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How Accurate Are Ultrasounds Done Within 6-7 Weeks Of Pregnancy?
Question: How accurate are 6-7 week ultrasounds. I went the day after I got 4 positive urine test they couldn't see anything but like a tiny tiny peanut they couldn't measure. They said it was to early. The estimated I was 2-3 weeks I went back 3 weeks later and I was 6 weeks and 4 days. Date of conception January 25th. I took the test February 2 or 3rd. I was thinking that would have been to early especially to get 4 positives with a 25miu urine test. The next one I took april 9th said I was 12 weeks 4 days. The doctor told me they measured wrong and i was closer to 14 weeks? They gave me another due date of October 8th. I was wonder is this normal could the original date of conception be wrong?
Brief Answer:
first trimester ultrasound date is reliable
Detailed Answer:
Hello dear,welcome to healthcare magic.I understand your concern.
In my opinion the ultrasound done within 12weeks ie.,first trimester is accurate of all ultrasounds.It gives the due date with a variability of 5 days.
The variation of 1week - 10 days between the dates calculated by last menstrual period and ultrasound is considered to be normal.
The abdominal ultrasound detects the gestational sac at 6 weeks and the same is detected by transvaginal ultrasound at 5 weeks.
So any date is given by a calculation and any given date is a probable date with varying accuracy.The due date give in first trimester ultrasound is more accurate and reliable.
Hope this satisfies your query.
Feel free to discuss furthur.
Best regards...Dr.srilatha
first trimester ultrasound date is reliable
Detailed Answer:
Hello dear,welcome to healthcare magic.I understand your concern.
In my opinion the ultrasound done within 12weeks ie.,first trimester is accurate of all ultrasounds.It gives the due date with a variability of 5 days.
The variation of 1week - 10 days between the dates calculated by last menstrual period and ultrasound is considered to be normal.
The abdominal ultrasound detects the gestational sac at 6 weeks and the same is detected by transvaginal ultrasound at 5 weeks.
So any date is given by a calculation and any given date is a probable date with varying accuracy.The due date give in first trimester ultrasound is more accurate and reliable.
Hope this satisfies your query.
Feel free to discuss furthur.
Best regards...Dr.srilatha
Above answer was peer-reviewed by :
Dr. Prasad
Thank you. Ever since I was closer to 14 weeks the dates have been consistent apparently I have 2 due dates 8th and 18th. I'm now 30-32 weeks. I'm on pase for my baby to be here from October5-15th. Do you still think date of conception is right? Is it normally for it to be off by a week at 6 weeks? I've been told that can often be to early to measure accurately as well.
Brief Answer:
need more information
Detailed Answer:
Hello dear,I got your query.I understand your concern.
In my opinion I want to know :-
1)In which ultrasound scans the due dates of 8th-18th,5th -15 th were given.
2)What was the due date given in first trimester scan?
3)Also give me your last menstrual period date by which we can calculate your due date.But for this your cycles need to be regular.
4)So how are your cycles usually?
5)The dates of intercourse before the missed period?
6)What do you mean by off by a week at 6 weeks?
Kindly provide me the information.
Looking forward to hear from you.
need more information
Detailed Answer:
Hello dear,I got your query.I understand your concern.
In my opinion I want to know :-
1)In which ultrasound scans the due dates of 8th-18th,5th -15 th were given.
2)What was the due date given in first trimester scan?
3)Also give me your last menstrual period date by which we can calculate your due date.But for this your cycles need to be regular.
4)So how are your cycles usually?
5)The dates of intercourse before the missed period?
6)What do you mean by off by a week at 6 weeks?
Kindly provide me the information.
Looking forward to hear from you.
Above answer was peer-reviewed by :
Dr. Vinay Bhardwaj
First due date at 6 weeks was October 18th. Period was January 11th. I took test on February 2nd so I ovulated early obviously. When I was 12 weeks doctor said I was closer to 14 weeks on April 9th and gave me a second due date of October 8th. I have history of irregular cycles.
Being closer to 14 weeks meaning when I measured 6 weeks 4 days I was closer to 7-8weeks doctor says I was anywhere from 3days to week and half further along than they thought maybe she saw more cause she said that when we did the 3D ultrasound and maybe that was more clear I kinda knew I was further along because I took the test because I knew I was pregnant I was started to bloat noticeably. To start bloating I would think your at least 4 weeks pregnant?
And that's when she said October 8th is my due date. Its not a big deal cause it falls into the 2 week window, maybe that's why she gave me 2 due dates insteaded of changing first one. I guess they don't change due date if its not a huge difference
Being closer to 14 weeks meaning when I measured 6 weeks 4 days I was closer to 7-8weeks doctor says I was anywhere from 3days to week and half further along than they thought maybe she saw more cause she said that when we did the 3D ultrasound and maybe that was more clear I kinda knew I was further along because I took the test because I knew I was pregnant I was started to bloat noticeably. To start bloating I would think your at least 4 weeks pregnant?
And that's when she said October 8th is my due date. Its not a big deal cause it falls into the 2 week window, maybe that's why she gave me 2 due dates insteaded of changing first one. I guess they don't change due date if its not a huge difference
Brief Answer:
First trimester scan is reliable
Detailed Answer:
Hello dear,thanks for the information.I understand your concern.
In my opinion as you have irregular cycles the due date obtained by considering the last menstrual period is not reliable.
As you have first scan done at 6 weeks the due date given in this ie.,october18th is more reliable than the later scan done at 14 weeks.
Its not a big deal as the variation is only 10 days.
Usually the due date is calculated where the 40 weeks of pregnancy is completed.
But the period from 37 to 41 weeks is called term.And delivery is considered normal if it occurs during this period and is not associated with any complications as the baby is mature enough to survive in external environment.
Less than 37 weeks is called preterm.
And after 41 weeks is called postterm.
As the both dates come between term period you need not worry.
If you are still doubtful the scan done at 36-37 weeks gives the estimated weight of the baby and placental maturity.If the placenta has reached grade 3 maturity then it is safe to deliver.
Observe the fetal movements daily.And lie down on sides preferably left to incease the blood supply to fetus.
Drink adequate fluids upto 3 litres to prevent urinary infections as they are routinely seen in pregnancy.
Hope this satisfies your query.
Feel free to discuss furthur.
Best regards....dr.srilatha
First trimester scan is reliable
Detailed Answer:
Hello dear,thanks for the information.I understand your concern.
In my opinion as you have irregular cycles the due date obtained by considering the last menstrual period is not reliable.
As you have first scan done at 6 weeks the due date given in this ie.,october18th is more reliable than the later scan done at 14 weeks.
Its not a big deal as the variation is only 10 days.
Usually the due date is calculated where the 40 weeks of pregnancy is completed.
But the period from 37 to 41 weeks is called term.And delivery is considered normal if it occurs during this period and is not associated with any complications as the baby is mature enough to survive in external environment.
Less than 37 weeks is called preterm.
And after 41 weeks is called postterm.
As the both dates come between term period you need not worry.
If you are still doubtful the scan done at 36-37 weeks gives the estimated weight of the baby and placental maturity.If the placenta has reached grade 3 maturity then it is safe to deliver.
Observe the fetal movements daily.And lie down on sides preferably left to incease the blood supply to fetus.
Drink adequate fluids upto 3 litres to prevent urinary infections as they are routinely seen in pregnancy.
Hope this satisfies your query.
Feel free to discuss furthur.
Best regards....dr.srilatha
Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar
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