Transcript episode #37:All About Amniotic Fluid: What It Is and How It Helps Your Baby
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00:00 In today's episode, you're going to learn all about amniotic fluid.
00:05 Welcome to the All About Pregnancy & Birth podcast. I'm your host, Dr. Nicole Calloway Rankins, a board certified Ob Gyn physician, a certified integrative health coach and creator of The Birth Preparation Course, an online childbirth education class that will leave you feeling knowledgeable, prepared, confident, and empowered going into your birth. Quick note, this podcast is for educational purposes only and it's not a substitute for medical advice. See the full disclaimer at www.ncrcoaching.com/disclaimer.
00:42 Hello, hello. Welcome to another episode of the podcast. This is episode number 37 and I am so glad you're here today. So on today's episode you are going to learn about amniotic fluid. Amniotic fluid is really important for your baby and your baby's health. So I'm going to help you understand what it is, why it's important, where it comes from, what happens if it's too low, and also if it's too high. Now, before we get into the episode, a couple of quick things.
01:16 First, let me give a listener shout out. This is from Mini Jassy. She left me this review on apple podcast and it says, "Awesome podcast". This is the title of the review. "Dr. Nicole Rankins brings you the knowledge and resources you'll need to make an informed decision about the birth you want and the resources you'll need to heal after birth, including breastfeeding knowledge on maternity leave, process, midwives, ob Gyn, rare infant conditions in home care, et cetera. She has an open mind and process to move the OB Gyn world forward. I'm hoping this podcast continues the conversation for mothers to heal better during the fourth trimester postpartum. Also, her voice is so relaxing as well. Keep up the great work." Mini Jassy. Thank you so much for this review and I also appreciate the suggestion for talking about postpartum health. It's definitely something that I want and need to cover on the show, so that'll be something that I put on my list to get to for sure in the future and add some great episodes. I also appreciate the warm comments about my voice. I've had a few people tell me that, which I've been surprised about, so I appreciate that my voice is so relaxing, so thank you so much for that review.
02:37 Now the second thing is that I would love to have you join me in my free live online class, How to Make a Birth Plan That Works. It takes all the confusion out of making a birth plan and gives you a super clear process on how to make a birth plan that works to help you have the birth that you want. Women love this class and I only do three or four times a month or so, so go to www.ncrcoaching.com/register to sign up for the next class. And if you want to go even deeper with me helping you get ready for your birth, then check out my online childbirth education class, The Birth Preparation Course. This fantastic class gives you all the information you need to be knowledgeable, prepared, confident, and empowered to have the birth you want. It's incredibly comprehensive. You'll learn about how to get in the right mindset for your birth, that's really important. Everything you need to know about labor and pushing a baby out the truth about things like pitocin and c-sections as well as things you need to know to get you off to a good start as a new mom. So you can check out what's in the class at www.ncrcoaching.com/enroll. The free birth plan class is a great way to get a flavor for The Birth Preparation Course. So again, the free online class is www.ncrcoaching.com/register or if you're ready to jump into The Birth Preparation Course is www.ncrcoaching.com/enroll.
04:05 Okay, well let's get into today's episode of our amniotic fluids. So again, what I'm going to cover is what is it, what's in it, where does it come from, how do we measure it? And then also what it means when amniotic fluid is too low and also what it means if you have too much amniotic fluid around your baby. So first things first, what exactly is amniotic fluid? Well, amniotic fluid is just the liquid that surrounds your baby and it appears after the first few weeks of pregnancy or so, and it has a number of important functions that are really and truly essential for your baby to grow and develop normally.
04:45 So one thing that it does is it cushions the umbilical cord from being compressed. The umbilical cord is of course your lifeline between the placenta and your baby. It's how your baby gets all of their nutrients, how your baby gets rid of wastes. So the umbilical cord is important and if it's compressed then nothing's going through the court, so the amniotic fluid keeps the umbilical cord from getting squeezed or compressed between the wall of the uterus and your baby. So it kind of float in the fluid. The amniotic fluid also has antibacterial properties that help provide some protection from infection. It also serves as a reservoir of nutrients for your baby. It provides the necessary space and also contains some things called growth factors that help your baby's lungs develop appropriately, and your baby's musculoskeletal system develop appropriately. That's the muscles and the skeleton and also the gastrointestinal system to develop appropriately.
