Thursday, January 31, 2008


While we were at the doctor yesterday, they measured a few different bone lengths to get an estimate of Emma's size and gestational age (GA). At our 7 week ultrasound, it seemed that she was behind schedule by about a week. This time she is ahead of schedule by 0.6 weeks. The measurements and the GA they correspond to are given below. She basically made up a week in a half in gestational age since the last ultrasound (hence the extra large post title). Before we get to the measurements, I'll tell you what they mean:

From a great site on ultrasounds and measurements:
BPD: Biparietal diameter (BPD) is the distance between the two sides of the head. This is best used early for age determination because different size babies can have different results in late pregnancy.
HC: Head circumference (HC) is the total length around the head. This a better determinate than BPD but is more difficult to accurately measure. Notice the HC is dead on the GA while the BPD is a little off.
AC: Abdominal cicumference (AC) is the circumference around the abdomen. This measurement is not very accurate for GA dating but is used to chart the baby's growth. This becomes especially important in late pregnancy to verify that the baby is growing and to estimate birth weight.
FL: Femur length (FL) is a measure of the of the longest bone in the body (the upper leg bone). This bone is used similar to BPD for age estimation and for length estimates.

Little Emma Ruth's measurements

measurement weeks size
BPD: 39 mm GA: 17.6
HC: 130 mm GA: 16.8
AC: 130 mm GA: 18.0
FL: 23 mm GA: 16.5

Composite from measurements: 17.4 weeks
Actual (at time of ultrasound): 16.8 weeks

Estimated weight: 201 grams (0 lbs. 7 oz.)

Her assessment is normal. Everything looks good and there is nothing unusual with her size. We just find it funny how she went from small to big between visits. All of the measurements above must be performed as early as feasibly possible for the best age determination. We will have a follow-up with an ultrasound in 5 weeks on March 5th at 2pm. This will be a visit to check the baby and the cyst to make sure everything is fine.

1 comment:

Lynn said...

i love Emma Ruth. I great name for a much loved little girl. congrats on a daughter. taie care