The Fontan procedure is performed as the final stage of palliation for patients with single-ventricle congenital heart diseases, such as tricuspid atresia, hypoplastic left-heart syndrome, or severely unbalanced atrioventricular canal defect. It creates a functional series circulation in which all pulmonary blood flow is derived from the systemic venous return that subsequently supplies ventricular preload in the absence of a subpulmonic pumping chamber. Since its inception in 1971, surgical advancement in the Fontan procedure has led to improved long-term outcomes, with transplant-free survival reaching 84% at 20 years.1Fontan F Baudet E. Surgical repair of tricuspid atresia.Thorax. 1971; 26: 240-248Crossref PubMed Scopus (2027) Google Scholar,2Khairy P Fernandes SM Mayer Jr., JE et al.Long-term survival, modes of death, and predictors of mortality in patients with Fontan surgery.Circulation. 2008; 117: 85-92Crossref PubMed Scopus (732) Google Scholar There are an estimated 28,000 adult patients with Fontan physiology alive worldwide, a population that is expected to double within 20 years.3Akintoye E Miranda WR Veldtman GR et al.National trends in Fontan operation and in-hospital outcomes in the USA.Heart. 2019; 105: 708-714Crossref PubMed Scopus (28) Google Scholar,4d'Udekem Y Iyengar AJ Galati JC et al.Redefining expectations of long-term survival after the Fontan procedure: Twenty-five years of follow-up from the entire population of Australia and New Zealand.Circulation. 2014; 130: S32-S38Crossref PubMed Scopus (386) Google Scholar Many of these patients are females of childbearing age, making pregnancy and childbirth in the parturient with Fontan physiology a reality.5Rychik J, Atz AM, Celermajer DS, et al. Evaluation and management of the child and adult with Fontan circulation: A scientific statement from the American Heart Association [e-pub ahead of print[. Circulation. doi: 10.1161/cir.0000000000000696. Accessed May 1, 2022.Google Scholar Notably, pregnancy and childbirth in patients with Fontan physiology place unique stress on an individual whose cardiac physiology already places them at high risk for multiorgan system complications, including cerebrovascular and thromboembolic events, heart failure, cyanosis, arrhythmias, and liver failure.4d'Udekem Y Iyengar AJ Galati JC et al.Redefining expectations of long-term survival after the Fontan procedure: Twenty-five years of follow-up from the entire population of Australia and New Zealand.Circulation. 2014; 130: S32-S38Crossref PubMed Scopus (386) Google Scholar,6Kutty S Jacobs ML Thompson WR et al.Fontan circulation of the next generation: Why it's necessary, what it might look like.J Am Heart Assoc. 2020; 9e013691Crossref Scopus (18) Google Scholar, 7Garcia Ropero A Baskar S Roos Hesselink JW et al.Pregnancy in women with a Fontan circulation: A systematic review of the literature.Circ Cardiovasc Qual Outcomes. 2018; 11e004575Crossref PubMed Scopus (43) Google Scholar, 8Dimopoulos K Diller GP Koltsida E et al.Prevalence, predictors, and prognostic value of renal dysfunction in adults with congenital heart disease.Circulation. 2008; 117: 2320-2328Crossref PubMed Scopus (281) Google Scholar, 9Khairy P Poirier N Mercier LA. Univentricular heart.Circulation. 2007; 115: 800-812Crossref PubMed Scopus (238) Google Scholar Although traditional pregnancy risk stratification scores categorically place parturients with Fontan physiology into a higher risk group, Fontan-specific guidelines do not exist for the peripartum period.10Canobbio MM Warnes CA Aboulhosn J et al.Management of pregnancy in patients with complex congenital heart disease: A scientific statement for healthcare professionals from the American Heart Association.Circulation. 2017; 135: e50-e87Crossref PubMed Scopus (202) Google Scholar, 11Regitz-Zagrosek V Roos-Hesselink JW Bauersachs J et al.2018 ESC Guidelines for the management of cardiovascular diseases during pregnancy.Eur Heart J. 2018; 39: 3165-3241Crossref PubMed Scopus (889) Google Scholar, 12Monteiro RS Dob DP Cauldwell MR et al.Anaesthetic management of parturients with univentricular congenital heart disease and the Fontan operation.Int J Obstet Anesth. 2016; 28: 83-91Abstract Full Text Full Text PDF PubMed Scopus (16) Google Scholar, 13Elkayam U Goland S Pieper PG et al.High-risk cardiac disease in pregnancy: Part I.J Am Coll Cardiol. 