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How To Determine The Date Of Conception?
Question: I had my period on January 10th it was due February 2nd I know this is a 23 day cycle so did I conceive 14 days before the 2nd or is my luethal phase shorter because my date of conception is January 25th but this could only be true if my cycle was 28 days? Is it likely I conceived around the 20th or 25th?
Brief Answer:
it could be
Detailed Answer:
Hello,
unfortunately the length of the cycle cannot be predicted and you only know it after the period comes. A normal period may vary in duration. 21 days is the shortest duration. A fetal ultrasound scan may estimate the age of the fetus, so this is the best way to know. The gynecologists usually use the date of the last menstruation to estimate the age of the fetus. That's - probably - why the day of conception was estimated to be the 25th of January.
I hope you find my comments helpful!
You can contact me again, if you'd like any clarification or further information.
Kind Regards!
it could be
Detailed Answer:
Hello,
unfortunately the length of the cycle cannot be predicted and you only know it after the period comes. A normal period may vary in duration. 21 days is the shortest duration. A fetal ultrasound scan may estimate the age of the fetus, so this is the best way to know. The gynecologists usually use the date of the last menstruation to estimate the age of the fetus. That's - probably - why the day of conception was estimated to be the 25th of January.
I hope you find my comments helpful!
You can contact me again, if you'd like any clarification or further information.
Kind Regards!
Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar
Right so if she based it off the first day of my period it could be off a few days since I dont have a 28 day cycle?
Brief Answer:
yes
Detailed Answer:
That's right. The ultrasound will probably detect the difference though.
yes
Detailed Answer:
That's right. The ultrasound will probably detect the difference though.
Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar
Well the ultrasound at 6 weeks and 4 days said January 25th but when I went back for my next one she said I was about a few days to a week further along than they thought. Which is why I think I'm right about ovulating around 20th.
I'm 26 and some odd days to 27 Weeks pregnant. If you could estimate when I might have conceived that would help alot with my confusion
I'm 26 and some odd days to 27 Weeks pregnant. If you could estimate when I might have conceived that would help alot with my confusion
Brief Answer:
ultrasound scan at the first trimester is the most accurate way
Detailed Answer:
I understand... It won't make a big difference - we're talking about a few days only - but the best estimation of the gestation age is an ultrasound scan in the first trimester (after the 7th week). Please take into account that any ultrasound scan depends on the operator's skill and that the findings are never 100% certain. For example, accurately measuring a structure as tiny as 10mm or even less may be required for the correct estimation.
There are certain features that can be detected and utilized to determine the age of gestation. A properly skilled gynecologist should be able to detect them. Keep in mind that a fetus growth rate may change during gestation.
So in conclusion, I can't say which of the dates is the correct one. You've got to trust the date that the first trimester ultrasound scan estimated.
Kind Regards!
ultrasound scan at the first trimester is the most accurate way
Detailed Answer:
I understand... It won't make a big difference - we're talking about a few days only - but the best estimation of the gestation age is an ultrasound scan in the first trimester (after the 7th week). Please take into account that any ultrasound scan depends on the operator's skill and that the findings are never 100% certain. For example, accurately measuring a structure as tiny as 10mm or even less may be required for the correct estimation.
There are certain features that can be detected and utilized to determine the age of gestation. A properly skilled gynecologist should be able to detect them. Keep in mind that a fetus growth rate may change during gestation.
So in conclusion, I can't say which of the dates is the correct one. You've got to trust the date that the first trimester ultrasound scan estimated.
Kind Regards!
Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar
Well the one I took after that had me at 14 weeks when I was supposed to be 12 and 6 days according to the first one. But that was before 7 weeks I know there's no way to know 100%. I guess my question is which one should I trust as since the second one on has been consistent every time?
Brief Answer:
the second one probably
Detailed Answer:
The estimation from the first ultrasound scan was probably based on the sac diameter which may provide results with 4-11 days inaccuracy. The next ultrasound scan likely detected the crown-rump length and/or biparietal diameter. Both of them are more accurate (3-8 days of inaccuracy).
So I would trust the second ultrasound more than the first, but you'd better accept your gynecologist's opinion. Your gynecologist is the best person to tell which is the most likely date.
Beyond the first trimester, the growth rate can become more variable, so the results are less trustworthy.
Best wishes for an uneventful pregnancy and delivery!
the second one probably
Detailed Answer:
The estimation from the first ultrasound scan was probably based on the sac diameter which may provide results with 4-11 days inaccuracy. The next ultrasound scan likely detected the crown-rump length and/or biparietal diameter. Both of them are more accurate (3-8 days of inaccuracy).
So I would trust the second ultrasound more than the first, but you'd better accept your gynecologist's opinion. Your gynecologist is the best person to tell which is the most likely date.
Beyond the first trimester, the growth rate can become more variable, so the results are less trustworthy.
Best wishes for an uneventful pregnancy and delivery!
Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar
Thank you and yes the first ultrasound was done at clinc. When I got to my actually doctor is when she said I was a little more further along. I'll trust that one. Just one more question. She didn't change the due date is it because the dates are so close anyway it would really play a factor?
Brief Answer:
I suppose she'll use the tests to estimate the best date for delivery
Detailed Answer:
You're welcome!
Although I'm not a gynecologist, I believe that the due date in this case is not that important for two reasons:
- it's very close to the other date
- the gynecologist may use tests (ultrasound scan, fetal heart monitoring) to determine the most appropriate date for delivery.
The date of delivery can be influenced by various factors, like medical problems you may have (like gestational diabetes for example) and luck of course! Your baby may decide that it wants to get out sooner than your gynecologist's calculations.
I hope I've addressed your concerns!
Kind Regards!
I suppose she'll use the tests to estimate the best date for delivery
Detailed Answer:
You're welcome!
Although I'm not a gynecologist, I believe that the due date in this case is not that important for two reasons:
- it's very close to the other date
- the gynecologist may use tests (ultrasound scan, fetal heart monitoring) to determine the most appropriate date for delivery.
The date of delivery can be influenced by various factors, like medical problems you may have (like gestational diabetes for example) and luck of course! Your baby may decide that it wants to get out sooner than your gynecologist's calculations.
I hope I've addressed your concerns!
Kind Regards!
Note: For further follow up on related General & Family Physician Click here.
Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar
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