Pregnancy outcomes in patients with a fontan circulation and proposal for a risk-scoring system: single centre experience

Abstract

Background: Pregnancy in women with Fontan physiology poses a significant management challenge and is deemed high risk. The aim of this study is to describe short and long-term pregnancy outcomes in women who have undergone Fontan palliation and propose a novel risk-stratification model specific to women with a Fontan heart. Methods: We undertook a single-centre, retrospective cohort study of all female Fontan patients (n = 78) from 1991-2015. We recorded pregnancy outcome, maternal cardiovascular and obstetric complications and fetal outcome. We propose a risk stratification model to identify those women who might be at highest risk of adverse outcomes during pregnancy. Results: Twenty-one women had 55 pregnancies, with 13 (24%) live births and 38 (69%) spontaneous miscarriages (p < 0.001). Eight (62%) out of 13 live birth pregnancies incurred maternal cardiovascular complications and six (46%) experienced maternal obstetric complications. Median gestational age at delivery was 32(27-39) weeks with 12 out of 13 (92%) pregnancies resulting in pre-term delivery. There were more pregnancies (OR 4.90, 95% CI 1.46-16.42, p ≤ 0.01) and a trend towards a higher proportion of live births (OR 7.60, 95% CI 1.81-31.97, p = 0.06), in the 'lower risk' compared to those women in the 'very high risk' group. There were no maternal deaths. Conclusions: We observed a high first trimester miscarriage rate, significant maternal cardiovascular and obstetric complication rates and a high rate of pre-term births in pregnant Fontan women. Our risk stratification model requires further investigation but may identify those women at particularly high risk of a poor outcome, and inform realistic pre-pregnancy counselling.

Success in a Fontan pregnancy: how important is ventricular function?

“…Maternal risks include bleeding, arrhythmia, and heart failure but fetal loss is disproportionally high with reported rates of miscarriage from 27 to 69%, and small for gestation age infants and prematurity rates of up to 92%. [5][6][7][8][9][10] Poor fetal outcomes are thought to be due to a combination of cyanosis, anticoagulation, and suboptimal haemodynamics. [5][6][7][8][9][10] A recent risk stratification model divided patients into three risk groups: lower, intermediate, and very high, based on the functional class, ventricular function, exercise tolerance, oxygen saturations, and the presence or absence of atrioventricular valve regurgitation.…”

“…[5][6][7][8][9][10] A recent risk stratification model divided patients into three risk groups: lower, intermediate, and very high, based on the functional class, ventricular function, exercise tolerance, oxygen saturations, and the presence or absence of atrioventricular valve regurgitation. 9 Lower risk women had a trend towards a higher percentage of live births, but this was not significant. Clearly fetal outcome is more complex and not just dependent on the mother's functional state.…”

“…Poor fetal outcomes are thought to be due to a combination of cyanosis, anticoagulation, and suboptimal haemodynamics 5 10 A recent risk stratification model divided patients into three risk groups: lower, intermediate, and very high, based on the functional class, ventricular function, exercise tolerance, oxygen saturations, and the presence or absence of atrioventricular valve regurgitation 9 . Lower risk women had a trend towards a higher percentage of live births, but this was not significant.…”

Pregnancy in the FONTAN palliation: physiology, management and new insights from bioengineering

“…Both first and second trimester miscarriage is common, reported in 27-69% of cases [13,19,[22][23][24] and in those foetuses that survive, neonatal death is not uncommon, occurring in up to 5% live births [15]. This is likely to be due to prematurity in many cases, which affects up to 70-80% live births [11,13,19,22].…”

“…Pregnancy carries varying risks in women with congenital hearts defects even after successful repair. Preconception evaluation is essential for genetic consultation, identifying potential medical and surgical issues before pregnancy in order to improve outcomes [24].…”