International Journal on Obstetrics and Gynecology (IJOG) | Skeena Publishers

Clinical Case Volume1-Issue2

Pregnancy in a Patient with a Fontan Surgery: Case Report and Review of the Literature

Ibargüengoitia Ochoa Francisco¹, Lira Plascencia Josefina², Sepúlveda Rivera Cintia María³, Ruiloba Portilla Francisco³, Gallardo Gómez Fabiola³*

¹Obstetrics Department at Instituto Nacional de Perinatología “Isidro Espinosa de los Reyes”, Mexico
²Adolescent Medicine Department. Instituto Nacional de Perinatología “Isidro Espinosa de los Reyes”, Mexico
³ObGyn Resident at Instituto Nacional de Perinatología “Isidro Espinosa de los Reyes”, Mexico
*Corresponding author: Gallardo Gómez Fabiola, ObGyn Resident at Instituto Nacional de Perinatología “Isidro Espinosa de los Reyes”, Mexico
Article History
Received: November 25, 2021 Accepted: December 16, 2021 Published: December 17, 2021
Citation: Francisco IO, Josefina LP, María SRC, et al. Pregnancy in a Patient with a Fontan Surgery: Case Report and Review of the Literature. Int. J.Obst & Gync. 2021;1(2):34‒36. DOI: 10.51626/ijog.2021.01.00006

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Abstract

Background: The Fontan procedure is performed as a palliative on patients with a complex congenital heart disease where there is no biventricular circulation. There is an increasing number of women who have undergone the procedure, reach the reproductive stage and become pregnant. The low cardiac output and flow in the Fontan circulation raises several issues during pregnancy.
Objective: To describe the case of a pregnant woman that underwent the Fontan procedure in her childhood.
Clinical case: We report the case of a woman who started prenatal care in our institution at 34 weeks of gestation with a history of Fontan’s procedure at 12 years of age. Her clinical, cardiological, laboratory, and fetal evaluation was satisfactory. At 37.3 weeks the pregnancy was electively terminated, and bilateral tubal occlusion was performed.
Conclusions: These cases suggest that patients with an adequate hemodynamic adaptation can have a pregnancy without long-term sequelae. However, it might be complicated by cardiac and obstetric events.

Keywords: Fontan procedure; Pregnancy

Introduction

Currently, most children with congenital heart disease survive to become adults. The Fontan procedure is a palliative strategy for children born with a single cardiac ventricle. It consists in channeling systemic venous return directly into the pulmonary circulation without the need for the ventricular pump to propel blood to the pulmonary vasculature [1]. These abnormal connections increase ventricular volume and unbalance pulmonary blood flow, creating changes that suppose a challenge to the cardiovascular system. There are several reproductive-aged women with this acquired physiology that become pregnant [2]. Pregnancy after a Fontan procedure carries a high perinatal risk. Guidelines state that it is associated with a significant risk of maternal morbidity including arrhythmias, thrombosis, heart failure and obstetric hemorrhage [3-8].

We hereby present the case of a patient with a history of surgical correction of a univentricular heart (Fontan procedure) in her childhood who was admitted to a third level center in Mexico with a 34-week pregnancy. The therapeutic plan and perinatal results are presented and discussed.

Methodology

A literature review of Fontan operation and pregnancy was performed; references were searched based on keywords (Fontan operation, Pregnancy) and effective information retrieval using available MeSH, through the Digital Medical Library. A total of 26 articles were found, four of which were excluded since their study population was children.

Clinical Case

A 28-year-old primigravid woman with a history of cyanogenic congenital heart disease that included pulmonary atresia, tricuspid atresia, ventricular septal defect, atrial septal defect, and persistent ductus arteriosus. At the age of 12 she underwent the fenestrated Fontan operation. She was sent to our institution at 34.0 weeks of gestation and was classified in NYHA functional class I since she did not present clinical cardiovascular decompensation.

On admission, the electrocardiogram showed sinus rhythm, the paraclinical studies were normal (hemoglobin 13.2g/dl and platelets 170k/µl.). Blood gases with oxygen of 64mm/Hg and oxygen saturation of 91%. The Doppler echocardiogram yielded an LVEF of 58%.

Her evolution was uneventful, and she remained in functional class I during pregnancy and the postnatal period. The last fetal ultrasonographic evaluation at 36.0 weeks reported estimated fetal weight in the 18th percentile with normal amniotic fluid. At 37.3 weeks an elective cesarean section was performed under peridural block. A live male product was obtained weighing 2435 grams and Apgar score of 8-9 at one and five minutes respectively. The trans-surgical hemorrhage was 200 ml. There were no anesthetic or surgical complications. Bilateral tubal occlusion was performed at the patient’s request. Thromboprophylaxis was managed with low molecular weight heparin during the puerperium. The postoperative evolution elapsed without complications both from the obstetric and cardiological point of view. Six months after pregnancy resolution the patient continued in functional class I with sinus rhythm.

Discussion

Patients born with single cardiac ventricle physiology who are candidates for Fontan surgery include: double outlet right ventricle, double inlet left ventricle, hypoplastic left heart syndrome, pulmonary atresia, severe Ebstein’s anomaly, tricuspid atresia and unbalanced atrioventricular canal [9].

