Pregnancy in women with congenital heart disease: Specific lesions

INTRODUCTION — Risks associated with pregnancy in women with congenital heart disease affect both the mother and her fetus. The obstetrician and cardiologist are therefore responsible for the welfare of two patients.

The focus here is on management of pregnant women with specific congenital cardiac anomalies, both unrepaired and after reparative surgery. Other issues such as maternal risks, oxygen delivery, and management during labor and postpartum are discussed separately. (See "Pregnancy in women with congenital heart disease: General principles".)

Certain lesions such as coarctation of the aorta, tetralogy of Fallot, and Marfan syndrome are discussed elsewhere. (See "Heritable thoracic aortic diseases: Pregnancy and postpartum care" and "Management of coarctation of the aorta", section on 'Pregnancy' and "Tetralogy of Fallot (TOF): Long-term complications and follow-up after repair", section on 'Pregnancy'.)

Also covered separately are general cardiac issues concerning the management of arrhythmias, heart failure, valvular heart disease, and anticoagulation during pregnancy. (See "Supraventricular arrhythmias during pregnancy" and "Ventricular arrhythmias during pregnancy" and "Management of heart failure during pregnancy" and "Pregnancy and valve disease" and "Use of anticoagulants during pregnancy and postpartum".)

GENERAL MATERNAL AND FETAL RISKS — Reparative surgery has substantially increased the number of females with congenital heart disease who reach childbearing age. A study showed that the number of delivery hospitalizations with congenital heart disease increased significantly from 6.4 to 9 per 10,000 deliveries from 2000 to 2010 and that these deliveries had a greater than expected rate of medical and obstetric complications [1]. A review reported that congenital heart disease now comprises 80 percent of all pregnancies in women with heart conditions in the Western world [2]. Successful operation before gestation is pivotal in reducing maternal and fetal risks. The risks of pregnancy after congenital cardiac surgery are determined chiefly by the presence, type, and degree of cardiac and vascular residua and sequelae. One study of 229 pregnant patients with congenital heart disease suggested that prolonged labor was associated with increased odds of experiencing the composite cardiac outcome when compared with those who underwent a cesarean delivery without prolonged labor (30.8 versus 7.1 percent; odds ratio 6.8; 95% CI 1.4-32.5) [3]. The most common cardiac outcome was heart failure or volume overload requiring diuresis.

The 2018 American College of Cardiology/American Heart Association (ACC/AHA) guidelines for the management of adults with congenital heart disease, the 2018 European Society of Cardiology (ESC) guidelines for management of cardiovascular disease during pregnancy, and the 2020 ESC guidelines for the management of adult congenital heart disease included pregnancy recommendations for various cardiac lesions [4-6]. In 2017, the AHA published a scientific statement on the management of pregnancy in patients with complex congenital heart disease [7]. Women with congenital heart disease are advised to consult an adult congenital heart disease specialist for a risk assessment and counseling prior to conception. The management plan should include management during pregnancy, labor, and the postpartum period.

In women with congenital heart disease, the risks of pregnancy to mother and fetus are related to the severity of the heart disease. These issues are described in detail elsewhere. (See "Pregnancy in women with congenital heart disease: General principles", section on 'Fetal risk' and "Pregnancy in women with congenital heart disease: General principles", section on 'Individual risk factors'.)

The risk of specific lesions to the fetus is discussed in appropriate sections below [8]. The fetal risk of heritability of congenital heart disease is presented separately. (See "Pregnancy in women with congenital heart disease: General principles", section on 'Inheritance'.)

INTRACARDIAC SHUNTS — The major unoperated left-to-right intracardiac shunts that permit survival to childbearing age are ostium secundum atrial septal defect (ASD) (figure 1) and ventricular septal defect (VSD) (figure 2).

Ostium secundum ASD — Longevity in patients with an unoperated ostium secundum ASD spans the reproductive years. ASD is the most common repaired or unrepaired lesion in pregnant women with congenital heart disease. Issues related to pregnancy in women with ostium secundum ASD are discussed separately. (See "Management of atrial septal defects in adults".)

Ventricular septal defect — Pregnancy in women with repaired or unrepaired VSDs are discussed separately. (See "Management and prognosis of congenital ventricular septal defect in adults", section on 'Management of pregnancy'.)

