“Cervical length screening” – with Dr. Simi Gupta

Dr. Fox: Welcome to today’s episode of “Healthful Woman,” a podcast designed to explore topics in women’s health at all stages of life. I’m your host, Dr. Nathan Fox, an OBGYN and maternal-fetal medicine specialist practicing in New York City. At “Healthful Woman,” I speak with leaders in the field to help you learn more about women’s health, pregnancy, and wellness. Dr. Simi Gupta, welcome back to the podcast. How are you doing? And how are you feeling? I heard you’re a little bit under the weather.
Dr. Gupta: I am. Thank you for having me back. I have a little bit of a cold that my toddler gave me, but otherwise, doing good.
Dr. Fox: That’s good. They’re just, you know, piles of infestation. Those kids, it’s unbelievable.
Dr. Gupta: That’s exactly right. He started preschool. And I think this is what I’m in for now.
Dr. Fox: You now have every bug that every child in the preschool has.
Dr. Gupta: And that’s for the year.
Dr. Fox: Wonderful. Well, you sound okay, maybe a slight…a few notes lower than normal. But it’s all good. We get baritone Simi Gupta today.
Dr. Gupta: Sounds good.
Dr. Fox: And we’re gonna be talking today about cervical length screening. So, what is a cervical length? What are we talking about here, Simi?
Dr. Gupta: Right. So, as most people know, your cervix usually shortens, and then starts to dilate, or open when you go into labor. And for most people, this happens towards the end of the pregnancy at eight or nine months. But for some people, it starts to shorten or dilate earlier in the pregnancy, and those patients are at a higher risk for preterm labor. So, what we’ve discovered is that we can measure the length of the cervix on ultrasound, and if we find that it’s shortening earlier in the pregnancy, then we know that those patients are at a higher risk for preterm labor. And we can talk about different management strategies in that case.
Dr. Fox: Yeah, I think it’s really interesting that there’s an ultrasound test that we can do, that has a lot of prediction for what’s gonna happen in terms of labor, you know, weeks or months down the road. I think that that’s a really neat concept that, I don’t know, most people find kind of fascinating that that’s even an option. You know, because usually it’s the end of pregnancy and I’m, you know, doing an ultrasound of the baby, and I’m looking at the heartbeat and, you know, baby’s waving and tossing and they’re like, “Does the ultrasound tell you when I’m gonna deliver?” I’m like, “Well, this doesn’t.” You know, if the baby held up a sign saying, “I’m going into labor on Tuesday.” That’d be awesome. But we don’t get that. But we’re talking about way earlier in pregnancy, like, well before people are thinking about delivery and labor. This is like, you know, we started with the second trimester, you know, like 16 weeks. That’s pretty early. And that that could have really relevant predictive value for later in pregnancy is quite a concept.
Dr. Gupta: I agree. This is definitely one of the big things that’s kind of come out in predicting preterm birth at the last maybe like 10, 20 years or so.
Dr. Fox: Yeah. And then, as you said, there is potential to intervene if the cervix is short. It’s not just information, although there is an argument to be made that the information alone might be valuable. But there is the potential to intervene. And we’ll talk about that I think a little bit later in the podcast. But for now, we have this idea that you can screen the cervix with an ultrasound. So, the first question I wanna ask you is, when do we do it? So, when do we start it? How often might we do it? When do we finish? Like, how does that work timing-wise?
Dr. Gupta: Yeah. So, we usually start somewhere around 16 weeks or the beginning of the second trimester. The reason for that is kind of the lower uterine segment, or the lower part of the uterus has to start to develop so that we can measure the cervical length fairly clearly. And that starts to happen around the beginning of the second trimester. So, we usually start around 16 weeks. And then you could technically measure it at any point after that, and when people stop measuring it kind of depends on when they feel like the information is less useful to them.
So, many people will stop measuring after about 24 weeks, because some interventions haven’t been shown to be…aren’t done after 24 weeks. Other people will do it later as far as 32 weeks. And how often you do it kind of depends on the circumstances. It can be every two weeks, it can be every week. It can be just once in the middle of the pregnancy. So, it just kind of depends on why you’re doing it, and what you’re looking for.
