Pregnancy in a Fontan Patient: New Horizons in Medical and Surgical Fontan...

So next, we're gonna shift gears totally again. uh, and, uh, I'd like to introduce our adult congenital heart disease fellow, Doctor Anisa Chowdhury, and our pregnancy expert and, uh, pregnancy leader, Doctor Nicole Brown. Um, and, uh, they're gonna talk to us about a, uh, uh, a case of a young lady with a fontan. And uh pregnancy. So I look forward to your talk. Thank you, Dr. Veldman. So I'll do the first portion, which is the case presentation, and Dr. Brown will talk about some general principles managing these patients. So this is a case of a 21-year-old woman who was born to tricuspiddoresia, a large ventricular septal defect, detransposition of the great arteries, and a severe lung segment aortic coagation. She underwent a correctation repair, surgery, and PA banding at 2 days of life. The approach was an end to end anastomotic repair after a section of the coarc segment, as well as a left carotid to left subclavian artery, side to side anastomosis. At 6 weeks of age, she underwent a right modified Blaylock Thomas Tausig shunt. And then a bidirectional Glen operation at 6 months. She ultimately underwent a 20 millimeter extracardiac fontan at 4 years of age. Since then, the fenestration has spontaneously closed. She's also had trans catheter coil and vascular plugging of venous venous collaterals at approximately 10 years of age. Of note, both her fontan pressures and her left ventricular and diastolic pressure were normal on a 2006 cath with pressures of 12 millimeters and 5 millimeters mercury respectively. Uh, she was followed throughout childhood by a pediatric cardiologist and noted to be doing well at that point from a cardiac perspective. She was then lost to follow up from age 16 to 21 years of age until she presented pregnant in her first trimester, to an outside adult cardiologist. Uh, the, the cardiologist wisely stopped her lisinopril, uh, given its stratogenicity, and referred her to our clinic. Further evaluation revealed at that time that she had had 3 prior miscarriages. She was told to be on contraception using Depo-Provera, but only had 1 injection in the past 3 to 4 years. At baseline, she had NYHA class 2 to 3 dysmic symptoms, uh, short of breath, climbing one flight of stairs or walking 2 blocks, and she really had no change in her symptom profile during the first couple of trimesters of pregnancy. She had no prior history of arrhythmias and she had repeatedly expressed concern about a higher peripartum mortality via vaginal delivery, and this was obtained through a variety of internet browsing readings. On physical exam, she had a fairly unremarkable exam for an adult, Fontan. Her vital signs were unremarkable besides a low normal 02 satA and 92% on room air. Her body habitus was normal with a BMI of 29. She had no signs of volume overload on exam, no jugular venous distension, no S3, clear lungs, no edema. Um, as with other, uh, Mosfontan, she had a single S1 and S2, um, with a regular rate and rhythm. She was visibly gravid by the time she hit a second trimester. Her EKG here shows a low lying sinus rhythm versus an ectopic atrial rhythm, some poor restal R wave progression, but otherwise non-specific STT findings. I'll show you her echocardiogram. So she had a normal left ventricular size, but with mildly reduced systolic function. Her estimated LVEF was between 45 to 50%. Some trace mitral regurgitation, trace aortic insufficiency, but no evidence of aortic stenosis or left ventricular outflow tract obstruction. Is this echo pregnancy? This was her echo during her first trimester, and we've had subsequent ones on a near monthly basis, but you can vaguely see that she is a little bit. A function that's a little bit shy of normal. This is an equivalent of a 4 versus 5 chamber. This is her left ventricle, right ventricle with a very large ventricular septal defect connecting the two chambers, left atrium, and I apologize for the freezing nature of this echo. No evidence of aortic stenosis or LVOT obstruction and very trace aortic insufficiency. Her fontan, which is up here, was grossly unobstructed. Her metabolic profile is fairly unremarkable. Her CBC was notable for a very mild polycythemia with a hemoglobin of 17, indicative of probable intermittent desaturations likely to her from her venous collaterals, um, as we knew her fenestration had spontaneously closed. Her thrombophilia profile was unremarkable, but of note she has had a lupus anticoagulant antibody sent given her multiple prior miscarriages. We deemed her a WHO class 3 risk, uh, given the uh WHO risk stratification as she is a, a complex Fontan patient, which indicates that she has a