Atrioventricular septal defect — Pregnancy in women with atrioventricular septal defects is discussed separately. (See "Management and prognosis of congenital ventricular septal defect in adults", section on 'Management of pregnancy'.)

Cyanotic congenital heart disease — Cyanotic congenital lesions include unrepaired tetralogy of Fallot, pulmonary atresia with aorto-pulmonary collaterals, some single ventricular lesions, tricuspid atresia, Ebstein anomaly with right-to-left shunts via an ASD, and congenitally corrected transposition of the great arteries with VSD or ASD [9].

A literature review reported the following complication rates during completed pregnancies (>20 weeks gestation) among women with palliated or unrepaired cyanotic congenital heart disease [8]:

●Maternal arrhythmias occurred in 3 of 63 pregnancies, heart failure in 14 of 74 pregnancies, and other cardiovascular events in 3 of 74 pregnancies.

●Preterm delivery occurred in 33 of 74 pregnancies (45 percent), fetal mortality in 9 of 74 pregnancies (12 percent), the peri-natal mortality rate was 4 percent (3 of 74 pregnancies), and the rate of recurrence of congenital heart disease of any type in offspring was 7 percent (5 of 68). (See "Pregnancy in women with congenital heart disease: General principles", section on 'Inheritance'.)

The above data included only pregnancies that reached at least 20 weeks gestation. In a review of 96 pregnancies in 44 women with cyanotic congenital heart disease, the live birth rate was 43 percent, and was strongly related to both the hematocrit and arterial oxygen saturation [9]. A successful pregnancy was unlikely if the maternal hemoglobin was ≥20 g/dL (live birth rate of 8 percent) or the maternal arterial oxygen saturation was ≤85 percent (live birth rate of 12 percent).

PATENT DUCTUS ARTERIOSUS — Pregnancy in women with a PDA is discussed separately. (See "Clinical manifestations and diagnosis of patent ductus arteriosus (PDA) in term infants, children, and adults", section on 'Complications during pregnancy'.)

EISENMENGER SYNDROME — Eisenmenger syndrome can occur with unrepaired ASD, VSD, PDA, or more complex cardiac lesions when progressive pulmonary vascular disease leads to intracardiac shunt reversal or bidirectional shunting (figure 3). Regardless of etiology, pregnancy in the Eisenmenger syndrome is associated with major morbidity and mortality. Issues related to pregnancy in women with Eisenmenger syndrome are discussed separately. (See "Pulmonary hypertension with congenital heart disease: Pregnancy and contraception".)

CONGENITAL AORTIC DISEASE — Pregnancy in women with coarctation of the aorta and aortopathy related a bicuspid aortic valve or Marfan syndrome are discussed separately. (See "Bicuspid aortic valve: Management during pregnancy" and "Heritable thoracic aortic diseases: Pregnancy and postpartum care" and "Management of coarctation of the aorta", section on 'Pregnancy'.)

UNCOMMON CONGENITAL CARDIAC DEFECTS IN PREGNANT WOMEN — There are several uncommon congenital cardiac defects that permit high probability of survival into reproductive age. Individuals with these lesions require individualized assessment by an expert in adult congenital heart disease.

Complete heart block — Complete heart block can be congenital or acquired. The congenital form, sometimes called the neonatal lupus syndrome, is presumed to result from trans-placental passage of maternal anti-Ro/SSA and anti-La/SSB antibodies. Approximately 50 percent of patients with congenital complete heart block are female and anticipate survival into childbearing age. Asymptomatic young women with congenital complete heart block and no pacemaker generally experience uneventful pregnancies, provided that the QRS duration is not prolonged (ie, the escape rhythm is junctional and not infranodal) and ventricular function is normal, which is usually the case. However, syncopal episodes occasionally first occur during gestation and the heart and circulation may not respond adequately to the acute circulatory demands of labor and delivery [10].

Ebstein anomaly — Issues related to pregnancy in women with Ebstein anomaly are discussed separately. (See "Ebstein anomaly: Clinical manifestations and diagnosis".)

