Maternity - L&D, part 6: Fetal Heart Rate Patterns - Normal and Abnormal Findings, VEAL CHOP

Hi, I'm Meris with Level Up RN. And in this video, I'm going to be talking to you about fetal heart rate patterns. We're going to talk about normal fetal heart rate patterns, what we expect to see, what kind of things are okay, and then we're also going to talk about some abnormal findings and the causes of those things and what we should do about them. So I'm going to be following along with our Maternity Nursing Flashcards in the Labor and Delivery section. If you have a set, I would invite you to follow along with me. And if you don't have one, you can get a set for yourself on our website, leveluprn.com. Okay. Let's get started.

So first off, let's talk about normal findings for fetal heart rate. These are things that we expect to see or things that are okay to see. So first and foremost, let's just talk about the heart rate itself.

The normal fetal heart rate baseline is going to be between 110 and 160 beats per minute. So we want to first check and see what the rate is of the fetal heart rate so that we can see, is this in the right range? Is it too slow, too fast, that sort of thing.

Now when we talk about accelerations, if you have seen the video about the nonstress test, I talk about what accelerations are in that video. But accelerations are what they sound like. It's where the fetal heart rate accelerates from its baseline level, and that's going to be by at least 15 beats a minute. So it's going to increase by 15 beats per minute, and that's going to be sustained for at least 15 seconds. So that's what an acceleration is. And this is a good thing.

This is actually really reassuring that the baby is getting enough oxygen and things are okay because accelerations happen in response to fetal movement and just kind of the impact of the world around them. Things like vaginal exams also can cause acceleration. So these are good. These are normal. These are reassuring. We like them.

Now, decelerations, decelerations are also what they sound like, but we have a couple of different types. So in this case, when we're talking about things that are okay or normal, we're talking about early decelerations. And what this means is that it's in relation to a contraction. So when we talk about early or late, we're talking about where does it happen in relation to the patient's contraction?

So an early deceleration is going to be a mirror image like a flipped image of the contraction. So the contraction is going to come up like this. It's going to peak and come back down. The deceleration is going to come down like this. It's going to bottom out and then come back up. But the peak of the contraction and the very bottom of the deceleration are going to match up. They are happening in sync, so they should look just like flipped versions of one another.

Now, an early deceleration, this is going to be benign. This is not something where we need to intervene. This is typically because of head compression. So that early deceleration in fetal heart rate is going to be caused by head compression, compression of the fetal head. And like I said, that mirroring is going to be the most important thing to understand when you're looking for, is it early or is it late?

Now, variability, variability has to do with, how does the heart rate change second to second?

So we should see fluctuations of the fetal heart rate by 6 to 25 beats per minute around the baseline. So that's why if you ever look at a fetal heart rate tracing, most of the time you're not just seeing a straight line across that's showing you it's 120 beats a minute, and it's just really staying there. That is not normal.

So the variability indicates that we have a healthy nervous system. A healthy nervous system of the baby is going to be demonstrated with this moderate variability. Remember that variability is a term that can be used-- you have to qualify it. You have to say how much there is. So you can have absolute variability. You can have minimal variability. You can have marked variability. But what we want is to see moderate.

Moderate variability is the reassuring type of variability.

So now let's move on to abnormal findings. So from this point out, we're talking about things that are not normal, not expected, and probably not okay.

So first up, we're talking about fetal bradycardia. Now, remember that 110 to 160 is the normal baseline.

So fetal bradycardia is going to be anything that is less than that 110. However, it has to be sustained for greater than or equal to 10 minutes. So we're not going to call it fetal bradycardia if we have a drop in the heart rate and then 30 seconds later it comes back up, right? That would probably be more a deceleration.

But why does this happen? Well, there's a lot of reasons that fetal bradycardia can happen. If we have prolonged cord compression, we're not getting enough blood to the baby. That's going to increase the blood pressure. It's going to decrease the heart rate. Umbilical cord prolapse, same kind of situation there. Anesthetic medications, so medications given to mom can affect baby. So that has to be a consideration as well. And fetal heart abnormalities, of course, could cause that as well. But if I am not-- if my heart is not beating appropriately, I am not oxygenating my body appropriately, right? I'm not getting that good oxygen-rich blood where it belongs. So when you think fetal bradycardia, you've got to think, "This baby isn't getting enough oxygen." That's a big problem.

So things that we can do for it, side-lying position is always a good choice, repositioning the uterus so that it may not be on the umbilical cord, for instance, can be helpful, oxygen, IV fluids, but most importantly, we need to notify the provider, right? That's going to be really important, but we want to stay at the bedside with mom too.

Now, on the flip side, fetal tachycardia.

So that's going to be anything above 160 beats a minute, sustained for 10 minutes or longer, right? So same parameters, just on the opposite side of the spectrum.

Now what can cause this? A big one is maternal fever. So if mom has a fever or an infection, then that's going to affect mom's metabolic rate, which in turn is going to affect baby, also, fetal hypoxia, right? If I'm not getting enough oxygen, my heart rate is going to start to go up to try and compensate for that. Maternal hypothyroidism, again, anything that's affecting mom's metabolic rate will also affect babies. And then cocaine use, cocaine use, it's a stimulant for mom. Therefore, it's a stimulant for baby.