05:52 Babies actually breathe and swallow amniotic fluid to help some of those systems develop. And then finally it helps to protect your baby from any trauma. If for instance, you fall and hit your belly, the amniotic fluid acts as kind of a cushion to help protect your baby from getting hurt. So as far as what's in amniotic fluid, like 98% of it is water. It's mostly water. And then the remaining 1-2% is solids. So like proteins, carbohydrates, electrolytes, fats, there are hormones in there, there are also cells. Your baby cells kind of shed in there. So skin cells, respiratory cells, intestinal cells, urinary tract cells, stem cells. There can also be hair, blood cells, and sometimes a little bit of poop. That's called meconium. And that's not typically until the end of pregnancy that we see that.
06:47 So where does amniotic fluid come from? Well early in pregnancy we believe that it's derived mostly from the placenta and it also comes from secretions from the surface of your baby when your baby's a teeny tiny embryo that there's some secretions from the surface of the body that help contribute to amniotic fluid. But shortly into the pregnancy, late first trimester, early second trimester, most of the amniotic fluid comes from your baby making urine. And babies actually make quite a bit of urine every day and babies towards the end of pregnancy, they make anywhere from 800 to 1,200 milliliters of urine a day. For comparison like a two liter bottle of soda is, you know, 2000 milliliters. So roughly like half of that is what your baby will make in urine during the course of a day. Now the question is will if your baby's making that much urine like, well, where is all of that going to? How does the fluid levels stay pretty constant?
07:58 Well, in addition to making the urine, your baby also swallows the amniotic fluid. Roughly your baby swallows anywhere between 500 and a thousand milliliters a day. So makes more urine, swallows less and what's left is the amniotic fluid around the baby. So the amniotic fluid volume doesn't really change very much from day to day. It stays fairly constant. But the amniotic fluid itself we believe is completely replaced every 24 hours. It's just this constant system of baby making urine, baby swallowing the fluid, baby making urine, baby swallowing the fluids. So it just turns over and over again every day but stays at roughly a constant volume.
08:49 So as I said, amniotic fluid is an important indicator of things that can happen in pregnancy and it can be a sign of distress. And the way that we measure amniotic fluid is ultrasound. It's really the only practical method that we have. So understanding amniotic fluid is a fairly new phenomenon in the sense that, you know, when my mom was pregnant with me, they weren't measuring amniotic fluid. I'm 44 years old. So it's a newer thing with ultrasound that we've measured amniotic fluid and we do it two ways. One is qualitative where we look at the fluid on ultrasound and we just kind of look at the picture subjectively and say, hmm that looks low, that looks about normal, that looks like a lot of fluid and surprisingly that's actually pretty accurate for people who have had a lot of experience looking at ultrasounds. Then we can accurately say that looks lower, that looks high, and then we follow it up with a more quantitative measurement. Now you'll always have what's called a quantitative or more exactl number measurement when, and it's kind of semi quantitative I should say because we can't measure it exactly cause we're taking something that's three dimensional and measuring it two dimensional.
10:05 But whenever you have a formal ultrasound then we always measure the amniotic fluid in a more formal or quantitative way. And there are two ways that we do that. One is called the single deepest pocket. It's also called the maximum vertical pocket or the largest vertical pocket. And what that is, is the vertical dimension, so like up and down in centimeters of the largest pocket of amniotic fluid that we can see on ultrasound that doesn't have any umbilical cord in it and it doesn't have any arms or legs in it. And we do that with black and white ultrasound, no color or anything. And when we measure that, you know, top to bottom, if it's less than two centimeters, that's considered low fluid or alagohydramnios and I'll talk about what that is in a minute. If it's between two and eight, then that's normal. And then if that maximum pocket is greater than eight, then that's polyhydramnios. And I'll talk about what polyhydramnios means later.