Congenitally corrected transposition of the great arteries — This malformation, also called L-transposition of the great arteries (L-TGA), or atrioventricular, ventriculoarterial discordance, or double discordance, is characterized by inversion of the ventricles, which is countered (corrected) by ventriculo-great arterial discordance. The double discordance "corrects" the circulation because systemic venous blood moves from the right atrium to the pulmonary artery, but via a morphologic left ventricle; pulmonary venous blood moves from the left atrium to the aorta via a morphologic right ventricle. The long-term functional durability of a morphologic right ventricle in the subaortic systemic location is problematic, and high-degree heart block occurs at a rate of approximately 2 percent per year. Clinical manifestations and disease course are heterogeneous. Nearly all patients with L-TGA have associated anomalies such as systemic atrioventricular valve abnormality in 90 percent, VSD in most, and pulmonic stenosis (often subvalvular) in 40 percent [11].

The vulnerability of the morphologic subaortic right ventricle to hemodynamic overload, atrioventricular valve regurgitation, the development of heart failure [12], and the risk of heart block make pregnancy problematic. However, a literature review of studies published between 1985 and 2007 found the following complication rates during completed pregnancies (>20 weeks gestation) among women with L-TGA [8]:

●With respect to the mother, arrhythmias occurred in 3 of 84 pregnancies, heart failure in 6 of 84 pregnancies, and cardiovascular events in 2 of 84 pregnancies.

●With respect to the fetus, preterm delivery occurred in 7 of 78 pregnancies, fetal mortality in 1 of 78 pregnancies, perinatal mortality in 0 of 78 pregnancies, and recurrent congenital heart disease (of any type) in 1 of 28 pregnancies.

Data are not yet available regarding the degree of RV dysfunction that imposes a higher pregnancy risk in this patient population.

D-Transposition of the great arteries — Women with complete transposition of the great arteries are reaching reproductive age because of operative intervention initially involving atrial switch repairs, such as the Mustard or Senning procedure [13]. Gestational risks after Mustard or Senning repairs are related chiefly to the functional status of the subaortic morphologic right ventricle, to the level of pulmonary arterial pressure, and to conduction and rhythm abnormalities.

Since 1982, the arterial switch operation (Jatene) has been used increasingly to repair D-TGA in infancy [14-16]. Successful pregnancy has been reported among patients who have had successful arterial switch procedures [17].

The above cited literature review disclosed the rates of complications during completed pregnancies (>20 weeks gestation) among women with D-transposition (atrial switch repair except for three arterial switch patients) [8]:

●Maternal arrhythmias occurred in 27 of 173 pregnancies (15.6 percent), heart failure in 19 of 176 pregnancies (10.8 percent), and cardiovascular events in 4 of 178 pregnancies (2.2 percent). The rate of preeclampsia was higher than expected (10 percent versus 2 to 3 percent).

●With respect to the fetus, preterm delivery occurred in 43 of 126 pregnancies (34.1 percent), fetal mortality in 5 of 179 pregnancies (2.8 percent), perinatal mortality in 2 of 179 pregnancies (1.1 percent) and recurrent congenital heart disease (of any type) in offspring in 1 of 176 pregnancies (0.6 percent).

A retrospective study of 34 pregnancies in 21 women with atrial switch repair compared with nonpregnant controls with the same repair showed that cardiac events are equally common in both groups but that pregnancy was associated with worsening atrioventricular valve regurgitation [18]. Thirty-eight percent of the babies were born premature and 38 percent were small for gestational age. A review of this and other observational data suggested that the hemodynamic stress of pregnancy may have adverse late effects on the heart, including worsening functional class and atrioventricular valve regurgitation [19].

A retrospective study examined cardiac events during 17 pregnancies in nine women who had undergone an arterial switch operation; six women had clinically important valve or ventricular lesions before the index pregnancy [20]. Two women developed cardiac complications (nonsustained ventricular tachycardia and mechanical valve thrombosis) during the peripartum period [20]. Of note, this early cohort of patients with arterial switch operation had more complex cardiac disease than typical in later cohorts.

