Let me show you on this picture. You see this picture? This is a picture of the baby’s head. Well, there’s some little cystic structures in the baby’s head called choroid plexus cysts. And I’ll talk about that in just a second. Here’s a little spot where there’s extra fluid in the kidneys. Here’s a place where there’s a bright white spot in the baby’s heart called an intracardiac echogenic focus. These little things are associated with chromosome problems, as I said. But most people who have these things, most babies who have them, are actually normal. But it goes something like this. Let’s say the phone rings. ”Hey, it’s Dr. Fausett. You had your ultrasound this week and as you know we took a good look at the baby. And everything looked great except, except…” Right, you’re expecting the shoe to fall. “Yeah, everything looked really good except there’s this part of the baby’s brain that’s called choroid plexus and it secretes the fluid around the baby’s brain and spinal cord. Well, the baby had in that choroid plexus some little cysts. And these little cysts are just little fluid-filled collections and they go away. They don’t hurt the baby at all. I’m telling you about them because rarely babies who have those little cysts have another problem, a serious chromosome problem called Trisomy 18.”
And if babies have Trisomy 18, it’s really bad. They don’t do well. They often times don’t survive the pregnancy. They don’t do well after birth. They often don’t go home. So it’s a bad situation. Again, this is an uncommon problem but what happens if you get the phone call? The baby otherwise looks totally normal and so I think the chances that the baby has Trisomy 18 are really small, but because we found these cysts it increases the risk a little bit.
Now I want to show you that really and truly most babies who have these minor markers are normal. So let’s go through a little math here for just a second. Let’s say we had 10,000 pregnancies okay? And let’s say that the chances for Down syndrome is about one in thousand. It’s a little higher than that, but we use this is obstetrician math so if I have 10,000 pregnancies and one out of a thousand have Down syndrome, how many babies do I have with Down syndrome out of the 10,000? Ten. All right. Easy math, right? So we have 10. Now let’s say that 10 percent of babies with Down syndrome have one of those bright light spots in there heart. Okay, as an example. So now how many babies do I have out of the 10,000 who also have Down syndrome and who have a bright spot in their heart? One. One. We’re all the way down to one, right? Good. Now, how many pregnancies do we have out of the 10,000 who don’t have Down syndrome? This is higher math guys. You know it’s a factor here. All right. 9,990. Right? And let‘s say two percent of normal babies have bright white spots in their heart. So how many normal babies do I have that have bright white spots? This is division. Not very many. It’s 200. It’s two percent of 10,000, okay? So what I’m saying here is if the baby has a bright white spot, does the baby probably have Down syndrome, or probably not? Probably not. Probably not, right? I mean 200 to one in this case. But yet one out of 200 is more than one out of a 1000. Remember the background Down syndrome risk is one out of a 1000. And now we just made it one out of 200. So the risk went up. It’s kind of like finding a breast lump. The risk goes up. But most breast lumps are benign so most babies with bright white spots in the heart are fine, too. But do you see how it changed the risk? Now what do you do? That phone call, how did it make you feel? Right, you’re worried. Yes. So we’ve got to do something else.
Now what we actually do most of the time is when we see a bright white spot we look at a lot of other things that are associated with problems. If all we saw was a bright white spot and the baby otherwise looked normal, the chances are probably closer to that one in a 1000. So the question is, do you really even want to know if all we saw was a bright spot? If everything else looked totally normal, do you want the phone call? Would you want to know? Some people choose not to know. And in some of the institutions in our system and in the country, sometimes we’ll give you a choice. Do you want to know if we see one minor marker? Now in our situation, if we see two minor markers or anything major we’re always going to tell you. But if you say, “Look I don’t want to know about one minor marker,” then we won’t tell you. Now a lot of us, if we only see one minor marker, we don’t do anything extra anyway because if the baby otherwise looks normal the risk is pretty low. Okay?
So hopefully if any of you happen to be on the backside, the unlucky side of that phone call, you’ll understand that we’re serious — the baby probably is normal, it just means we do other testing. Okay? Does that make sense? Yes.
Okay so let’s just summarize for a minute what we’re going to do if we do the screening ultrasound, and for everybody we will do a screening ultrasound if you choose to do so, around 18–20 weeks. While we’re doing that ultrasound we will look at some keys things, like how many babies are in there? Is the baby doing well heartbeat-wise? Where is the baby? Is the baby in the uterus where it’s supposed to be? Right? Things like the placenta location and the amniotic fluid, are they normal? And then we’ll look at your dates and size and make sure that they’re just what we expect. Okay, so if we can confirm all those things, those are the most important ones from our perspective.