significantly elevated risk of both maternal morbidity and mortality during the peripartum period and the remainder of pregnancy. Uh, but as Doctor Brown will discussed, the risks extend not only to her but also to her fetus. Um, in terms of management, we had started her on an aspirin, 162 mg daily. Since her thrombophilia profile was not that elevated, uh, we did not push for stronger anticoagulation. We kept her off the ACE inhibitor given the teratogenicity, and we considered starting a beta blocker if her LV function remained depressed on subsequent visits. She was ordered a fetal echocardiogram at 18 to 22 weeks, established in one of our joint cardiac maternal fetal medicine clinics and is seen on a monthly basis at this time. She's been doing well up through her 26 week gestational period. Uh, we had discussed the risks, risks versus benefits of a vaginal versus C-section delivery. Uh, we can send this polling question out and we will revisit it after Doctor Brown finishes her talk. So I really just want to go over some general principles about pregnancy and uh women with Fontan just as we've discussed the Fontan physiology being a multi-system disease. Um, there, it is true within women during pregnancy as well that we are monitoring for other things besides just their circulation. And um sorry, can we go? Uh, so we'll come back to the polling question near the end, um, so. Kind of this basic question to conceive or not to conceive, um, so as we discussed things so they improved survival, um, of these patients with modern technology and care, uh, these women want to know as they reach childbearing age, can I get pregnant? Should I get pregnant, and what are they gonna risk, what are the risks going to be to myself and to the fetus, um, um, and if they don't want to get pregnant yet or they're, or you think they're not medically appropriate to get pregnant, uh, what types of contraception are safe. So this is a a balancing act between, uh, managing the mother and managing uh the baby just as every pregnancy is, but I would say the balance is a little more delicate in someone who has a fontan and just to review, since I know there's a large number of pediatric cardiologists in the audience, um, some of the normal physiologic changes during pregnancy. I'm not gonna read through all these, but there are um significant changes that occur, um, normally even with a normal heart, normal circulation, including. Uh, decreased systemic vascular resistance, um, also decreased PVR, increase in heart rate. Uh, there's a drop in blood pressure mid-pregnancy that rises again, and significantly there's an increase in cardiac output by about 50% as well as an increase in blood volume by 25%. And then we can't forget the increased risk of thrombosis, which is about 6 times normal during pregnancy and as high as 11 times normal in the 1st 6 weeks postpartum. So graphically represented in a couple of, um, um, diagrams here. Uh, during delivery there's further changes, um, hemodynamically. So in labor without analgesia, um, cardiac output may increase by about 30% during each contraction, so a significant pain response. We think that with regional analgesia there is that is mitigated to some degree and so we always advocate for epidurals in our patients. Sorry. Going back in the second stage, which involves pushing the baby out, um, the cardiac input may increase further, and then in the third stage, which is delivery of the placenta, the cardiac output remains elevated, um, due to placental auto-transfusion and mobilization of some of the extracellular fluid. It really takes about 6 months for your cardiac output to return to non-pregnant levels postpartum. And so certainly, although we're following them in the early postpartum period, um, we follow them again at 6 months, um, to kind of ensure a return to baseline. Sorry, I'm scrolling backwards, but it seems to keep going the other direction. Um, so outcomes significantly miscarriage rate is actually very high, um, among Fontan single ventricle patients, um, about 46%, um, and the neonatal death rate is also elevated. We'll talk about, um, potential reasons why in a moment. Um, maternal deaths during pregnancy, however, are actually. Um, quite low, in fact, um, there's a manuscript sort of being, uh, worked on now that's a systematic review of multiple, um, cohort of studies that have, uh, smaller numbers, um, and in about 198 pregnancies and 110 women there are actually no deaths. So what we are most concerned about are the morbidity side of things more than the mortality in terms of the mother, um, so SVT occurring in about 8.9%, heart failure in about 5%, um, but with some wide range amongst the various studies, lesser