Maternity - Pregnancy, part 3: GTPAL, Naegele's Rule, and Prenatal Labs/Diagnostics

Hi, I'm Meris, and in this video, I'm going to be talking to you about the gravida and para numbers, Naegele's Rule for calculating estimated due date, and I'm also going to be talking to you about the different types of labs and diagnostics that are done during prenatal care. So I'm going to be following along using our maternity nursing flashcards. These are available on our website leveluprn.com. And if you already have a set of your own, I would absolutely invite you to follow along with me. So let's go ahead and get started.

We're going to be starting talking about GTPAL. These are the numbers used to represent how many pregnancies and different types of deliveries or outcomes that a patient has had.

So G stands for gravidy. Gravidy with a D, not a T. So gravid means pregnant. So gravidy means how many times has this patient been pregnant, no matter what the outcome? Okay? No matter what the outcome, how many times has this patient been pregnant? Then, we're moving on. So, G, gravidy, just talking about pregnancy. Now we're moving on to the para numbers. So this is how many times a patient has had different types of outcomes.

So term GT. T is for term. So the next number means how many term deliveries, meaning past 38 weeks, has this patient had.

Then, we move on to preterm. How many preterm births has this patient had? That's going to be from the age of viability, around 20-ish weeks, 24 weeks through 37 weeks. Okay. So how many times has this patient been pregnant? How many term deliveries? How many preterm deliveries?

The next one, the A in GTPAL, is abortions.

Now, keep in mind that abortion is a medical term, which means that a pregnancy has ended. It is not a term that means elective or therapeutic abortion, meaning something that was induced. It can mean that, but it can also refer to spontaneous miscarriages. I want to caution you to be very careful about how you use this word around patients, especially those who have had miscarriages or losses. We in the medical community may know that this just means the loss of a pregnancy, but your patient may not.

And then, the L means how many children are living now? Okay? So I'm going to do a quiz with you at the end. So see if you can calculate some GTPAL numbers.

And then gravida terms. Nulligravida means never been pregnant.

Primigravida means first pregnancy.

And then, multigravida means multiple pregnancies, two or more. So you will hear-- sometimes you'll see like, "Oh she's a primi," meaning she's never had a baby before. So just get to know those terms.

And then, moving on, we are talking about Naegele's Rule.

So Naegele was this guy who came up with the rule for how you calculate the estimated delivery date of a patient.

Now, the estimated gestational age in human beings is 40 weeks.

So Naegele said if you know the first date of the patient's last menstrual cycle,

subtract three months,

then add one week,

and then add one year.

It's very confusing. The point being, really what we're doing is we're getting nine months and one week in the future.

So we have Cathy's easier rule, which is add nine months and one week to whatever the patient's last menstrual period was. The first day of the last menstrual period is used to calculate this because it's 40 weeks from that date. So at conception, you're actually two weeks into the gestational cycle, if that makes sense.

All right. So, for example, if the first day of the last menses is April 1st of 2020,

Naegele says that you would subtract three months, which would make it January 1st, 2020, add one week, January 8th, 2020, and then add one year, January 8th, 2021.

Cathy's rule says April 1st, 2020. We're going to add nine months. That gives us January 1st, 2021. And then add another week, January 8th. All right.

Now, moving on, these last two cards are pretty hefty. Okay? There's a lot of information on them because it's super important in this class to understand what the testing is in pregnancy. It's very different from testing that you've learned about at any other time in the program.

So starting off, let's talk about HCG. This is human chorionic gonadotropin. It's the pregnancy hormone. This may or may not be done, and it just kind of depends on your patient. But it can be done.

Now, Rh factor. We talked about this in the last video. We have to know what the patient's blood type is.

We have to because if I am Rh-negative, and I have a baby who is Rh-positive, the first time, nothing is going to happen, probably. We're going to mix blood at delivery. And then, if I should ever become pregnant again in the future with an Rh-positive baby, my immune system is going to recognize that antigen as being foreign, as being a threat, and it is going to attack that baby in something called erythroblastosis fetalis. Okay? It's not a good thing. So we can end up with the baby dying because of this.