2016; 68: 396-410Crossref PubMed Scopus (143) Google Scholar This critical void is due largely to limited peripartum outcomes data for the parturient with Fontan physiology. In this case series, the authors developed a framework for the peripartum management of this challenging population, highlighting the need for team-based management of high-risk patients.14Davis MB Walsh MN. Cardio-obstetrics.Circ Cardiovasc Qual Outcomes. 2019; 12e005417Crossref PubMed Scopus (39) Google Scholar The authors conducted a retrospective, single-center case series of Fontan parturients ≥15 years who delivered a live birth infant at Vanderbilt University Medical Center between 1999 to 2020. The study was approved by the Vanderbilt University Institutional Review Board. A RedCAP database containing demographic and phenotypic data of adult patients with congenital heart disease cared for at the authors’ institution was queried for the pregnant patients with Fontan physiology during the study period.15Harris PA Taylor R Thielke R et al.Research electronic data capture (REDCap)–a metadata-driven methodology and workflow process for providing translational research informatics support.J Biomed Inform. 2009; 42: 377-381Crossref PubMed Scopus (22958) Google Scholar The females with incomplete records and those who were followed but ultimately delivered their infants at another institution were excluded (Fig 1). A chart review was performed by 3 independent reviewers and cumulative data were reviewed for accuracy. Twelve patients with Fontan physiology had a total of 19 pregnancies, resulting in live births that received care at Vanderbilt University Medical Center. Four patients who received prenatal care at Vanderbilt University Medical Center and ultimately delivered 6 live births at an outside hospital were excluded from the present study (Fig 1). Of the remaining 8 patients, there were a total of 13 live births. Three patients had >1 live birth during the authors’ study period. The mean maternal age at the time of delivery was 25 (range 18-33 years old). The baseline characteristics, anatomy, and details of the pregnancy are presented below in Table 1.Table 1Baseline Maternal CharacteristicsBirthsAge, yAnatomyFontan TypeShuntNYHAFailure PhenotypeLVEFAV Valve RegurgitationArrhythmiasExtra-Cardiac ComplicationsBaseline SaO2Anti-coagulation1A28DILV, left AV valve atresia, TGALTVV collaterals coiled; baffle leak*Right-to-left shunting.1FFrEF45%Mild-moderateYes (IART, Atrial flutter s/p RFA x2; VT s/p ICD, SA nodal dysfunction)None86%Yes (LMWH)1B32DILV, left AV valve atresia, TGALTVV collaterals coiled; baffle leak*Right-to-left shunting.2FFrEF35%Mild-moderateYes (IART, Atrial flutter s/p RFA x2; VT s/p ICD, SA nodal dysfunction)FALD88%Yes (LMWH)225DILV, L-TGAECNo1None50%TraceYes (Atrial tachycardia s/p RFA x2, CHB -> PPM)No95%No3A 3C18Tricuspid + pulmonary atresiaLTNo1NoneNone>55%MildMildNoneNone92%Yes (LMWH)†Indication for anticoagulation was Fontan thrombus.3B25Tricuspid + pulmonary atresiaLTNo1None>55%MildNoneNone96%Yes (LMWH)†Indication for anticoagulation was Fontan thrombus.3C27Tricuspid + pulmonary atresiaLTNo1None>55%MildNoneNone93%Yes (LMWH)†Indication for anticoagulation was Fontan thrombus.421DILVECNo2None>55%MildNoneNo90%No5A21Tricuspid atresiaLTPrior VV collaterals coiled; baffle leak*Right-to-left shunting.1NoneNoneNone>55%MildNoneNo92%No5B23Tricuspid atresiaLTPrior VV collaterals coiled; baffle leak*Right-to-left shunting.1None>55%MildNoneNo90%No5C25Tricuspid atresiaLTPrior VV collaterals coiled; baffle leak*Right-to-left shunting.1None>55%TrivialNoneNo95%No629DILV, severe PSLTNo1None>55%TrivialNoneNo91%No722DILV, TGA, large VSDLTNo1None>55%MildNoneNone93%No833Tricuspid atresia, ASD*Right-to-left shunting.APNo1None>55%MildNoneFALD (noncirrhotic)88%Yes (LMWH)Abbreviations: AP, atriopulmonary or “classic” Fontan; AV, atrioventricular; CHB, complete heart block; DILV, double-inlet left ventricle; EC, extracardiac Fontan; FALD, Fontan-associated liver disease; FFrEF, Fontan failure reduced ejection fraction; IART, intraatrial reentrant tachycardia; ICD, implantable cardioverter-defibrillator; LMWH, low-molecular- weight heparin; LT, lateral tunnel Fontan; NYHA, New York Heart Association; PPM, permanent pacemaker; PS, pulmonary stenosis; RFA, radiofrequency ablation; SaO2, Oxygen saturation in the arterial blood; TGA, transposition of the great arteries; VSD, ventricular septal defect; VT, ventricular tachycardia; VV, venovenous. Right-to-left shunting.