risk of having embolism or needing pacing. Uh, we're also concerned from an obstetric standpoint about postpartum hemorrhage, um, and then from the terms of the fetus, uh, preterm delivery rates are quite high with most of these women delivering between about 26 and 36 weeks gestation, not quite making it to term, which would be 37 weeks. Uh, high rates of IUGR and small for gestational age, and then the risk of, uh, congenital heart disease in the fetus is probably somewhere between 3 to 10%. Um, that doesn't necessarily mean for single ventricle physiology, but for any type of congenital heart disease, whether it be PDA or BSD. So some of the, the broad categories that we classify these patients in are, um, the WHO classifications of pregnancy, and as, uh, Doctor Choudhury mentioned, uh, this, this, um, patient would actually land in C class 3. I just wanna specify though that, um, it actually says that significantly increased risk of maternal mortality or severe morbidity. So in this case, um, it's more the morbidity that we're concerned about, not the mortality in terms of the woman. Um, here's a list of some of the other things that we'd be classified in, in group 3. And I know you may not be able to read this slide, um, but this is, uh, from a recent pregnancy text called Pregnancy and Congenital Heart Disease just published this year. And again it shows that, uh, Fontan women will fall in Class 3. They should be followed, um, uh, in a multidisciplinary care unit, uh, with serial echocardiograms and a multidisciplinary team. And this diagram is really just to illustrate um one method of sort of separating out which fontans may be at higher risk than others so we all know all fontans are not created equally, um, so there's probably some way to classify them in terms of low, moderate, or high risk um as well and uh. Those that would be at higher risk would obviously be those who have had significant NYHA functional class deterioration prior to pregnancy, those who have a lot of residual cyanosis, pulmonary hypertension, arrhythmias, uh, multi-organ failure, or protein losing enteropathy. These are patients that you're probably really going to classify in class 4 and advise against pregnancy. So we really would like to meet with these patients in the preconception phase in a multidisciplinary clinic. That doesn't always happen, for instance, in this patient when she arrives 7 weeks pregnant after having been lost to fall for 5 years. So, um, this is a pregnancy is obviously a time when these patients can re-present to care, um, but we would do routine things, obviously exam and, and imaging, um, you know, in her case we would have liked to get a, uh, an MRI ahead of time given her correctation, but that wasn't able to be accomplished. So, um, we're following with echo, but thankfully she's had good function. Uh, a number of lab tests, um, preconception, you know, you might consider if, if you need to more accurately assess their hemodynamics with cath, but that's not absolutely required. And then certainly a review of medications both, uh, before pregnancy and if not before, then during early pregnancy to determine what needs to be stopped, um, address any potentially reversible or, um, modifiable risk factors such as arrhythmias, hemodynamic lesions that are residual, anemia, infections, and then discuss contraception. So in the antepartum care phase we are um doing intensive monitoring of these patients on up to about a monthly basis depending on how um how significant their disease is. Uh, we want to detect early and treat early for any complications that may occur, um, so it's important to have a highly specialized team. Um, there may be instances in which it's appropriate to offer termination for really high risk patients again addressing medications and, and following imaging and of course fetal echo, um, because of the high rate of congenital heart disease, um, in this patient population, the OBs will on their end be monitoring fetal growth and we will be on an ongoing, um, in an ongoing fashion discussing delivery mode, location, and timing. So there's some controversy in the general Fonte population that will be discussed a little bit more by Doctor Palumbo, I believe in the next segment, but, um, in the pregnancy, um, uh, pregnancy population. Um, you know, we have the same dilemma. Um, obviously warfarin is, uh, in the past been thought to be a big no no. I, I think still we, we are concerned about from an aspect of tragicity, especially in the first trimester. Um, aspirin seems reasonable for most patients, and this lady is on 162 mg. Uh, for those who might be at higher thrombotic risk because of arrhythmias, prior clot, etc. um, low