So if we take RhoGAM, which is an IM injection-- if we take RhoGAM, it's actually going to suppress that immune response so that we don't end up making those antibodies against the Rh factor. So you'll see here that we administered at 28 weeks - very, very important timing - but we also give it within 72 hours of delivery.

And then, any time there's some sort of pelvic or abdominal trauma or vaginal bleeding. Okay. Super important to know. So those were some labs.

MSAFP is another lab. MSAFP stands for maternal serum alpha-fetoprotein. So this means it's measured through the maternal serum, through the patient's blood, not through the fetus. And this helps to screen for some genetic abnormalities.

So an increased MSAFP is indicative of neural tube defects,

but a decrease in MSAFP can be indicative of a Down syndrome. And we do have our cool chicken here that MSAFP will be down in Down syndrome.

Now, it's important to note this is not diagnostic. It does not mean this is what's happening. MSAFP numbers can be off for a lot of reasons. So if we did get a high or a low result, then we would want to follow it up with an amniocentesis to confirm.

So then, the next thing on this card is the oral gestational-- I'm sorry, glucose tolerance test. So this is the gestational diabetes screening test. What this is, is going to be testing the patient's response to glucose to help us identify gestational diabetes.

So the one-hour glucose tolerance is the screening one that is done on all pregnant patients that consent to it, usually 24 to 48 weeks. No fasting is required. They're going to drink a 50-gram glucose solution. We're going to wait an hour, and we're going to draw their blood. If it is above 140, that's the magic number, 140, then we are going to move on to a three-hour glucose testing. If it's below 140, we say, "Good, you don't have gestational diabetes. You can carry on with your life." But if it's above that, then we're going to move on to the three-hour.

Now, with the three-hour, that's a fasting test. You have to arrive having had nothing to eat or drink except for water. And then they will give you 100 grams of glucose to drink. But before they do, they're going to draw your blood. So they're going to get a fasting level on you. Then, you're going to drink the stuff. Wait an hour. Then you're going to have a one-hour, a two-hour, and a three-hour blood test to see what your glucose was. 

Any two results being out of whack is diagnostic for gestational diabetes. So if I come in and my fasting level is a little high, but the one-, two-, and three-hour are good, it's fine. I don't have gestational diabetes. But if two, three, or four of them are elevated, then we are thinking, "Yep, this is gestational diabetes." So important to know those cutoffs so that you can help to better educate your patients.

All right. So that is it for the GTPAL, and also for the Naegele's Rule, and also some labs and diagnostics. I hope that was helpful. If it was, please like this video or leave me a comment so that I know. And you definitely want to subscribe so that you can be the first to know in the next video in the series drops. Thanks so much, and happy studying.

First, let me say, so I passed my one-hour glucose with my daughter, and my first baby, and that was great. And then, with my second one, I failed miserably, and I had to do the three-hour. And I passed, but I am a very hard stick. So it was a very treacherous and scary three hours. But, okay.

So let's do a GTPAL calculation.

So you have a patient who has had 2 live births.

She has had 2 term deliveries.

She has had 1 preterm delivery.

And she has had 7 miscarriages.

She currently has 2 living children.

So what is your GTPAL calculation for this patient? Go ahead. Pause it if you need to think about it. I'll be here when you're done.

So the G should be 10. Right?

So she had 2 live births-- 2 term deliveries-- I'm sorry.

A preterm delivery.

And then she had 7 miscarriages.

Right? So we have 10 total pregnancies.

And then, the T number should be 2. She had 2 term births.

The preterm, the P, should be 1.

She had 1 preterm birth.

And then the A, number of abortions, should be 7. She had 7 miscarriages.

And then the L number should be 2 because she only has 2 living children.

I hope that was helpful.