Backstory: Our first daughter, Ainsleigh Brynn, was born with a "constellation" of heart defects that ultimately combined to kill her. There's about a 5% recurrence rate for congenital heart defects. That's not a lot, and there's little to be done about it in utero anyway. However, we live in a small town; our hospital doesn't have a NICU and the nearest pediatric cardiologist is at LeBonheur in Memphis. So, the thinking is: find out if there are any problems, so that we can be prepared --- where in this context "prepared" means, crucially, that we'd arrange to have the baby in Memphis at a hospital that can support the baby.
Our OB agreed with the fertility doc, and so referred us to a perinatologist in Memphis. We had that appointment yesterday, October 11th. It went very well.
The ultrasound itself lasted about an hour and a half. The tech told us baby is a girl first thing.
Then she checked out the baby in every dimension. For instance, she counted all the fingers and toes.
There were lots of other checks, too. She confirmed that baby has two umbilical arteries (this is the correct number; Ainsleigh only had one), that her kidneys are in place a supplied with blood (she can watch blood flow through the renal arteries), that her spine is properly formed, and more.
One thing they do is estimate the baby's size. The tech takes three measures: the circumference of the head, the circumference of the abdomen, and the length of the femur. Each measurement is used to form an independent estimate of baby's weight. These estimates are averaged; the average comes to 10 oz. This figure is looked up on a chart ; it corresponds to the average size of a baby at a gestational age of 19 weeks. Given that baby was 18 weeks 5 days at the time of the ultrasound, she's right on time.
In addition to the 2-D images taken at a particular depth, they can rapidly scan through depths and use the computer to construct a 3-D portrait of baby:
It's imperfect, of course, but you can see her pretty well here.
As to the purpose of the visit: her heart looks great. They spend a great deal of time on this. There are a number of techniques involved. A simple ultrasound can show the heart moving as it beats, and the valves opening and closing. The machine can also detect the movement of blood through the major blood vessels as well as between the chambers of the hearts. Finally, they can zero in on and listen to the various components of the heartbeat: this or that valve opening and closing in rhythm. The amount of detail that can be gleaned is really impressive, given baby's heart is about the size of a quarter.
Put all these approaches together and you get the result you want: baby is healthy, and her heart is in perfect working order.
