For OB ultrasounds, there are some indications of whether it is appropriate to do one and when it is not. Most people would tend to believe that, “Well, it's a pregnant patient. We need to do dating for the pregnancy. We do this on all of our patients. And so, pay me.” But there are in fact documents out there produced by people like the American College of Radiology or ARUM or ACOG that say, “Here are the protocols for doing these.”
Appropriateness of OB Ultrasound In Pregnancy
Now, ACR has produced what they call “appropriateness” criteria. And some of these have been adopted by payers. So, you need to know of their existence.
For OB, they have written documents on first trimester bleeding, growth disturbances, multiple gestations, premature cervical dilatation and second and third trimester bleeding. As time goes on, they will probably add some more. But you need to know what the payer is looking at in order to ensure that you're going to get paid correctly.
On the ACOG side, there is the ultrasonography in pregnancy. All of the organizations out there have given a blanket statement on when it is appropriate to do an OB ultrasound scan. ACR and AIUM basically say perform only when there is a valid medical reason. As we know in pregnancy, ante-natal screening can also be considered a valid medical reason.
And ACOG says it's for specific indications in low-risk pregnancy and for all high-risk pregnancies. Most payers out there will have taken a look at these and have adopted them.
Measurements In Pregnancy Ultrasound
Now, some of the measurements that are available for the ultrasounds that are being performed, the first one is the gestational sac, which is usually measured only in early pregnancy. What this will give you is - by looking at the gestational sac, it will estimate the gestational age which is an important factor for later on in the pregnancy to know whether or not the patient is going in perhaps to early labor whether or not she is in prolonged labor and things like this and whether or not intervention is required.
The crown-rump length is another measurement that is taken. This is one of the best measures to date the embryo. And there is a formula that is used by the software in order to calculate this.
The biparietal diameter, that's the transverse width of the head at its widest point. Growth retardation maybe a problem if it shows an abnormal BPD. For instance, sometimes, it can be due to non-nutritional conditions. It could be a genetic condition. It could be some damage to the fetus due to an infection. But this measure is best done after 12 weeks to get an accurate measurement.
Head circumference is another thing they look at. What they're looking for are variations in the head shape. And this will tell you again something else about the fetus whether or not they are growing correctly.
Femur length, this is a measurement that confirms the measurement of the head because the length is not usually affected by nutritional growth retardation. And this measurement normally is done best after 14 weeks.
The abdominal circumference, again, there are some ways to measure that and formula for it. Then there is a head circumference and the abdominal circumference ratio. This is again another indicator of nutritional growth retardation or an indicator of diabetic macrosomia. So, all of these measures that are taking place are going to be very important in an assessment of how well the baby is doing in utero and whether or not interventions are going to be required down the road.