A later study from Australia presented outcomes of 17 successful pregnancies in 11 women after arterial switch surgery. There were two cardiac complications, including progressive aortic regurgitation and atrial flutter/fibrillation, one neonatal complication, and 10 maternal obstetric complications. LV function was unchanged postpartum [21]. A study from Japan of 14 successful pregnancies in 10 women reported that maternal cardiovascular events occurred in four patients (heart failure and arrhythmias in three and arrhythmia in one) [22]. On follow-up, there was no deterioration in functional class or LV function.

The ROPAC investigators reported on pregnancy and fetal outcomes in 41 women after arterial switch operations. There was no maternal mortality. Adverse events (heart failure and ventricular tachycardia) occurred in 4.9 percent. Fetal complications included prematurity (17.1 percent) and low birth weight (14.6 percent), with one fetal death (2.4 percent) [23].

The predictors of increased risk have not yet been defined, although the degree of systemic RV dysfunction may play an important role.

Single ventricle, unrepaired — A single ventricle or univentricular heart is a complex congenital cardiac defect with anatomic features that are not amenable to a biventricular repair and include hypoplasia of one ventricle, atresia of an atrioventricular valve, double inlet ventricle, double outlet ventricle with a remote ventricular septal defect, or an unbalanced atrioventricular canal [24]. In the majority of cases, the ventricular compartment has features of a morphologic left ventricle, and incorporates at its base a rudimentary outlet chamber that gives rise to the aorta, whereas the pulmonary trunk originates from the main ventricular compartment. Unrepaired adult patients may have anatomy unsuitable for palliation, or were not felt to be repairable in childhood.

Patients who reach adulthood have either pulmonary stenosis or pulmonary vascular disease that permits adequate, but not excessive pulmonary blood flow. There are a few reports of successful pregnancies with single ventricle and pulmonary stenosis [25-28], but pulmonary vascular disease carries the expected high gestational risk associated with Eisenmenger syndrome. (See 'Eisenmenger syndrome' above and "Pulmonary hypertension with congenital heart disease: Pregnancy and contraception".)

Tricuspid atresia — Tricuspid atresia is a type of functional single ventricle. In patients with tricuspid atresia, systemic venous return cannot reach the right ventricle directly because of an imperforate right atrioventricular (tricuspid) valve. Instead, systemic venous return traverses the atrial septum from a morphologic right atrium into a morphologic left atrium, and mixes with pulmonary venous return before crossing a solitary left atrioventricular (mitral) valve that connects the left atrium to the left ventricle [24].

In the usual form of tricuspid atresia, there is ventriculo-great arterial concordance (non-transposed). A restrictive ventricular septal defect constitutes subpulmonary stenosis. Sporadic unoperated survivors have been reported from the second through the fifth decades.

Successful pregnancy is rare but not unknown in unrepaired tricuspid atresia [29,30]. Normal pregnancies have been experienced after a successful Fontan procedure, but the risk of preterm delivery may be increased [31,32].

Repaired functional single ventricle — Pregnancy in patients with prior Fontan operation for single ventricle is considered high risk. The management and special considerations for this group of patients have been reviewed by Wolfe and colleagues [33] and by Wichett-Schmitt and colleagues [34]. This topic is discussed separately. (See "Overview of the management and prognosis of patients with Fontan circulation", section on 'Reproductive issues'.)

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Congenital heart disease in adults" and "Society guideline links: Management of cardiovascular diseases during pregnancy".)

SUMMARY AND RECOMMENDATIONS

●Pregnancy in congenital heart disease affects the mother and her fetus. The obstetrician and cardiologist are therefore responsible for the welfare of two patients. (See 'General maternal and fetal risks' above.)

●Given the heterogeneity of diseases, individual assessment and appropriate counseling by an adult congenital heart disease specialist is recommended for women with congenital heart disease who are contemplating pregnancy. (See 'General maternal and fetal risks' above.)

●Reparative surgery has substantially increased the number of females with congenital heart disease who reach childbearing age. Successful operation before gestation is pivotal in reducing maternal and fetal risks. The risks of pregnancy after surgery are determined chiefly by the presence, type, and degree of cardiac and vascular residua and sequelae. (See 'General maternal and fetal risks' above.)

ACKNOWLEDGMENT — The UpToDate editorial staff thanks Thomas P. Graham, Jr, MD, Michael R. Foley, MD, and the late Joseph K Perloff, MD, for their contributions to previous versions of this topic review.