Dr. Fox: Yeah, I think there’s a lot of really important points you brought up, the first about the sort of the earliest we would do it. If people ask, you know, at 8 weeks, and 10 weeks, and 12 weeks, “Can we measure the cervix?” And you can, but the problem as you said is, we don’t really…we can tell where the cervix, you know, begins I guess on the outer edge of the cervix. But it’s hard to tell what is the other end of the measurement that we’re gonna do because it sort of morphs into the lower part of the uterus. And you really need the uterus to sort of balloon out till you can differentiate like what’s cervix and what’s uterus.
And so, earlier than 16 weeks, again, we’ll get measurements if someone really needs it or wants it, but it’s not gonna be so predictive because it’s not as accurate, so to speak, of what’s actually the cervix that we’re measuring. So, I agree, usually 16 weeks, rarely, we’ll do a little bit earlier. But that’s about it. You know, the upper limits of when you measure it, that’s really an area of controversy.
I know we do measure it past 24 weeks and, sort of, you know, going around the country and talking to people or lecturing, you know, people get really mad about that sometimes, like, “Oh, my God, I can’t believe [SP] you do that.” I was like, “You know, you can technically…you know, there’s studies about measuring it at the end of pregnancy to sort of predict when someone’s gonna go into labor.”
You know, we don’t do that. But it’s not a particularly dangerous test or harmful test. It’s just, you know, potentially a little bit annoying, I would say. You know, it’s a vaginal ultrasound. That’s what we’re doing. And we’ll talk about that as well.
But, as you said, it’s really case by case, and it’s sort of different. Clinics do it differently. Different doctors recommend it differently. Within a certain place like ours, it’s based on you know, who the patient is and what her risk factors are. So, that’s when we do it. And we sort of just touched on how do we actually measure the cervix. Like, what are our options with ultrasound?
Dr. Gupta: Right. So, the most accurate way of measuring the length of the cervix is by doing a transvaginal ultrasound. But, you know, people have started to do other studies on doing abdominal ultrasound to look at the cervix, because for some patients, it’s uncomfortable to have a transvaginal ultrasound, and also takes some more time and different things. So, you can look at the surveys on abdominal ultrasound as well. It’s just not quite as accurate as a transvaginal ultrasound. So, sometimes we’ll start with an abdominal ultrasound. And if it looks like it might be a little bit short, then we will do a transvaginal ultrasound to get the most accurate measurement. Other times we’ll go straight to a transvaginal ultrasound. Kind of depends on the indication.
Dr. Fox: And what do you mean by that? Like, for what indications might we automatically look vaginally versus let’s look abdominally first, and only if it sort of looks suspicious do we look vaginally?
Dr. Gupta: Right, so if someone’s at a high risk for a preterm delivery, then we usually say we need to start with a vaginal ultrasound and get the most accurate measurement possible. For a patient who is low risk for a preterm delivery, then we will usually look on an abdominal ultrasound at just a routine 20-week or detailed anatomy scan, and only if it looks short, then will we do a transvaginal ultrasound.
Dr. Fox: Yeah, and this is another area of controversy around the country and around the world of exactly what is the best strategy, right? So, I mean, you can either say, I’m gonna do a vaginal ultrasound on every single person who’s pregnant at some point in pregnancy, and make sure to do it 100% of the time, because it’s the most accurate, reliable, predictive, whatever you wanna say, and that…some people do that. And that’s reasonable. The upside is, you’ll get a lot of information for everybody. The downside is everybody has to have a vaginal ultrasound, which, like you said, adds a lot of time, can add cost, it could be uncomfortable for people.
Another option is to say, we’re gonna do an abdominal ultrasound on everybody. And only if it’s abnormal, or possibly abnormal, will we then sort of reflect to the vaginal ultrasound. And then there’s something in between where you say, all right, which will we do? For some people, who we think are really high risk enough that we need to get the best measurement possible no matter what, we’ll do a vaginal automatically. And for others who are sort of, you know, lower risk, and more typical risk we’ll sort of start with the abdominal only if it looks concerning when we go to vaginal. I’m not saying our way is the best way. There’s, you know, people who do it all three ways. And they’re all reasonable, it’s just a little bit different based on, you know, people’s practice, patterns, and their training, and potentially the availability of vaginal ultrasound, and how many machines they have, and how many patients they have. They’re gonna…there’s also logistics that go into this. So, people are gonna sort of see different things around the country.
