doctor. The mother had sex with 3 different boys over a 5 week period, one of them being my son. The mother insists the baby belongs to my son. I am not saying he is not the father. I am just looking for the validity of the due date based on these two ultrasounds. Ultimately, the only thing that matters is that the baby is healthy but the lack of growth over an 8 day period is also concerning me.  

[AnnieBrooke]

Were  both ultrasounds done at the same place and read by the same doctor, or was one done at the ER and one at an ob-gyn's office?   That could easily explain the difference.