So what are we going to do about that? Well, we need to treat the underlying cause if that is the case, so giving an antipyretic for mom's fever, for instance. IV fluids and oxygen, of course, are going to be helpful if they are indicated for that purpose. But there's a line here that I would like to draw your attention to if you have this card as well.

Fetal tachycardia accompanied by decreased variability is indicative of severe fetal distress, so heart rate goes up, but variability goes down. That's a really bad, scary thing. We need to be thinking about immediate interventions to get this baby earthside.

Okay. Up next, we're going to talk about late and variable decelerations. We already talked about early decels, right? Those are those exact mirror images of the contractions. Those are okay. They're caused by head compression. That's all right. But when we talk about late and variable, these are not normal findings.

So a late deceleration is not going to be that perfect mirror image of the contraction. Instead, it's going to be offset slightly. So what you're going to see is that the contraction comes up and goes down, but the base of that deceleration of the heart rate is going to come after the peak of the contraction.

So it's later than the peak of the contraction. That's a late deceleration. So that can also have a prolonged return to baseline, meaning that it takes longer for it to kind of come back up to where it should be. So those are the scary ones that we don't like to see.

And the biggest cause here is going to be uteroplacental insufficiency. You can sometimes hear this just called placental insufficiency. But essentially, we have decreased blood flow coming to the baby, which in turn is going to lead to fetal hypoxia. And that's where we see that drop in fetal heart rate.

So we have a cool chicken here right here on this card. We have a cool chicken that I want to point out because I love this one. I think it's very helpful. It's how to treat any sort of deceleration, but specifically, the late one here we're talking about is LION. And I would actually say it's LIONS, but I'll get there in a second. So LION is for left-lying positions. We're going to turn mom onto the left side. I is for IV fluids. We're going to administer IV fluids per order. O is for oxygen, and you can also remember the O means to discontinue oxytocin. O for oxytocin, discontinue it. And then N for notify provider. So those are the letters in LION to remember treatments for late decels. I would say that the S is to prep for surgery. So if we have late decels and we're not able to resolve them, doing these other LIONS interventions, then preparing for surgery, delivery via C-section is going to be the next thing to do.

Moving on to variable decelerations. Variable decelerations, I remember V for variable and they kind of look like a V. They have a very sharp, dramatic drop and usually a pretty quick recovery. So the fetal heart rate tracing, when you see a variable decel, it's going along. It drops. It comes back up, and it keeps going along.

Now, the cause of variable decels, that's going to be umbilical cord compression. So cord compression is going to lead to increased fetal blood pressure, which then is going to lead to decreased fetal heart rate. So with this one, we need to get the baby off of the cord. So how can we do that?

Well, we can put mom in the Trendelenburg position. Trendelenburg is where the head is down, and the feet are up. So if you have a patient laying flat, then you're going to tip them like this, and hospital beds have the ability to do that. You're going to put the head down, feet up. That's going to use gravity to shift the uterus, shift the baby, potentially shifting the baby off of the cord.

Another one would be knee-chest position, again, to try and move the contents of the uterus around to get baby off of the cord. Now, again, we're going to administer oxygen, discontinue oxytocin, notify the provider. That's all important stuff all of the time, right?

But amnioinfusion may be indicated. And this is for patients who have oligohydramnios, meaning they have too little amniotic fluid. Well, that amniotic fluid works as a buffer and a cushion, so it would be between baby and the cord and providing all of this nice, cushioned environment. If I don't have enough, then if that cord is underneath baby, there is no cushion there. So we can do an amnioinfusion, which again, is what it sounds like. We are infusing synthetic amniotic fluid into the uterus to provide that sort of cushioning environment as well.

Now, this card is my favorite one to sum up everything we just talked about. This is the VEAL chop card. So we have it spelled out here, right for you, in big letters. And it's a very clear card so that you can see exactly what we're talking about.

So VEAL chop, and I want you to write it out vertically, not horizontally, vertically, VEAL and chop so that the letters line up.

So V is for variable, and the C is going to be for cord compression. They line up.

Then we have the E is for early, so early deceleration lines up with the H, which is for head compression.

The A is accelerations, which lines up with the O, which means, okay. This is okay. This is a good thing. We're not worried about it.

And then L is for late as in late decelerations, which lines up with the P for placental insufficiency. So when you use this mnemonic right here, when you use this, you can line up and see the cause of each different kind of fetal heart rate variation.

So I hope that review was helpful for you. But now I'm going to give you some quiz questions so that you can test your knowledge and see if you picked up on some of the really key points of this video.
Okay. So first up, I want you to tell me what is the normal baseline for fetal heart rate? Think about that, normal baseline for fetal heart rate.
For which fetal heart rate pattern would you want to place the mom in Trendelenburg or knee-chest position?
What does moderate variability in the fetal heart rate indicate? What does moderate variability indicate about the fetus?
Lastly, I want you to think about and tell me what is the cause of late decelerations? So what is the underlying cause of a late deceleration?