cardiac output, you would probably consider something more, more therapeutic in terms of anticoagulation. Um, and then if people more in the moderate range, uh, potentially considering prophylactic dose, low molecular weight heparin. And then just keep in mind they're not going to deliver. It says 35 weeks, but many of them don't make it quite to be beyond 36. So you may wanna, you might want to even stop sooner, but, um, to consider stopping aspirin, and if they are on Coumadin, uh, that is at a low dose to stop that prior to 35 weeks. Um, we absolutely feel that in this scenario delivery should be at a tertiary care center, where the highest level of cardiac OB and anesthesia and neonatal care is available, um, making sure that all the team members are aware of the patient's status. Um, appropriate monitoring on a routine basis would include, uh, blood pressure, heart rate, rhythm, and pulse ox, plus and minus invasive blood pressure monitoring in rare circumstances. Um, it's better to have a woman on the left lateral decubitus position from the standpoint of, um, improving systemic venous return. And to keep her adequately hydrated, so we, we like to, um, starve and dehydrate women in pregnancy and delivery, but in Fontan patients it's not wise to let them get, uh, too dehydrated, uh, but at the same time want to avoid fluid overload. Compression stockings are a good idea and actually, uh, vaginal delivery with an epidural is the preferred method for most women from a cardiovascular perspective. Um, and then added, um, assistance to the second stage if needed. Uh, postpartum we take into account oxytocin in terms of uterine contraction and trying to use the lowest effective dose, uh, to avoid significant hemodynamic fluctuations. Um, we want to continue to monitor for arrhythmias, and I would plan for these women to stay in hospital for up to about a week, um, because that's really how long it takes for things to sort of settle back out, uh, and to be more out of the acute phase, um, and then obviously we want to make sure they're not lost to follow up after the delivery. So the last couple of slides here about contraception, which um should be the first thing you talk about, but postpartum also potentially the last thing you talk about. So in general we avoid estrogen containing contraceptives in, in women with uh fontan circulation because of the increased thrombogenicity. Um, laparoscopic tubal ligation, obviously, if they end up with a C-section, that's a simple thing to do. But if it requires a laparoscopic procedure later, um, keep in mind that, uh, the pneumoperitoneum required for that may be detrimental for these patients. Um, so here's a table you can refer to later for some acceptable forms of contraception. I would say my favorite would be probably, um, the subdermal implants, uh, being the lowest risk just requiring, um, uh, local anesthesia. And oops. So, um, this slide just to wrap up in conclusion that, um, pregnancy is possible in Fontan patients with appropriate management with a multidisciplinary team with, um, experience and, uh, referral to our tertiary care center, uh, and this is sort of the. The wide range of team members that we that participate in our our group and what we do is basically create a document when we see them in clinic that's to be available during delivery that includes their summary of their um their care and then some of the major risk factors um and then we break it down in antepartum labor and postpartum uh recommendations so easily accessible two page document. Thanks very much, Nicole. Um, uh, just as we're loading up the, the next talk, um, uh, because we've had such interesting discussion and, uh, and, uh, many questions coming in, and I think the subject material at hand has been important. Uh, has been very important in providing good care for, uh, for, uh, our patients. We have run short of time, and I don't think there's going to be enough time to deliver the last talk, but I think we will have, uh, enough time to do, uh, Doctor Palumbo's talk, which is on, on thrombophilia management. Um, but perhaps just a comment, uh, in relation to, uh, to anticoagulation in, in pregnancy, which is I think, you know, there's a wide spectrum of, of, of practice, and I think we definitely are on the extremely conservative end of only managing this lady with aspirin. And the dose of aspirin in her was based really on her aspirin resistance testing, uh, which is a crucial part of this. Um, and many people would use, of course, full anticoagulation, uh, by the very definition of Fontan's, but that then is associated with the whole risk of antepartum, postpartum hemorrhage. And so it's a real delicate balance to follow.