11:14 So we take what is a 3D phenomenon and measure it in a 2D way, two dimensional way, and then that depth tells us whether the fluid is low, normal, or high for the biggest pocket that we can find. Now the other way that we measure amniotic fluid is something called the amniotic fluid index, and that is calculated by basically dividing the uterus into four quadrants. So we go up and down through the belly button and then across through the belly button, and then that creates the four quadrants. I'm like literally sitting here drawing on my own belly to make four quadrants. But you go up and down through the belly button and across the belly button and it makes those four quadrants, the upper and lower quadrants. So what we do is we measure the pocket in each of those four quadrants.
12:10 The maximum pocket that we can find, again that doesn't contain any cord, doesn't contain any arms and legs. And this is just black and white ultrasound, no color flow or anything like that. We measure each of those pockets in centimeters and then add up the number from each of the four quadrants. So in that case alagohydramnios or low fluid is when the amniotic fluid index is less than five. It's normal if it's greater than five and less than 24 and then polyhydramnios is when the AFI or amniotic fluid index is greater than 24 centimeters. So the two ways are single deepest pocket and amniotic fluid index. Single deepest pocket is going to be a bit faster cause it's just that one area that you're measuring. Amniotic fluid index just takes a little bit more time and you also have to be careful that you're not accidentally going across quadrants, so to speak.
13:11 You may find slight variations in these definitions where the cutoff numbers, maybe it seems a bit different, but that's a general sense for how we measure amniotic fluid with either single deepest pocket or amniotic fluid index. We also use the same method for multiples. So when you have twins. Now, what it does it mean if the fluid is too low? That is something called alagohydramnios, and that is when the fluid is less than expected considering how far along you are in pregnancy. So for the single deepest pocket method, if we find the biggest pocket, if the depth is less than two centimeters, then that's alagohydramnios. Sometimes we shorten it and just say alago, or if the total AFI amniotic fluid index is less than five, then that's alagohydramnios.
14:05 Now having a normal amount of amniotic fluid, as I said, is really critical to have a baby move appropriately and grow appropriately and to cushion that umbilical cord from getting compressed. And when the fluid is low, these processes can be interfered with. And it can lead to malformations where the spine doesn't form appropriately, where the lungs don't form appropriately, the cord being compressed and then the absolute worst case death. Now as far as what causes low fluid, it really depends on the trimester. In the first trimester, we're not sure what causes low fluid. That is not something that's very common. Babies don't have a ton of fluid anyway in the first trimester. So if there really is not much fluid there, we're not sure what causes it. And I'll talk about what that means for the pregnancy in a minute.
15:02 Now in the second trimester, that's when baby begins to make urine. So if the fluid is low at that point, then we get concerned if there's a problem with the babies kidneys and the systems that make urines. So not just the kidneys. So is there issue with the kidneys? Is there an issue with the ureters, which are the tubes that run between the kidneys and the bladder? Is there an issue with the bladder? Is there an issue with the urethra, which is the tube that runs from the bladder to get urine outside of the body? So we have to look at all of those things in between and see if there's some sort of issue and that's why the fluid is low because either urine isn't being made, there's something wrong with the kidneys or it's being blocked and prevented from coming out of the baby's body. This is actually the case and about 50% of the time if we see low fluid and its first diagnosed in the second trimester.
16:02 The other most common reason for low fluid in the second trimester is preterm premature rupture of membranes or the water breaking early and that accounts for about 35% of low fluid in the second trimester. I should say like this isn't a very common thing that happens, so I don't want you to be paranoid or super duper worried. alagohydramnios is not a super common thing, but I just want you to be aware of it. Now, diagnosing low fluid or alago in the third trimester, the most common reasons are again, water has broken early, so premature rupture of membranes and that just means that it is broken before the onset of labor. So water is broken early. The other thing that may cause us to diagnose low fluid in the third trimester, and this is the first time that it's diagnosed on the call uteroplacental insufficiency where the placenta is just not working as well as we'd like because of conditions such as high blood pressure or preeclampsia or other things that can affect blood vessels, like if mom has diabetes. Very often if we see low fluid diagnosed in the third trimester for the first time, it very frequently goes along with growth restriction because the baby's not getting as much nutrients and blood flow in order to grow properly.
