Question 1

is an efw via ultrasound of 3lb 9-10oz large for a 30w3d fetus? how accurate is this weight? edd was confirmed by multiple early ultrasounds.

Accepted Answer

Fairly accurate: The weight estimate could be off by as much as 10%. At a little over 30 weeks, the fetal weight should be around 3 lbs. Three pounds 10 ounces is bigger than average. Find out from your doctor what the percentile is.  Is not abnormal unless the estimated weight is more than 90%.

Question 2

can you tell me how precise are ultrasounds about fetal weight?

Accepted Answer

See below. : They are pretty accurate. Any variations will be due to operator dependence, how accurately measurements were taken and position of the fetus. Measurement/weight charts were developed over many years, by several different studies, all showing some degree of difference. Although not 100% dead on, ultrasound determination of weight should be considered as the most accurate guesstimate.

Question 3

when you subtract 2 weeks from the ga provided by an ultrasound, does that give you the estimated fertilisation age or the estimated fetal age?

Accepted Answer

Yes: When estimating gestational age by using an ultrasound scan, 2 weeks are added to the fetal age (the fetal age is the fertilisation age).

Question 4

i had my ultrasound today and my ob said the fetus is too small to measure. now i'm worried that the fetus has no heart beat. im estimated 5/6 weeks?

Accepted Answer

Normal: The heartbeat doesnt occur until 12 weeks gestation. So if you are estimated at 5 or six weeks, that is within normals. A safe and healthy pregnancy wish to you

Question 5

hi, 
i am 34 weeks pregnant. my previous ultrasounds were normal but yesterday doctor said that fetus is now in lower limit of average for weight i.e ?

Accepted Answer

Talk to your dr: Please discuss with your obgyn.  Typically when a baby is measuring small, your doctor will schedule follow up testing including more ultrasounds and sometimes monitoring of the baby's heart rate.  Sometimes this can be normal (the baby is just small) and sometimes it is because the placenta isn't working like it should so we watch the baby carefully

Question 6

can 13 week fetus be mistaken in ultrasound as a 9 week fetus?

Accepted Answer

NO not in my office: Either your dates are off or there is something wrong with the pregnancy, at 13 weeks the margin of error is 5-6 days at the most either way.

Question 7

is there a clear difference between an 8 week 9 week and a 10 week fetus on ultrasound? or can a 8 week fetus be mistaken for a 10 week fetus?

Accepted Answer

Sonographer skill: It is fairly easy to get an accurate fetal measurement at this gestational age. Generally there is a 3-5 day margin of error on fetal measurements at this gestational age. A skilled sonographer would be able able to accurately measure the fetus

Question 8

9 week ultrasound showed 2 sacs with fetus a 2.7 crl with hb and fetus b 1.5 crl with no hb at 7 weeks 2 days, what r chances of vts and chimera?

Accepted Answer

VTS: At this early gestation, the embryo without a heartbeat will gradually go away. Since there are 2 sacs, there is little risk to the healthy fetus.

Question 9

can a 9 week fetus possibly grow slow and measure at time of ultrasound at 7 weeks? and be normal?

Accepted Answer

Yes: Yes, usually dating can be a bit off.  Important to continue following to demonstrate continued growth along the normal curve with continued normal cardiac activity. Good luck!

Question 10

when i had my transvginal ultrasound at 6 weeks the fetus had heartbeat but at 9 weeks the heartbeat was gone. what could be the cause?

Accepted Answer

Genetic abnormality: You had an early fetal demise. This is fairly common and most often its a chromosomal (gene) abnormality during early development that is responsible.

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Doctor answers about:

Ultrasound estimate of fetal weight more than 9 pounds

A member asked:

Is an efw via ultrasound of 3lb 9-10oz large for a 30w3d fetus? how accurate is this weight? edd was confirmed by multiple early ultrasounds.

A member asked:

Can you tell me how precise are ultrasounds about fetal weight?

A member asked:

When you subtract 2 weeks from the ga provided by an ultrasound, does that give you the estimated fertilisation age or the estimated fetal age?

A member asked:

I had my ultrasound today and my ob said the fetus is too small to measure. now i'm worried that the fetus has no heart beat. im estimated 5/6 weeks?

A member asked:

Hi, i am 34 weeks pregnant. my previous ultrasounds were normal but yesterday doctor said that fetus is now in lower limit of average for weight i.e ?

A member asked:

Can 13 week fetus be mistaken in ultrasound as a 9 week fetus?

A member asked:

Is there a clear difference between an 8 week 9 week and a 10 week fetus on ultrasound? or can a 8 week fetus be mistaken for a 10 week fetus?

A member asked:

9 week ultrasound showed 2 sacs with fetus a 2.7 crl with hb and fetus b 1.5 crl with no hb at 7 weeks 2 days, what r chances of vts and chimera?

A member asked:

Can a 9 week fetus possibly grow slow and measure at time of ultrasound at 7 weeks? and be normal?

A member asked:

When i had my transvginal ultrasound at 6 weeks the fetus had heartbeat but at 9 weeks the heartbeat was gone. what could be the cause?

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