† Indication for anticoagulation was Fontan thrombus. Open table in a new tab Abbreviations: AP, atriopulmonary or “classic” Fontan; AV, atrioventricular; CHB, complete heart block; DILV, double-inlet left ventricle; EC, extracardiac Fontan; FALD, Fontan-associated liver disease; FFrEF, Fontan failure reduced ejection fraction; IART, intraatrial reentrant tachycardia; ICD, implantable cardioverter-defibrillator; LMWH, low-molecular- weight heparin; LT, lateral tunnel Fontan; NYHA, New York Heart Association; PPM, permanent pacemaker; PS, pulmonary stenosis; RFA, radiofrequency ablation; SaO2, Oxygen saturation in the arterial blood; TGA, transposition of the great arteries; VSD, ventricular septal defect; VT, ventricular tachycardia; VV, venovenous. One patient had a classic atriopulmonary connection (12%), whereas 7 patients (88%) underwent contemporary-era surgical Fontan palliation with total cavopulmonary anastomosis—71% lateral tunnel and 29% extracardiac (Table 1). All of the parturients had a systemic left ventricle. The baseline systemic ventricular ejection fraction (EF) was assessed at a median of 27 (range 1-60) days prior to delivery. The majority of pregnancies (11/13, 85%) began with an asymptomatic (New York Heart Association class I) female free of Fontan failure at the time of conception. Fontan failure was defined as death, transplant, diagnosis of protein-losing enteropathy, predicted peak VO2 <50% on cardiopulmonary exercise testing, or new loop diuretic dependence persisting throughout the postpartum period.16Book WM Gerardin J Saraf A et al.Clinical phenotypes of Fontan failure: Implications for management.Congenit Heart Dis. 2016; 11: 296-308Crossref PubMed Scopus (75) Google Scholar,17Byrne RD Weingarten AJ Clark DE et al.More than the heart: Hepatic, renal, and cardiac dysfunction in adult Fontan patients.Congenit Heart Dis. 2019; 14: 765-771Crossref PubMed Scopus (9) Google Scholar Two pregnancies in the same patient began with Fontan failure with reduced EF at baseline. No patient had more than mild-moderate atrioventricular valve regurgitation at the start of pregnancy. Baseline arrhythmias (3/13, 23%) and hypoxemia (7/13, 54%) were common, and many received anticoagulation therapy (5/13, 38% of total pregnancies). Standard pregnancy risk scores classified all pregnancies as complex; 100% were World Health Organization class 3, whereas 77% were ZAHARA score 2.5 and 23% were ZAHARA score 4. Of the 13 deliveries, 77% were via caesarian section (C-section), and 23% were vaginal deliveries, all forceps-assisted. The majority of parturients delivered early (mean 35 weeks and 1 day), and 69% were preterm. Four (31%) deliveries were scheduled, whereas 9 (69%) were urgent. Of the scheduled cases, 2 (15%) were C-sections, and 2 (15%) were vaginal deliveries after a planned induction of labor (Table 1). Of the urgent cases, 38% were complicated by preterm labor, and 23% by premature rupture of membranes (Table 2). Ninety-two percent of parturients received epidural or combined spinal-epidural anesthesia (Table 3). The majority of parturients underwent invasive hemodynamic monitoring, with an arterial line (62%) placed prior to neuraxial blockade or general endotracheal anesthesia. One patient (8%) required intubation for a failed neuraxial blockade.Table 2Pregnancy ComplexityN, %WHO10203100%40ZAHARA2.5 (17.5%)77%4 (70%)23%HELLP0%PROM23%PTL38%C-section77%Abbreviations: HELLP, Hemolysis, Elevated Liver enzymes and Low Platelets; PROM, premature rupture of membranes; PTL, preterm labor; WHO, World Health Organization. Open table in a new tab Table 3Anesthetic, Mode of Delivery, Peripartum Management and Maternal OutcomeBirthsGestational AgeAnestheticMode of DeliveryUrgencyIndicationArt. LineUse of EphedrineUse of PhenylephrineICULOS, dPregnancy Complications (F, M)1A30.4EpiduralC-sectionUPTL, Nonreassuring fetal statusYesYesYesYes53FGR (F)Cyanosis, chorionic abruption (M)1B27.2GETA (after failed epidural)C-sectionUNonreassuring fetal statusYesYesYesYes36FGR (F)PPROM, chorioamnionitis, FFrEF (M)238.1EpiduralFAVDIOL at termGestational hypertensionNoNoNoNo3FGR (F)3A37.1EpiduralC-sectionUPlacental abruption, nonreassuring fetal statusNoNoNoNo7Placental abruption, cyanosis (M)3B35.6CSEC-sectionUPre-eclampsia, prior C-sectionYesNoNoYes7Severe pre-eclampsia (M)3C36.2CSEC-sectionUPre-eclampsia, prior C-sectionYesYesYesYes48Pre-eclampsia, placenta accreta requiring hysterectomy, PPH, POD1 CVA (M)436.2EpiduralC-sectionUBreech, PPROM, PTLNoNoYesNo4FGR (F)5A35.4EpiduralFAVDIOLPTLNoNoNoNo4Readmission for retained products of conception, PPH (M)5B37.3EpiduralC-sectionSPrior C-sectionYesNoYesNo5None5C35.1CSEC-sectionUMaternal chest pain, prior C-sectionYesNoYesNo5Increased palpitations and chest pain (M)633.1CSEC-sectionUNonreassuring fetal statusYesYesYesNo4FGR (F); Placental infarction (M)738.5EpiduralFAVDSNoNoNoNo4None834.6CSEC-sectionUPlacental abruptionNoNoYesNo9FGR (F), POD 1 TIA, cyanosis (M)Abbreviations: C-section, caesarean section; CSE, combined spinal-epidural; CVA, cerebrovascular accident; F, fetal; FAVD, forcep-assisted vaginal delivery; FFrEF, Fontan failure-reduced ejection fraction; FGR, fetal growth restriction; GETA, general endotracheal anesthesia; I, indicated; IOL, induction of labor; LOS, length of stay; M, maternal; PPH, postpartum hemorrhage; POD, postoperative day; PPROM, preterm premature rupture of membranes; PTL, preterm labor; S, scheduled; U, urgent. Open table in a new tab Abbreviations: HELLP, Hemolysis, Elevated Liver enzymes and Low Platelets; PROM, premature rupture of membranes; PTL, preterm labor; WHO, World Health Organization. Abbreviations: C-section, caesarean section; CSE, combined spinal-epidural; CVA, cerebrovascular accident; F, fetal; FAVD, forcep-assisted vaginal delivery; FFrEF, Fontan failure-reduced ejection fraction; FGR, fetal growth restriction; GETA, general endotracheal anesthesia; I, indicated; IOL, induction of labor; LOS, length of stay; M, maternal; PPH, postpartum hemorrhage; POD, postoperative day; PPROM, preterm premature rupture of membranes; PTL, preterm labor; S, scheduled; U, urgent. There was no maternal mortality in the peripartum period. However, 54% of pregnancies resulted in an acute complication in the peripartum period (Table 3; Fig 1)—2 pregnancies (15%) experienced a cerebrovascular accident (CVA) (including 1 patient receiving systemic anticoagulation at the time of the CVA), 2 pregnancies (15%) had worsening cyanosis resulting in prolonged hospitalization, and 1 pregnancy (8%) had worsening Fontan failure with reduced EF requiring intravenous (IV) diuretic therapy. In the authors’ cohort, 62% of pregnancies had a subsequent outpatient clinic visit with oxygen saturation in the arterial blood ≤92% within 1 week of delivery (Table 1). Two patients (15%) developed worsening hypoxemia during the peripartum period. Hypotension, defined as a decrease of systolic blood pressure >20% from baseline (15% of patients), was treated readily with intermittent doses of IV ephedrine and/or phenylephrine during the C-section in the presence of neuraxial blockade. No continuous vasoactive infusions were initiated in the peripartum period. For maternal complications, 23% of pregnancies were complicated by postpartum hemorrhage. Overall, the mean prepartum hemoglobin (Hgb) concentration was 13.0 g/dL (SD 1.8 g/dL) on admission to the hospital, whereas the mean Hgb at 24 hours postpartum was 10.5 g/dL (SD 1.64 g/dL). Transfusion was required only in 1 delivery (7.6%), when the patient received 2 units of packed red blood cells prior to the Hgb measurement at 24 hours postpartum. Only 33% of postpartum hemorrhage complications occurred in patients on chronic systemic anticoagulation. Maternal hemorrhage largely was due to placenta accreta, abruption, and placental infarction. One patient (8%) experienced maternal hemorrhage from retained products of conception. Preeclampsia occurred during 2 pregnancies (15%). The average hospital length of stay postpartum was 15 days (SD 16.3 days). Four patients (30%) were admitted to the intensive care unit for heart failure, hemorrhage, or CVA. The majority of neonates were born prematurely (69%; mean 35.1 weeks, IQR 34.8 - 37.1 weeks). Nearly half (46%) of births were complicated by fetal growth restriction, and 31% of infants were small for gestational age. The Apgar scores at 1 and 5 minutes were a mean of 6.7 and 7.8 (SD 2.75, 2.54), respectively. Fontan pregnancies are high-risk and require a multidisciplinary approach to management. Given the expected doubling of the Fontan population in the next 20 years,3Akintoye E Miranda WR Veldtman GR et al.National trends in Fontan operation and in-hospital outcomes in the USA.Heart. 2019; 105: 708-714Crossref PubMed Scopus (28) Google Scholar,4d'Udekem Y Iyengar AJ Galati JC et al.Redefining expectations of long-term survival after the Fontan procedure: Twenty-five years of follow-up from the entire population of Australia and New Zealand.Circulation. 