Fontan surgery was first performed in 1968. On 1971 Fontan and Boudet published a series of three patients with bypass surgery [10]. Three possible Fontan circulations can be observed: atrio-pulmonary connection, atrio-ventricular connection and cavo-pulmonary connection. The latter became known as the new Fontan and has been the predominant version for the past 20 to 25 years [11]. The modern Fontan has two subtypes: the Fontan with lateral tunnel and the extra-cardiac Fontan. The modern Fontan can be accompanied by a fenestration which is a connection between the Fontan circuit and the right atrium [12] (Figure 1). Systemic venous blood is entirely directed outside the heart via a conduit connecting the inferior vena cava to the pulmonary artery. The physiology of the Fontan circulation results in venous congestion with elevated venous pressure and reduced ventricular preload with a chronic low output state. This can lead to reduced exercise tolerance, end-organ damage, and numerous complications [13]. For the best care of patients, it is important to understand the specific Fontan anatomy, the effects of pregnancy on Fontan circulation, and the effects of its physiology on perinatal outcomes.

Figure 1: Schematic of fenestrated Fontan surgery.
Pregnancy is characterized by a wide variety of physiological and hemodynamic changes, including an approximate 20% increase in heart rate; a doubling of cardiac output and plasma volume; a decrease in peripheral vascular resistance and blood pressure; and a hypercoagulable state. These lead to stress of the single functional ventricle, which may not be able to tolerate the increase in blood volume or the increase in cardiac output. Compression of the inferior vena cava which occurs in the pregnant state may compromise venous return in Fontan patients leading to predisposing hypotension. Several authors have published small case series of pregnant women with Fontan circulation [2,3,6,7,14].

Perinatal outcomes in 379 pregnancies have been reported as miscarriages 45-52%, preterm births 59-71%, small for gestational age fetuses 20-55%, and postpartum hemorrhage 14%.Women with congenital heart disease have a 3-8% risk of having a baby with heart disease. The main cardiovascular complications are supraventricular arrhythmias in the third trimester (8-11%), and heart failurein the third trimester and postpartum (3-13%) [2,6].

The high incidence of prematurity and small for gestational age fetuses may be due to a combination of factors such as placental insufficiency, poor hemodynamics due to limited cardiac output, neuro-hormonal environment, maternal medications, or iatrogenic errors in the decision to time the birth.

Given the high complication risk, these women need preconception counseling. However, there is little information on this subject [15]. During pregnancy the cardiologist should evaluate cardiac function at least every trimester with echocardiography and measurement of oxygen saturation to detect the presence of fluid overload and ventricular dysfunction. Hemoglobin levels should be checked regularly as well.

Prophylactic anticoagulation is recommended for pregnant Fontan patients with a history of arrhythmia or thrombotic events in the pre-gestational stage [16]. New developments in cardiac monitoring surveillance have made neuro-axial anesthesia the most common technique for patients with Fontan circulation [9]. During pregnancy resolution the patient should be monitored by electrocardiography, oximetry, and blood pressure. All women should have venous thrombosis prophylaxis after their cesarean section as well as reevaluation by the cardiology department 6 to 12 weeks after resolution.

There is little information regarding contraceptive practice in women after Fontan surgery. However, progesterone alone or subdermal implants are recommended; estrogens are contraindicated. Guidelines suggest counseling against pregnancy in the presence of oxygen saturation less than 85%, reduced ventricular function, moderate to severe atrioventricular regurgitation or failure, or presence of protein-losing enteropathy. The most recent European Society of Cardiology guidelines recommend avoiding pregnancy in any woman with Fontan circulation. However, despite being well informed about the potential risks, women may decide to continue the pregnancy if they desire.

Long-term results of Fontan surgery performed in patients with a low-risk profile show generally good outcomes. Chronic low flow conditions will result in widespread pulmonary vasoconstriction leading to failure of the entire circuit. Patients with Fontan failure may have a number of problems including early and late damage, decreased ability to exercise (50-60% of normal), ventricular dysfunction, dysrhythmias, cyanosis, hepatomegaly with secondary fibrosis, cirrhosis and hepatic carcinoma, lymphatic system failure resulting in protein-losing enteropathy and plastic bronchitis, venous thrombosis, ascites and peripheral edema [19,20]. Predicted survival at 20 years is 82%; the primary cause of late death is failure of the Fontan circulation21.

Conclusion

The published literature on pregnant women with a relatively functioning Fontan circulation suggests that pregnancy is generally well tolerated. Nonetheless, it continues to be a high-risk pregnancy where the potential morbidity is high and life-threatening; it should be managed in centers with multidisciplinary expertise in the fields of cardiology, high-risk obstetrics, cardiovascular anesthesiology and neonatology. By 2020, 70,000 Fontan surgeries have been performed worldwide, with 50% in women and an expected survival rate of 80% [22].

Conflicts of interest

The authors declare that they have no conflicts of interest.

References

Pregnancy in a Patient with a Fontan Surgery: Case Report and Review of the Literature

Ibargüengoitia Ochoa Francisco1, Lira Plascencia Josefina2, Sepúlveda Rivera Cintia María3, Ruiloba Portilla Francisco3, Gallardo Gómez Fabiola3*

Ibargüengoitia Ochoa Francisco¹, Lira Plascencia Josefina², Sepúlveda Rivera Cintia María³, Ruiloba Portilla Francisco³, Gallardo Gómez Fabiola³*