17:31 So if we first see alagohydramnios in the third trimester, very often it's accompanied with growth restriction where baby is not growing as well. The other thing that may cause fluid to be low is dehydration. And I'll talk about this as part of one of the things that may be a treatment. So just plain old dehydration. Mom is not taking in enough fluid, which means baby's not getting enough fluid because babies get everything from their moms. This can happen in the summer months where moms can get dehydrated and it can cause the fluid to be temporarily low. So how do I suspect or worry there's low fluid or alagohydramnios? Well, one thing we may notice is if when we do your tummy checks and measuring your tummy, if your uterus is measuring a lot smaller than expected, that is going to bring up some alarm bells. Is there something going on with the fluid or is there something going on with the baby not growing well, so that's going to trigger an ultrasound.
18:30 Of course, if a woman says she's leaking fluid, then that is going to cause us to look and make sure fluid isn't leaking or anything like that and look around with ultrasound and make sure that the fluid level looks normal. Sometimes it's just found, I should say often it's found on ultrasound done for other reasons for someone who is at risk but is getting regular ultrasounds during their pregnancy. So if a mom has diabetes or if she has hypertension or is she has lupus or you know some kind of other conditions during pregnancy that put her at a higher risk. We tend to do more frequent ultrasounds to monitor growth and some times that's when we'll pick up the low fluid and get that cause for concern. So most of the time we find it in the third trimester and we can't necessarily pinpoint a definitive cause for it, but those are the kinds of the things that we look for or that may cause us to have some suspicion or how we find alagohydramnios.
19:30 So to treat it there really is no treatment that's been proven effective in the longterm. There are a couple of things that may help in the short term. Hydrating you, so IV fluids and giving you tons of fluids to help kind of bring your hydration level up and then that passes along to the baby and increases the baby's urine and amniotic fluid. That takes some time. We usually don't see a change in the fluid for 24 hours after hydration, so that takes a little bit of time. So that's certainly something that we often try when the fluid is noted to be low and there's no obvious other causes. The other thing is something called amnio infusion. This is something that we only do during the course of labor where if we notice that the water's broken and there's some changes in a baby's heart rate, that suggests that the cord is being compressed, then we actually put fluid back in, so amnioinfusion infusion, fluid back in to help kind of provide that cushion back.
20:29 But that's only something that's done during the course of labor. So those are really the only two things that we have for amniotic fluid, low amniotic fluid. Really what we do is kind of watch it and monitor during your pregnancy. And what they do really depends on what the underlying condition is. So I can't cover that in great detail. So for example, if it's because your water's broken, then that's going to be managed one way. If it's because the baby has an issue with their kidneys then that's going to be managed a different way. So I can't go through all of those details. It really kind of depends on what the underlying reason is. But it almost always involves some sort of closer monitoring. In the case of your water being broken, then it may involve staying in the hospital. It almost always involves early delivery. It may be as early as 37 weeks, it may be even sooner if we notice that there are some other factors that are concerning as well.
21:32 So what does it mean for your pregnancy if the fluid is low? Well, if we see low fluid in the first trimester, that is actually a very bad sign and 95% of pregnancies that have low fluid noted in the first trimester will end in miscarriage. Now if we find low fluid in the second trimester, if it's kind of like on the border of being low, you know, just barely low, then most of those pregnancies go on to be normal. And this is between 13 and 24 weeks. That's the second trimester. But if the fluid is very low, like obviously low during that time, then unfortunately only about 20% of these babies will survive. And if they do survive then they have anatomic problems. They have functional problems. Things like skeletal malformations, contractures of the muscles, the lungs are not developed appropriately. So those things occur as a result of being in an environment where the fluid is low for a long time.
22:49 Now in the third trimester, what it means for your pregnancy, it kind of depends. The earlier in the third trimester that low fluid is diagnosed, then the more worried we are about problems happening. If it's diagnosed towards the end, then it tends not to cause any major problems. We tend to move towards delivery to prevent any problems that occur. So it kind of depends. In the third trimester, the earlier it's diagnosed, the more we're worried, but diagnosed for the first time in the third trimester, it's not as bad if it's diagnosed in the second trimester or first trimester.