2014; 130: S32-S38Crossref PubMed Scopus (386) Google Scholar the authors anticipate a surge of Fontan pregnancies requiring specialized centers of multidisciplinary experts with knowledge of the anatomy and physiology of both Fontan palliation and pregnancy for their management. Teams of adult congenital heart disease cardiologists, maternal-fetal medicine, obstetric anesthesiology, and cardiac anesthesiology are best equipped to optimize maternal health during Fontan pregnancy and to facilitate safe delivery. The considerations for Fontan pregnancy management are shown in Figure 3. Benjamin P. Frischhertz, MD; Adult Congenital Heart Disease, Cardiovascular Medicine, Vanderbilt University Medical Center, Nashville, TN, USA The major complications encountered in this case series in the peripartum period were hypoxemia, heart failure, and hemorrhage. The development of heart failure and cyanosis likely was associated with the cardiovascular stress of pregnancy, especially in the peripartum period. In the patients with normal cardiac physiology, the maternal cardiac output (CO) increases by 30% to 50%, driven by an increased preload from blood volume expansion in early gestation, followed by an increase in heart rate. This increase in CO peaks at approximately 24 weeks of estimated gestational age.18Sanghavi M Rutherford JD. Cardiovascular physiology of pregnancy.Circulation. 2014; 130: 1003-1008Crossref PubMed Scopus (421) Google Scholar,19Walker F. Pregnancy and the various forms of the Fontan circulation.Heart. 2007; 93: 152-154Crossref PubMed Scopus (25) Google Scholar The patients with Fontan physiology have a relatively fixed CO, with limited capacity to accommodate the increased blood volume associated with pregnancy.7Garcia Ropero A Baskar S Roos Hesselink JW et al.Pregnancy in women with a Fontan circulation: A systematic review of the literature.Circ Cardiovasc Qual Outcomes. 2018; 11e004575Crossref PubMed Scopus (43) Google Scholar,20Gewillig M Brown SC Eyskens B et al.The Fontan circulation: Who controls cardiac output?.Interact Cardiovasc Thorac Surg. 2010; 10: 428-433Crossref PubMed Scopus (205) Google Scholar,21Gewillig M Brown SC. The Fontan circulation after 45 years: Update in physiology.Heart. 2016; 102: 1081-1086Crossref PubMed Scopus (256) Google Scholar Pregnancy-induced anemia typically is mild and well-tolerated; however, in this patient population, it can further impair the oxygen-carrying capacity and contribute to the development of heart failure.7Garcia Ropero A Baskar S Roos Hesselink JW et al.Pregnancy in women with a Fontan circulation: A systematic review of the literature.Circ Cardiovasc Qual Outcomes. 2018; 11e004575Crossref PubMed Scopus (43) Google Scholar These normal physiologic changes of pregnancy may contribute to an increased risk of cardiovascular morbidity accompanying contemporary-era Fontan pregnancies in the setting of pulmonary blood flow without a subpulmonic pumping chamber.7Garcia Ropero A Baskar S Roos Hesselink JW et al.Pregnancy in women with a Fontan circulation: A systematic review of the literature.Circ Cardiovasc Qual Outcomes. 2018; 11e004575Crossref PubMed Scopus (43) Google Scholar,19Walker F. Pregnancy and the various forms of the Fontan circulation.Heart. 2007; 93: 152-154Crossref PubMed Scopus (25) Google Scholar,22Cohen AM Mulvein J. Obstetric anaesthetic management in a patient with the Fontan circulation.Br J Anaesth. 1994; 73: 252-255Abstract Full Text PDF PubMed Scopus (22) Google Scholar In the authors’ case series, systemic embolism was higher than other reports (15% v 1.7%), as was heart failure (8% v 3.9%), though comparisons were difficult due to the small sample size.7Garcia Ropero A Baskar S Roos Hesselink JW et al.Pregnancy in women with a Fontan circulation: A systematic review of the literature.Circ Cardiovasc Qual Outcomes. 2018; 11e004575Crossref PubMed Scopus (43) Google Scholar Jennifer Thompson, MD; Obstetrics and Gynecology, Vanderbilt University Medical Center, Nashville, TN, USA The patients with Fontan palliation often are prescribed chronic anticoagulation due to an increased risk of thrombotic complications and/or paradoxical embolism either related to arrhythmias, residual anatomic stumps, or fenestrations.10Canobbio MM Warnes CA Aboulhosn J et al.Management of pregnancy in patients with complex congenital heart disease: A scientific statement for healthcare professionals from the American Heart Association.Circulation. 2017; 135: e50-e87Crossref PubMed Scopus (202) Google Scholar,23Rodriguez FH Book WM. Management of the adult Fontan patient.Heart. 2020; 106: 105-110Crossref PubMed Scopus (12) Google Scholar In order to ameliorate the risk of maternal hemorrhage, the patients on chronic warfarin therapy should be converted to low-molecular-weight heparin (LMWH) throughout the pregnancy (and definitively by the third trimester for rare uses, such as doses <5 mg among mechanical valve patients).13Elkayam U Goland S Pieper PG et al.High-risk cardiac disease in pregnancy: Part I.J Am Coll Cardiol. 