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khagihara, OB/GYN (Doctor)
Category: OB GYN
Satisfied Customers: 6590
Experience:  Trained in OB & GYN for many years.
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Can ultrasounds really determine conception dates? I had a

Customer Question

Can ultrasounds really determine conception dates? I had a girl i slept with on march 30th and now she is pregnant. She also slept with a few other people after me. She had an ultrasound on june 7th,2016 and the baby CRL measured to be 2.03cm, how far along is she and how accurate is the measurement as it relates to gestational age?Is the ultrasound more accurate than the last missed period because there are more guys involved than one? what is the margin of error here in days? If she conceived by me march 30th that would put her at gestational age at 11.6 weeks on june 7th during her first ultrasound, instead she got a CRL measurement of 2.03cm and was told she was 8 weeks 5 days along. Can there be that much error in the ultrasound if sperm lives 5 days that i could be the father? she did take plan b the day after and she admitted sleeping with two guys after me unprotected.SO MY SPERM DIED APRIL 4TH, SAY SHE CONCEIVED APRIL 19TH, BECAUSE THE FIRST DAY OF HER LAST PERIOD WAS APRIL 5TH. THUS, THIS MEANS WITH THE PLUS MINUS OF 7 DAYS of errror ON THE ULTRASOUND THIS WOULD DATE THE CONCEPTION WINDOW TO APRIL 12TH TO APRIL 26TH, MY SPERM DIED ON APRIL 4-5TH. is THERE STILL any POSSIBILITY the child is mine?can the ultrasound at 8 weeks be off by two weeks or would there be a clear distinction on CRL. LASTLY, THERE WOULD BE A CLEAR DISTINCTION BETWEEN WEEK 8.5 AND WEEK 11 ON ULTRASOUND correct?Do all babies grow at the same rate in the first trimester and if there is a three week gestational age difference
Can you help me through this?assuming the sperm lives 5 days mine died on april 4th.
Submitted: 1 year ago.
Category: OB GYN
Expert:  khagihara replied 1 year ago.

CRL measurement with ultrasound is most accurate. We change the pregnancy date with the measurements.

Customer: replied 1 year ago.
can i email you a copy of the ultrasound, im still a little concerned because there is only an 8 day buffer between the day my sperm died and her gestational age.
Expert:  khagihara replied 1 year ago.

What do you mean by a copy of the ultrasound?

Customer: replied 1 year ago.
I mean a photo copy of the ultrasound by email
Customer: replied 1 year ago.
can you answer the rest of the questions in the question
Expert:  khagihara replied 1 year ago.

You can attach the copy here.

Customer: replied 1 year ago.
attached does this look accurate for a gestational age of 8 weeks 5 days
Expert:  khagihara replied 1 year ago.

I don't think it seems to be accurate. You should ask her to take another picture or go with her to take another picture.

Customer: replied 1 year ago.
what does not seem accurate about it. i saw it in person? can there be a variation of more than 7 days on ultrasound in the first trimester
Expert:  khagihara replied 1 year ago.

The head and rump are not clear to measure CRL (Crown Rump Length). The CRL should be measured again.

Customer: replied 1 year ago.
here is one done a week later at 9 weeks 4 days, . from the characteristics this does not look like a baby that would be at 11.5 weeks correct
Expert:  khagihara replied 1 year ago.

That's better. The head is on the left and rump on the right. Did they measure the CRL? If so, how many weeks and days with the ultrasound?

Customer: replied 1 year ago.
on this particular one they gave it a 9 week 4 day gestational age which is would be accurate with the the previous image. the CRL doesnt show on this particular image but they put a gestational age on it of 9.4 weeks
Expert:  khagihara replied 1 year ago.

In the picture, they didn't measure the CRL. Did they took another picture to measure it?