Dr. Gupta: Right, I completely agree. It kind of depends on the patients, and the ultrasound unit, and the resources available.
Dr. Fox: Yeah, I think that one of the things that we’ve learned over the years is that there does seem to be value to doing some assessment of the cervix in the second trimester versus not looking at all, right? And whether that assessment is abdominal, which usually people getting an ultrasound anyway is abdominally, so [SP] just means sort of like making sure to get that picture to look at the cervix, or whether it means automatically doing vaginal versus let’s do nothing. I think that there’s been a lot of good evidence showing that it makes sense to do some sort of assessment of the cervix on everybody.
Dr. Gupta: Right, and then that is partially true because, you know, again, some women have risk factors for preterm deliveries, the biggest risk factor being a prior preterm delivery. But if it’s your first pregnancy, you’re still at a small risk for a preterm delivery somewhere around 10% to 12%. And for those patients, it is useful to have some assessment of the cervix, so that women may not have to have a preterm delivery before we realize that they’re at a higher risk for having one.
Dr. Fox: Yeah, and I think one of the big reasons this changed because when I was training, there was no sort of standard recommendation to assess the cervix by ultrasound, again, one way or another. And I think the reason is, there’s this paradigm in screening that you’re really not supposed to do a screening test on everybody, on the whole population, unless there’s some intervention if you find a problem, right? Because otherwise, you’re just gonna be telling a whole bunch of people, you’ve got a problem, and there’s nothing we can do about it. And you may choose to do that on an individual level and say, “All right, you know, I believe for my patients, it’s worthwhile to know this, but to sort of recommend it universally, is really tough if there’s nothing you can do about it. And the next thing we’re gonna talk about, which is sort of what do you do if the cervix is short?”
I think that over the past 10, 20 years, the data supporting the various treatments that are available for someone with a short cervix has gotten better, and better, and better, such that there really is something we can offer people with a short cervix, that seems to be helpful. And so, it makes a lot more sense to check everybody, even those who are at the lowest risk, again, in some capacity, whether it’s abdominally, or vaginally.
Dr. Gupta: I completely agree.
Dr. Fox: So, let’s talk about those treatments. So, what is…if someone has a short cervix…oh, actually I should ask you, how do we define a short cervix? Like, what is short, and what is not short?
Dr. Gupta: Right. So, there’s kind of different standards that people use. They might use, like, a specific length, they might use, you know, the 10th percentile for gestational age. The standard that many people use, and what we use, is less than 2.5 centimeters.
Dr. Fox: Right. So, someone’s cervix is, you know, under that we’re gonna call it “short.” And if it’s longer, then we’ll call it normal. Obviously, there is a difference between someone who has 2.4 versus, you know, 0.4, right? Because those are both in the short category. But the 2.4 is clearly a better place to be than the 0.4. But that’s sort of the cut-off that a lot of people use. So, if we do see someone with a short cervix, what is the first treatment option that’s available?
Dr. Gupta: Right, so the first treatment option that’s available is vaginal progesterone. And I think, you know, when you are referring to the treatment options that are available, you know, for women who are pregnant with their first pregnancy, this is what we’re talking about. So, kind of finding out that vaginal progesterone can be given to a patient with a short cervix, and then that’s been shown to decrease the risk of having a pre-term delivery kind of changed how we approached screening many years ago.
Dr. Fox: Yeah, and the data is really solid. It just seems that in, you know, study after study, if someone has a short cervix, and you give them progesterone that’s done [SP] vaginally pretty much, you know, once a day, from the time it’s discovered, until either they deliver or they get to full term 36, 37 weeks, it lowers the chance. It doesn’t cure them. It doesn’t mean that they won’t deliver early, but it definitely lowers the chance from some percent to a lower percent. And again, not everyone with a short cervix is gonna deliver early. In fact, probably the majority won’t, but the risk is much higher than baseline, and the vaginal progesterone does seem to lower it closer to baseline back to where it should be, so to speak.
Dr. Gupta: Right. So, this has been one of the great things that’s kind of been discovered over the last few years. And as you said, it’s given vaginally. Women are recommended to use it every night, once a night, all the way up until, hopefully, they’re full term or 37 weeks.