23:28 So let's talk about the flip side or polyhydramnios, when you have too much fluid. I actually had this with both my pregnancies, so polyhydramnios it can also be known as hydramnios and that just refers to an excessive amount of fluid. We make the diagnosis of course by ultrasound, we can see it on ultrasound, you can look, that's that qualitative approach where you look and you say, hey, it looks like there's a lot of fluid. And then you follow it up with a more definitive measurement. And that's where we do either that max single deepest pocket with the depth of greater than eight centimeters, or the total AFI amniotic fluid index with those four quadrants, and if it's greater than 24 centimeters. Polyhydramnios effects one two, 2% of pregnancies. And they're really just a couple things that we know are the underlying reason.
24:23 It's typically caused because your baby is not swallowing as much. So baby is making urine but can't swallow or is not swallowing as much. So the extra fluid just collects. That was the case for me with my first daughter, she had an intestinal malformation called duodenal atresia, so her intestines actually weren't connected so she couldn't swallow amniotic fluids so it just kind of accumulated. And then the other thing that causes it is if babies make more urine, so either they're making more urine or they're not swallowing as much. So the most common things that cause those things to happen are what's called malformations. Or like I said, and an example is the case, like what my daughter had where her intestines more connected so she couldn't swallow fluids. Sometimes some genetic disorders are associated with this, like trisomies the trisomies 18, 13 sometimes 21 down syndrome.
25:25 Moms with diabetes also tend to have or may have extra fluid. We don't exactly know why that's the case twins. Those babies may have extra fluids and then if babies have anemia, then there can be extra fluids. There's some rare causes, like some viral things that can occur, but for the most part it's going to be malformation. Mom has diabetes, or in many cases we don't know what causes it and it's just what's we call idiopathic. I should clarify actually most cases we don't know what causes extra fluid. About 40% that as best we can tell our what's called idiopathic, we don't know where it comes from, and then about 30% are associated with one of the anomaly, so something's going on with the baby and then 25% with diabetes.
26:18 Now, the way that we suspect it is that the uterus is bigger than we would expect for this stage in pregnancy, so that would trigger an ultrasound. So look at the fluid and look at the baby's growth. Maybe incidentally found again because we're looking for an ultrasound for a different reason. Now, most of the time it's not symptomatic, so having this extra fluid, you don't really notice it or it, but sometimes you may feel sympotamic. You may feel short of breath. I know that with my first pregnancy I certainly felt a little bit short of breath. You may notice like some contractions, nothing major but some contractions and then just some discomfort with that extra fluid being there. As far as what it means for your pregnancy, if it's idiopathic, meaning we can't find the underlying reason, most of the time it resolves, especially if it's only mildly elevated. For my second pregnancy, it was just mildly elevated, like it was never super duper high. Whereas the number got quite high from my first one. I don't remember the exact number, but it was pretty high.
27:28 Extra fluid can be associated with having some issues. It can cause you to go into labor early because the uterus is just so big. If your water breaks early, it can cause early delivery to happen. One of the big things is babies being not positioned with head down. As you can imagine, they got all that fluid to swim in, so it's easy for them to get into positions other than head down or they get into head down and they flip right out of that. So babies having what we call an unstable lie is common with extra fluid. Umbilical cord prolapse can be a concern because normally when the water breaks, if there's a normal amount of water and the head is nice and applied to the cervix, when the water breaks, then the head is sitting right there on the cervix and it keeps the cord from falling out into the vagina. That's what umbilical cord prolapses is, when the cord falls out into the vagina. But if the baby has all this fluid and the babies kind of just sort of floating around and the water breaks, and the cord comes out first, that's a true emergency. It's going to compress the cord. That requires a true, true emergency stat c section, so there's an increased risk of that with extra fluid. That's why we have to be careful about breaking your water.