2016; 68: 396-410Crossref PubMed Scopus (143) Google Scholar Interestingly, only 33% of parturients with postpartum hemorrhage were on chronic anticoagulation therapy, which underscored the underlying placental insufficiency associated with Fontan physiology. Larger studies are warranted to determine whether systemic anticoagulation is associated with an increased risk of hemorrhage. Postpartum hemorrhage, defined by >1,000 mL blood loss during and within 24 hours of a C-section, was the most common peripartum obstetric complication seen in this case series, consistent with a prior study.7Garcia Ropero A Baskar S Roos Hesselink JW et al.Pregnancy in women with a Fontan circulation: A systematic review of the literature.Circ Cardiovasc Qual Outcomes. 2018; 11e004575Crossref PubMed Scopus (43) Google Scholar The patients with Fontan physiology are at increased risk for postpartum hemorrhage for a multitude of reasons, including liver dysfunction, elevated systemic venous pressure, decreased CO, thromboembolic disorders, and abnormal vascular malformations.7Garcia Ropero A Baskar S Roos Hesselink JW et al.Pregnancy in women with a Fontan circulation: A systematic review of the literature.Circ Cardiovasc Qual Outcomes. 2018; 11e004575Crossref PubMed Scopus (43) Google Scholar,24Gouton M Nizard J Patel M et al.Maternal and fetal outcomes of pregnancy with Fontan circulation: A multicentric observational study.Int J Cardiol. 2015; 187: 84-89Abstract Full Text Full Text PDF PubMed Scopus (63) Google Scholar The patients with Fontan physiology also have chronic hypoxic changes and poor placental blood flow.25Yokouchi-Konishi T Ohta-Ogo K Kamiya CA et al.Clinicopathologic study of placentas from women with a Fontan circulation.Circ J. 2021; 86: 138-146Crossref PubMed Scopus (3) Google Scholar In this case series, maternal hemorrhage occurred secondary to placental abruption, subchorionic hemorrhage, and 1 case of placenta accreta that resulted in an emergency hysterectomy (Table 3). Most of the deliveries were performed by C-section, often urgent due to nonreassuring fetal status and/or placental pathology (Table 3). Forceps-assisted delivery was employed for all of the patients who delivered vaginally in order to avoid the Valsalva-induced reduction in preload.10Canobbio MM Warnes CA Aboulhosn J et al.Management of pregnancy in patients with complex congenital heart disease: A scientific statement for healthcare professionals from the American Heart Association.Circulation. 2017; 135: e50-e87Crossref PubMed Scopus (202) Google Scholar Susan Eagle, MD; Anesthesiology, Vanderbilt University Medical Center, Nashville, TN, USA Fontan physiology is sensitive to changes in preload, contractility, and afterload, all of which may be affected acutely by pregnancy and by the administration of anesthetic agents. Without a subpulmonic ventricle, adequate preload to the single ventricle in patients with Fontan physiology depends on the transpulmonary gradient and the transpulmonary resistance. The transpulmonary gradient is a pressure difference between the central venous pressure and the common atrial pressure, and, thus, is dependent on systemic venous pressure, pulmonary vascular resistance (PVR), and single ventricular function. The CO in patients with Fontan physiology can be altered significantly with perturbation in any of these factors.26McLaughlin VV Shah SJ Souza R Humbert M. Management of pulmonary arterial hypertension.J Am Coll Cardiol. 2015; 65: 1976-1997Crossref PubMed Scopus (252) Google Scholar,27Gewillig M. The Fontan circulation.Heart. 2005; 91: 839-846Crossref PubMed Scopus (308) Google Scholar Decreases in preload, such as during neuraxial blockade or the administration of anesthetic agents that reduce systemic vascular resistance (SVR), can dramatically affect CO and impair end-organ perfusion. Mechanical ventilation with excessive tidal volume or positive end-expiratory pressure increases intrathoracic pressure, which can reduce preload and increase PVR, thereby reducing CO. Similarly, volatile anesthetics, such as sevoflurane and isoflurane, reduce SVR and may have negative inotropic effects on the systemic ventricle.22Cohen AM Mulvein J. Obstetric anaesthetic management in a patient with the Fontan circulation.Br J Anaesth. 