Dr. Fox: Yeah, any side effects from it, or anything, you know, risks associated with it, people should watch out for if they’re prescribed vaginal progesterone?
Dr. Gupta: Right. So, the great part about vaginal progesterone is that because it’s not taken by mouth, it’s vaginal. The side effects are usually very, very minimal. Obviously, progesterone is a hormone. So, there can be some things that people report such as headaches, nausea, breast tenderness, things like that. But for most people, there’s minimal to no side effects. And there’s definitely been no side effects that have been shown to impact the baby or the pregnancy.
Dr. Fox: Right. And also, typically, this is being recommended in the second trimester, you know, 15 plus weeks. And so, number one, there does not seem to be any risk of birth defects with giving someone progesterone, but even if there were somehow some theoretical risks that we didn’t know about or something like that. It’s given after the baby is fully formed. So, it really shouldn’t have an impact on malformations or birth defects, which is great. All right. So, what else is available other than vaginal progesterone if someone has a short cervix?
Dr. Gupta: Right. So, the second thing that’s a possibility is something called a cerclage. And what a cerclage is, is it is a stitch that’s essentially put in around the cervix, or sewed in around the cervix to help keep it closed. And a cerclage is a surgical procedure, meaning women have to go into the hospital and have the surgical procedure performed under…or like regional anesthesia, then they usually go home the same day, but it is a surgery. And a cerclage is recommended for women who have a prior preterm delivery or in some cases, some other risk factor for a preterm delivery, and a short cervix.
So, it’s not recommended for everybody with a short cervix. It’s usually recommended for women with a prior preterm delivery and a short cervix. Or it’s recommended for women with a very, very short cervix or an open cervix.
Dr. Fox: Yeah, and we’ve recorded, and we’re gonna drop also an entirely separate podcast on cerclage because it’s a very complex topic that deserves its own discussion, and got its own discussion, actually. But I think just sort of, conceptually, you know, as an overview, what we’re saying is, you know, progesterone is something that there’s…it’s sort of there’s reward, and it’s pretty low risk. So, it’s something we’re much more likely to recommend to somebody. We’re gonna recommend it frequently, even past 24 weeks, for example. Maybe gestationally it’s just not as important because there aren’t a lot of circumstances where we’re, like, hesitant to prescribe vaginal progesterone. But for cerclage, it’s a much bigger deal, right? It’s a surgical intervention. It’s a lot more invasive, obviously. There’s a lot more potential repercussions.
And so, that’s something we really reserve for someone who we’re highly confident they need it. And that’s, you know, basically earlier in pregnancy versus history based on the cervix itself. So, it’s used less often, but it is a potential intervention for someone with a short cervix, particularly someone with a prior preterm birth, as you said, but even sometimes people without, there’s case by case basis where we might recommend it.
Now, as you said before, there are some people who don’t check the cervix after 24 weeks. And that’s usually because, historically, we wouldn’t place a cerclage past 24 weeks. And so, they sort of said, “All right, there’s no point in screening.” I always find it a little bit confusing why someone wouldn’t screen the cervix after 24 weeks when you can get vaginal progesterone after 24 weeks? And I haven’t really gotten a really good answer to that, from people who are more religious about stopping and checking the cervix at 24 weeks. I don’t know if you’ve heard any good ones.
Dr. Gupta: No, I mean, I didn’t get…you know, as you know, most of the studies on vaginal progesterone only enrolled women before 24 weeks. I think if we get some more data on women who use vaginal progesterone starting after 24 weeks, cervical length screening probably has a higher chance of being kind of more broadly used after that point.
Dr. Fox: Right. Now, talk to me about the pessary. Here’s where we really jump…we jump into the deep end of controversy here. Tell me about the pessary.
Dr. Gupta: So, a pessary is basically a plastic doughnut-shaped item. And it’s placed around the cervix kind of with this same idea as a cerclage. But instead of sewing a suture around the cervix, you actually just kind of put a little donut around the cervix to help keep it closed. The nice part about a pessary is we can just put it in an office. It takes a minute or two. It might be a little bit uncomfortable when we put it in, but then you don’t feel it at all. So, it essentially has almost basically no risk to the patient. The downside of it, is it just…the studies on it haven’t really…there haven’t been as many studies on it, especially compared to cerclage or vaginal progesterone. So, it might work. I think the data is still has to kind of show how well it works and in what circumstances, but it also has no risks. So, we usually start with vaginal progesterone or cerclage, if needed, or if we can, and kind of use the pessary as a backup option.