28:50 The other things that can happen is that once your water breaks, it's going to shrink down the size of your uterus a lot and fairly quickly, and sometimes that causes the placenta to separate away from the wall of the uterus early. That's called a placenta abruption. So that can happen and then the final thing is that the uterus just may be a little bit lazy after delivery, so it's been kind of big and it takes a minute for it to kind of squeeze down and close off all those blood vessels afterwards so there can be increased bleeding related to having extra fluid. Overall for women that have extra fluid or polyhydramnios, there's a two to five fold increase risk of morbidity related to having that extra fluid, so it does have some increased risks associated to it.
29:45 Now, the management of what we do when a woman has extra fluids depends on how far along you are in pregnancy, how severe it is, if there's symptoms and then the cause. So in mild polyhydramnios where the fluid's only slightly elevated, usually we may just do a little bit of extra monitoring with non-stress tests once or twice a week until delivery. Occasionally, if it's really, really severe, then we may offer to do something called an amnio reduction. Where we remove some of the extra fluid is when moms are really, really uncomfortable and have shortness of breath. I actually had this done for my first pregnancy because right before I went into labor it was maybe thought that I was having so many contractions because I had so much fluid so maybe reducing the amount of fluid and that would help decrease the contractions. It did not, but I did have the amnio reduction procedure where basically they stick a needle in your belly, it's so easy to do because there's so much fluid you can see everything and just drain the fluid and they drained off about one liter of fluid to see if that would the help.
31:00 You don't want to take off too much because you don't want the shrink the size of the uterus too fast, but if it's really, really bothering you, that extra fluid taking off some of the extra fluids is an option. There are risks to the procedure and your doctor would have to describe that for you. Now during labor we get worried, like I said about babies moving around and not staying in that head down position. Also run the risk of the cord prolapse like I talked about or abruption like I talked about. And then we just have to be careful as well about using pitocin because we don't want things to go faster or sooner then they need to with that extra fluid. Most of the time women with extra fluids will get induced somewhere between 39 to 40 weeks. It may be a little bit earlier if there are symptoms involved.
31:54 Okay, so just to summarize, amniotic fluid is really important for your baby's growth and development to grow normally and for all of the systems in the body to grow, lung, gastrointestinal system, musculoskeletal system. And we know that both low and increased amounts of fluid can cause issues and problems for a pregnancy. Fortunately, neither extreme is common, but they do require monitoring and special care. It really just depends on the underlying cause and that way we can ensure that you and your baby are safe. All right, so that's it for this episode of the podcast. Be sure to subscribe to the podcast in Apple podcasts or wherever you listen to podcasts. And if you feel so inclined, I would love it if you leave an honest review in Apple podcast, that's formerly known as iTunes, they've changed it all to Apple podcasts. It helps other women find my show and then I can also give you a shout out on a future episode.
33:01 Also, be sure to check out my free class, How to Make a Birth Plan That Works. That's www.ncrcoaching.com/register. I do the class about three or four times a month. Women really love this class and you can check that out and sign up for the next class. There's limited space available to each class, so sign up so that you don't miss it. I do send out a video afterwards if for some reason you can't make the time, but it is definitely fun and enjoyable if you make it live to the class. The free class is a great way to get a flavor for my online childbirth education class, The Birth Preparation Course. But if you just want to learn directly about The Birth Preparation Course, go to www.ncrcoaching.com/enroll. And that is a fantastic option for childbirth education covers everything from mindset, which is so important, what you need to know about labor and pushing a baby out, help you be informed about possible things that could happen like safely using pitocin or cesarean birth information to help you get off to a great start as a mom. Again that's www.ncrcoaching.com/enroll to learn about the course or www.ncrcoaching.com/register to learn about the free class on making your birth plan. And of course I'll link those in the show notes.
34:19 Now next week on the podcast is a birth story episode. Rachel had a really empowering unmedicated hospital birth, so come on back next week to hear her story. And until then, I wish you a healthy and happy pregnancy and birth.
34:36 Today's episode is brought to you by Women's Wellness Coaching by Dr. Nicole Calloway Rankins. Head to www.ncrcoaching.com to check out my free one hour mini course on how to make your birth plan, as well as my comprehensive online childbirth education class, The Birth Preparation Course with over eight hours of content and a private course community. The Birth Preparation Course will leave you knowledgeable, prepared, confident, and empowered going into your birth. Head to www.ncrcoaching.com to learn more.