1994; 73: 252-255Abstract Full Text PDF PubMed Scopus (22) Google Scholar,28Nayak S Booker PD. The Fontan circulation.EJA Educ. 2008; 8: 26-30Google Scholar During delivery, the anesthesiologist must be prepared for maternal hemorrhage in Fontan pregnancy, ensuring 2 large-bore peripheral IV catheters, fluid warming devices, and the availability of compatible blood products. The assessment of cardiac function with transthoracic echocardiography may be warranted, particularly during large-volume resuscitation and in patients with reduced systemic ventricular function. The filters placed on IV lines often inhibit fluid resuscitation and are not practical in the intraoperative setting. Thus, the anesthesiologist must thoroughly deair all IV access lines to prevent paradoxical air emboli (Fig 4). Neuraxial anesthesia, including combined spinal-epidural or epidural was employed in nearly every patient in this study (Table 3). Anticoagulation was discontinued for 24 hours prior to neuraxial blockade, according to the American Society of Regional Anesthesia and Pain Medicine guidelines.29Horlocker TT Vandermeuelen E Kopp SL et al.Regional anesthesia in the patient receiving antithrombotic or thrombolytic therapy: American Society of Regional Anesthesia and Pain Medicine Evidence-Based Guidelines (Fourth Edition).Reg Anesth Pain Med. 2018; 43: 263-309Crossref PubMed Scopus (389) Google Scholar In the event prophylactic LMWH was received within 12 hours or therapeutic LMWH within 24 hours of an urgent C-section, these authors would follow the American Society of Regional Anesthesia and Pain Medicine guidelines and initiate general anesthesia instead of neuraxial blockade. In this cohort, the patients receiving LMWH who underwent an urgent C-section had enough time lapse to safely receive neuraxial blockade. All of the patients received between 300-to-500 mL of IV crystalloid bolus prior to the neuraxial anesthetic to offset the expected decrease in preload, while avoiding the risk of congestive heart failure from excessive volume loading. Although neuraxial blockade often causes sympatholytic-induced bradycardia and hypotension, heart rate and blood pressure were maintained within 20% of baseline after neuraxial blockade with the modest use of phenylephrine and ephedrine (Table 3), without the need for vasoactive infusions. The authors preferred a neuraxial blockade to reduce the risks of intubation and mechanical ventilation (which place the patient at higher risk for aspiration and can reduce CO by reductions in preload and increases in PVR).10Canobbio MM Warnes CA Aboulhosn J et al.Management of pregnancy in patients with complex congenital heart disease: A scientific statement for healthcare professionals from the American Heart Association.Circulation. 2017; 135: e50-e87Crossref PubMed Scopus (202) Google Scholar,30Eagle SS Daves SM. The adult with Fontan physiology: Systematic approach to perioperative management for noncardiac surgery.J Cardiothorac Vasc Anesth. 2011; 25: 320-334Abstract Full Text Full Text PDF PubMed Scopus (28) Google Scholar The management of postpartum uterine atony may be complicated in patients with Fontan physiology due to the side effects of uterotonic agents, including a decrease in SVR, hypotension, and tachycardia.31Lee S CM Wendler R Cardiac effects of drugs used for induction of labour and prevention and treatment of postpartum hemorrhage.IJC Congenital Heart Disease. 2021; 5100208Google Scholar Oxytocin is used commonly as a first-line uterotonic agent, and was the uterotonic of choice in this case series. However, the side effects include systemic vasodilation and pulmonary vasoconstriction, creating a potentially deleterious physiologic state for patients with Fontan physiology. These effects are more pronounced when given as a bolus dose or with a rapid infusion. However, with a standard infusion rate of 10 U/h, these cardiovascular side effects are less pronounced and likely safe for mindful use in patients with Fontan physiology.32Bishop L Lansbury A English K. Adult congenital heart disease and pregnancy.BJA Educ. 2018; 18: 23-29Abstract Full Text Full Text PDF PubMed Scopus (4) Google Scholar,33Cauldwell M Swan L Uebing A et al.The management of third stage of labour in women with heart disease needs more attention.Int J Cardiol. 