Dr. Fox: Yeah, what I found fascinating about pessary is it was not invented for women with a short cervix who are pregnant. It’s sort of like this is a secondary use. Do you wanna let our listeners in on why they were originally invented?
Dr. Gupta: Right. So, they were originally used for what’s called prolapse where either the uterus, or the bladder, or the rectal tissue was kind of coming out of the vagina. And so, it was used for comfort in that purpose. And then this is a secondary use of it.
Dr. Fox: Yeah, so when people are getting a pessary, they’re like, “Wait, that’s odd. I’m kind of young for that, aren’t I?” because usually, they’re in [SP] older women potentially who have, like you said, prolapse, and either aren’t candidates for surgery, or don’t want surgery, or you know, surgery might not work, or whatever it is. But it does seem to…it has been studied in pregnancy. And yeah, [inaudible 00:20:05] fascinating is, you know, when you look at the studies in pessary, it’s really all over the place. I mean, you read one study that looks like it was, you know, really well designed and a good study and done well, and it seems to work great. And then you look at another study that was also, you know, well designed, and it seems to not help at all.
And how to sort of reconcile that, that there’s, you know, studies that are both very good and seem to have, you know, everything you need to, you know, make a good study come to totally opposite conclusions. And this is one of the reasons this is really debated over whether it works or doesn’t work, and to what degree, and in whom. And all this and, like you said, we sort of have it as an adjunct treatment, but it’s not entirely clear exactly who it’s gonna help and to what degree. But again, fortunately, with pessary, the stakes are pretty low, because it’s not a particularly risky intervention. It’s not painful or anything like that.
Dr. Gupta: Exactly. And so, it’s an option that we have. For women who we do recommend the pessary, we place it, and then we hopefully take it out around 36 to 37 weeks, when we want a patient to go into labor after that point.
Dr. Fox: Now, what about things that are frequently recommended for someone with a short cervix? Like bed rest, for example, or not having sex? What do you do in that situation? How do you counsel women?
Dr. Gupta: This is definitely something also controversial. And I would say it’s something very kind of doctor-to-doctor specific, meaning all of us have our own opinions on this. I think, you know, many of us would agree that, in general, there’s not really any good data that shows that bedrest will decrease the risk of preterm delivery in a woman with a short cervix. So, in a kind of a broad sense, we usually do not recommend bed rest. And not only is there not really data recommending it, there’s also some data that says real full bed rest, where women are just kind of feel obligated to stay in bed all day is bad for the mother’s health. It increases their risk of blood clots in their legs or their lungs. And it also kind of deconditions them during pregnancy, which is not ideal.
So, in kind of a sense of true bedrest of not doing anything, the data says that’s not beneficial and could be risky for mom. On the other hand, I think many of us sometimes say, you know, for women who are very high risk for a preterm delivery, may be experiencing contractions or different physical discomforts. Many of us will tell them to kind of take things easy a little bit, regular day-to-day activities, and maybe not any very intense exercise or other things like that.
Dr. Fox: Yeah, I think this is one of the hardest things to talk about with people with a short cervix, because, you know, they’re looking for answers, right? They’re looking for us to tell them what to do. And I could do that, right, and it’s no sweat off my back to tell them what to do or what not to do. But it’s a little bit intellectually dishonest in a sense, because, like you said, I think most of us are pretty, you know, confident that it’s not a great idea to just lie in bed all day, for the next, you know, three months. So, there’s a lot of downside to that. And as far as we know, there doesn’t seem to be any upside.
On the other hand, we’re all a little bit skittish about saying, “Yeah, I continue to train for the marathon.” While you have a short cervix. Like, that just seems, like, not to be a good idea, even if I can’t prove it to you. And so, there’s probably some line in between those two extremes that’s appropriate. But we don’t know what it is. And we don’t know where it is. And we don’t know is it closer to the more bed-resti side, or the more activity side, and it’s also probably different for each person. And it’s hard to know exactly what to do.
