
How To Determine The Date Of Conception And Due Date Using Ultrasound Scan?

Question: Hi doc
I had my ultrasound done on July 3, which say 8 week 1 day old. My first date of my last menstrual period is April 24, 2015.
I am at a 35 day cycle and always start ovulated on the 17th day, being May 10, in this case!.
1) does the 8 week 1 day old per ultrasound meaning "gestational age" or " fetal age"?
The technician does not specify and only reply that there is a chart to compute the date of conception.
2) per my blood test did on XXXXXXX 9, I was told that I was at my 4thweek. So my doc was very confirmed that I must have conceived in the week of May 10-16.
3) with the above info, what would be by due date and conception date?
I had my ultrasound done on July 3, which say 8 week 1 day old. My first date of my last menstrual period is April 24, 2015.
I am at a 35 day cycle and always start ovulated on the 17th day, being May 10, in this case!.
1) does the 8 week 1 day old per ultrasound meaning "gestational age" or " fetal age"?
The technician does not specify and only reply that there is a chart to compute the date of conception.
2) per my blood test did on XXXXXXX 9, I was told that I was at my 4thweek. So my doc was very confirmed that I must have conceived in the week of May 10-16.
3) with the above info, what would be by due date and conception date?
Brief Answer:
we can't determine the exact date of ovulation
Detailed Answer:
Hi dear and thanks for trusting to us.
As per your report, I'm glad to say you that your pregnancy is good.
Pregnancy age in 8 weeks is calculated from CRL (crown rump length of embryo) not from gestational sacus.
If your blood beta HCG level on XXXXXXX 4 show that your pregnancy age was approximately 4 weeks, and the last ultrasound scan on 3 July show that your pregnancy age is 8 weeks,hence your conception date is after 10 May.
But we can't determine the exact time of your conception time.
All the best
we can't determine the exact date of ovulation
Detailed Answer:
Hi dear and thanks for trusting to us.
As per your report, I'm glad to say you that your pregnancy is good.
Pregnancy age in 8 weeks is calculated from CRL (crown rump length of embryo) not from gestational sacus.
If your blood beta HCG level on XXXXXXX 4 show that your pregnancy age was approximately 4 weeks, and the last ultrasound scan on 3 July show that your pregnancy age is 8 weeks,hence your conception date is after 10 May.
But we can't determine the exact time of your conception time.
All the best
Above answer was peer-reviewed by :
Dr. Raju A.T


Thank you doc.
However, I recalled that the techician mentioned that my due date is feb 11, 2016. Would that change my conception date?
However, I recalled that the techician mentioned that my due date is feb 11, 2016. Would that change my conception date?
Brief Answer:
No it can't change your conception date
Detailed Answer:
Hi dear again.
End due date is determined by ultrasound scan, hence conception date can't be change.
If your due date is on February than conception time is after 10 May.
Best regards
No it can't change your conception date
Detailed Answer:
Hi dear again.
End due date is determined by ultrasound scan, hence conception date can't be change.
If your due date is on February than conception time is after 10 May.
Best regards
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Above answer was peer-reviewed by :
Dr. Prasad

Answered by

Dr. Vjollce Mbiarra
OBGYN, Maternal and Fetal Medicine
Practicing since :2006
Answered : 1572 Questions
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