Fontan Circulation and Reproductive Health in a National Swedish Cohort

Every year, approximately 2000 children are born with congenital heart defects in Sweden. In a small percentage of these cases, the heart defects are so severe that they cannot be corrected to resemble or function like a healthy heart. Instead, these highly complex heart defects are operated on to establish "single-ventricle circulation," also known as Fontan circulation or TCPC circulation (total cavopulmonary connection). This means there is only one chamber in circulation, pumping blood into the body's main artery. To facilitate venous blood flow to the lungs for oxygenation and back to the heart chamber, high venous pressure and low resistance in the lung circulation are required.

This type of blood circulation can lead to severe complications later in life, including heart failure, low oxygen saturation, blood clot formation, liver cirrhosis, bleeding, protein-losing enteropathy, arrhythmias, and reduced physical capacity. In the Swedish registry for congenital heart defects, SWEDCON, over 230 patients with single-ventricle circulation are registered in the adult section.

Congenital heart defects affect career choices, family planning, and leisure activities. Questions regarding heredity and pregnancy are common. The severity of different heart defects varies and has varying degrees of impact on patients' daily lives. Pregnancy and childbirth exert significant stress on a woman and her body. Due to the increased metabolic needs of the fetus and the mother, hemodynamics change during a normal pregnancy, with approximately a 40-50% increase in cardiac output and plasma volume. Pregnancy is often well tolerated by women with congenital heart defects, but there might be an increased risk of complications associated with pregnancy and childbirth. Women with complex congenital heart defects have a higher risk of experiencing cardiovascular events during pregnancy compared to women with simpler congenital heart defects. There is also a greater risk of infertility for these women. The modified WHO classifications system (mWHO class I-IV) can be used to assess risk associated with pregnancy and childbirth for women with heart disease, where higher class is associated with increased morbidity and mortality. In Fontan circulation, the risk of complications during pregnancy is considered high if the woman is classified as mWHO III or IV. If a woman experiences complications due to Fontan circulation before pregnancy, she is classified as mWHO IV and will be discouraged from pregnancy due to a very high risk for both maternal and fetal complications. During pregnancy, there is an increased risk of arrhythmias, heart failure symptoms, and thrombosis. Miscarriage risk is high for women with Fontan circulation, and preterm delivery is common, often resulting in low birth weight for gestational age. There is also an increased risk of peripartum bleeding. It is recommended that patients with Fontan circulation have frequent check-ups during pregnancy and in the first weeks after delivery.

Some women with complex congenital heart defects choose not to undergo pregnancy due to their heart condition. Others choose to become pregnant despite being informed about the high risks and advice against pregnancy, which places high demands on the care and follow-up of these patients. How men with Fontan circulation perceive their parental abilities and the possibility of having children is poorly studied, as well as how a partner of a person with complex congenital heart defects thinks and reasons about parenthood.

The impact of Fontan circulation on reproductive health and fertility needs to be illuminated, and additional studies are required from both medical and psychosocial perspectives.

Cognitive impairment is common among patients with congenital heart defects but is likely an overlooked cause of long-term illness. Cognitive function and fatigue significantly affect all aspects of quality of life, including employment opportunities, educational level, and the ability to maintain meaningful social relationships, such as marriage. How this affects reproductive health is not fully understood.

Objective:

To study a large national population (n=200) of adults with Fontan circulation and their potential partners regarding.

• the prevalence and explanatory factors for sexual dysfunction and infertility in women and men with Fontan circulation (Study A).
• the outcomes of pregnancy, choice of delivery mode, and complications in patients with Fontan circulation (Study B).
• the experiences and perceptions of becoming parents among women (n=20) and men (n=20), as well as elucidate reasoning and family planning among women and men (n=20) who have not become parents (Study C).
• Investigate the prevalence and explanatory factors for (Sub-study D):
• Fatigue
• In-depth cognitive screening to describe specific cognitive functions such as auditory memory, visuospatial memory, attention, cognitive speed, and executive functions.

Work Plan The study is a national study involving six national centers: Gothenburg, Linköping, Lund, Stockholm, Umeå and Uppsala. Each participating center includes all patients with Fontan circulation. This involves approximately 200 patients and their potential partners.

In Sweden, there are an estimated 40,000 adults with congenital heart defects. We have a unique national register for congenital heart defects, The Swedish Registry of Congenital Heart Disease (SWEDCON), which started in the 1990s with Grown Up Congenital Heart disease (GUCH) and expanded in 2009 to include pediatric cardiology, heart interventions, and now fetal cardiology in congenital heart defects.

Design: Observational study.

The aim of this research is to gain more knowledge in an area that has been relatively underexplored, thus improving care for women and men with congenital heart defects. It is relatively common for women with congenital heart defects to avoid pregnancy due to their heart condition. In cases of aortic valve and/or pulmonary valve disease, Tetralogy of Fallot, and transposition of the great arteries, up to a third of women reported they did not want to have children because of their heart condition .

Therefore, there is significant patient benefit in conducting research among women and men with congenital heart defects. By gaining more knowledge in a new and relatively unexplored area, care can be improved, enabling these women to give birth if they wish without having to avoid it due to their chronic disabilities. Women with less complex heart disease and better functional status can also benefit from new knowledge and improved care, especially since there is a link between maternal congenital heart defects and lower birth weight in infants.