2016; 223: 23-24Abstract Full Text Full Text PDF PubMed Scopus (8) Google Scholar Notably, significant hemodynamic changes were not encountered with the use of oxytocin in this series. The tocolytic methylergonovine (Methergine) can cause hypertension and vasoconstriction, whereas 15-Methyl prostaglandin F2-alpha may cause systemic and pulmonary hypertension and bronchospasm, thus potentially decreasing pulmonary blood flow and CO in the parturient with Fontan physiology. Invasive blood pressure monitoring with an intraarterial catheter may be considered for the management of hemodynamic changes associated with anesthesia and/or postpartum hemorrhage in the parturients with Fontan physiology. Central venous catheters are not encouraged due to the risk of thrombosis or injury to the cavopulmonary anastomosis. If a central venous catheter is needed for inotropic support, these authors recommend the smallest size needed to achieve hemodynamic goals while avoiding thrombosis. All of the patients in this series were managed by a multidisciplinary team, including cardiac anesthesiologists. In recent years, the authors have added a director of perioperative congenital cardiac anesthesiology, who is trained in both adult and pediatric cardiac anesthesiology, to consult on all patients with congenital heart disease by 23 weeks of estimated gestational age. Information about each patient is relayed to the adult cardiac anesthesiology division. This additional safeguard is particularly beneficial for parturients who present acutely with preterm labor, hemorrhage, or Fontan failure. Angela Weingarten, MD, MSCI; Adult Congenital Heart Disease, Cardiovascular Medicine, Vanderbilt University Medical Center, Nashville, TN, USA Multidisciplinary care is crucial for minimizing hospital length of stay while providing appropriate monitoring of the parturient with Fontan physiology in the postpartum period. The majority of patients were hospitalized between 3-to-9 days after delivery, whereas other pregnancies resulted in hospitalization for >5 weeks. Notably, in the patients with repeat pregnancies, the hospital length of stay increased after each delivery. One cause of prolonged hospitalization was hypoxemia. In the patients with a well-functioning Fontan, the oxygen saturation in the arterial blood should be ≥92%, with a small right-to-left shunt from venous blood returning from the coronary sinus into the common atria. Hypoxemia in this patient cohort may herald failing Fontan physiology, including systemic ventricular failure, pulmonary embolism, venovenous collaterals, and right-to-left shunting through a Fontan fenestration. Acute heart failure and hospital-acquired pneumonia were the etiologies of hypoxemia in the postpartum period, with a return to baseline prior to hospital discharge. It was observed that acute-to-chronic heart failure occurred in the parturient with preexisting depressed systolic function of the single ventricle and a higher ZAHARA score on presentation (Tables 1 and 3). Cerebral vascular accidents from thromboembolic events also were a major source of morbidity in this cohort. The CVAs occurred in the patients both with and without chronic systemic anticoagulation therapy. However, given the propensity of thromboembolic events in patients with Fontan physiology and the resultant devastating effects, multidisciplinary planning of peripartum anticoagulation is of paramount importance. Finally, although the authors did not encounter acute peripartum arrhythmias in this cohort, other analyses of Fontan pregnancies found that arrhythmias were among the most common cardiovascular adverse events (present in ∼8.4% of Fontan pregnancies).7Garcia Ropero A Baskar S Roos Hesselink JW et al.Pregnancy in women with a Fontan circulation: A systematic review of the literature.Circ Cardiovasc Qual Outcomes. 2018; 11e004575Crossref PubMed Scopus (43) Google Scholar Therefore, providers should consider the risks and benefits of telemetry monitoring based on local availability during Fontan pregnancy hospitalization. Figure 4 summarizes key considerations for the anesthesiologist managing a Fontan pregnancy. Although contemporary-era management of high-risk pregnant patients with Fontan palliation can occur safely without peripartum mortality, there remains the risk of significant maternal and neonatal morbidity. In this case discussion, the authors outlined peripartum complications among a series of Fontan pregnancies at their center over a 20-year period, and reviewed multidisciplinary considerations for the peripartum management of the parturient with Fontan physiology. Specifically, these authors recommended the involvement of cardiac anesthesiologists from the antepartum through peripartum periods. Long-term follow-up of this unique patient population is warranted.