What I generally tell people, and this is sort of as best as I could come up with, and it’s what I tell people, “Is the best I can tell you.” Is, you know, I say that that there’s some point in between, and I just tell people, they have to individualize it. Meaning, if they’re doing something that’s sort of normal activities, and they feel totally normal, perfectly fine, then it’s probably okay. Whereas if they sort of hit the point where they’re like, “All right, once I sort of exceed this amount, I start to feel crampy, I start to feel pressure, I just start to feel off, then it’s time to back off.”
And that amount is gonna differ for every person. I don’t know if that’s the best answer. I don’t know if it’s the right answer. But it seems to be the most reasonable one I could come up with to sort of help people figure out what to do in this circumstance. And obviously, some people are more strict than what I tell them, and they sort of stay in, you know, rest a little bit more, and other people are more lenient than what I tell them, and they, you know, work out a little bit more than…but I don’t know. I’m not sure how to exactly tell people what to do in that circumstance. It’s tough.
Dr. Gupta: It is tough, and I would agree with you that it is really specific for each patient or each woman. Meaning, you know, many women kind of know how their bodies are, and what makes them feel uncomfortable, or in pain, or different things. And so, many women are able to kind of individualize this for themselves, you know, within kind of some general guidelines that we’re able to give them.
Dr. Fox: Yeah, I mean, it sounds a little, you know, trite, but you know, listen to your body. It’s a real thing. It is a real thing.
Dr. Gupta: Right. Exactly. And women are good at it.
Dr. Fox: Yeah, no, I mean, yeah, I agree. And then what about with sex?
Dr. Gupta: Right. So, you know, for just a short cervix, again, sex has not been shown to increase your risk of preterm delivery. But there are some indications where we would recommend no intercourse. So, for example, if you have a cerclage in place, we recommend no intercourse because it can create bleeding. If you have a pessary in place, we recommend no intercourse. But just for a short cervix, there’s no data that shows that intercourse increases your risk of preterm delivery.
Dr. Fox: Yeah, that’s also a tough one, because it’s true. And I agree that there’s no data that having sex is gonna increase the risk of preterm delivery, but it does in many women increase contractions, and so, a lot of women will then go on to have contractions, and since they have a short cervix, it’s very concerning to them. And they may end up in the hospital getting checked for contractions. And so, it’s again, one of these things where either you could say, “You know what? Your cervix is under a certain length. It’s just not worth the risk. Don’t have sex, or try it, see how it goes. See if you have contractions or not and again, try to individualize it.” And there isn’t a perfect answer, and people disagree about this. But this probably, like with bedrest, is probably a different answer for each person.
Dr. Gupta: Right. I mean, I agree with that.
Dr. Fox: All right, so just as a review, we do cervical screening in everybody who’s pregnant, and I think most people around the country are doing it in some capacity. For our higher-risk patients, we just go straight to a transvaginal ultrasound, either once or serially over the course of the second, or maybe third trimester. Again, based on their exact circumstances and risk factors. And for those who are at sort of a more typical risk or a lower risk, we generally just look abdominally, and if it looks normal, then they’re good to go. And if it looks borderline or short, then we’ll go to trans-abdominal. And obviously, if someone comes in with specific complaints, you know, contractions or bleeding this, we’re gonna be checking the cervix, or doing a vaginal ultrasound, but we don’t call that screening, that’s a lot different. Screening is really someone who has no symptoms, and we’re just looking…just you know, looking without any specific indication at that time.
Dr. Gupta: Right. That’s exactly right.
Dr. Fox: Simi Gupta, thanks for coming back on the podcast. Great to have you. You don’t know it now, but we’re dropping your podcast back-to-back. So, this will be we’re gonna get a lot of Simi Gupta.
Dr. Gupta: Sounds like a plan. Great.
Dr. Fox: Thank you for listening to the “Healthful Woman” podcast. To learn more about our podcast, please visit our website at www.healthfulwoman.com. That’s H-E-A-L-T-H-F-U-L-W-O-M-A-N.com. If you have any questions about this podcast or any other topic you would like us to address, please feel free to email us at hw@healthfulwoman.com. Have a great day.
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