Fertility and pregnancy in the Fontan population

Abstract

Background

Women with a Fontan circulation are deemed at significantly increased risk of maternal morbidity and mortality during pregnancy. Publications describe a small number of pregnancies worldwide and a high rate of miscarriage. We compiled the experience of women enrolled in the Australia and New Zealand Fontan (ANZ) Registry with regard to menarche, contraceptive use, pregnancy advice and pregnancy outcomes.

Methods

Women within the ANZ Fontan Registry were contacted and asked to consent to receiving sequential questionnaires.

Results

156 women ≥ 18 years of age (including 4 deceased individuals) were identified, 101 women consented and 97 completed the initial questionnaire. Women were aged (median) 25 years (23–32); menarche occurred at a median 14 years (13–16). A wide variety of contraceptive methods was reported. 81% of women reported having received advice that pregnancy carried an increased risk or was inadvisable. Pregnancy was reported in a minority (n = 27). Miscarriage (42.5%) and termination (7.5%) accounted for half the pregnancy outcomes and the babies were born early (median 31.5 weeks) and small (median 1350 g). Maternal complications of bleeding, arrhythmia and heart failure were reported with no early maternal mortality.

Conclusions

In women with a Fontan circulation the fertility onset is delayed and pregnancy has a higher rate of miscarriage. Successful pregnancy resulted in small and premature babies. Significant maternal morbidity occurred. Whether pregnancy with its volume loading has an adverse effect on the long-term outcome of women with a single ventricle remains to be elucidated.

Introduction

A Fontan circulation represents the final common pathway for a number of complex cardiac congenital conditions and is unique for relying on a passive circulation where central venous pressure drives pulmonary blood flow and, consequently, cardiac output [1]. Unfortunately, even the pioneer of the procedure recognised its limitations stating, more than 20 years ago, that it “imposes a gradually declining functional capacity and premature late death after an initial period of often excellent palliation” [2]. Although this data pertain to outcomes of the early atriopulmonary connection approach and the surgical technique has since been revised, follow-up data suggests ongoing significant morbidity in this population [3]. In 2008, the Australia and New Zealand (ANZ) Fontan Registry was created in order to collect data on all children and adults with a Fontan circulation in these two countries. The aims of the study were to establish current cross sectional data on menstrual history, contraceptive use, medication and anticoagulation use as well as reported medical advice regarding pregnancy. If women had undergone a pregnancy, further information regarding complications and outcomes was sought, as possible.

Pregnancy is a physiological challenge and has been shown to cause measureable asymptomatic decrease in cardiac function [4] as well as appearing to contribute to worse clinical outcomes in a number of different cardiac pathologies [5], [6], [7]. The AHA Guidelines for Adults with Congenital Heart Disease have a Class I recommendation that all women with a Fontan operation need a comprehensive evaluation prior to proceeding with pregnancy, by a physician experienced in adult congenital heart disease (ACHD) [8]. The European Society of Cardiology Guidelines states that successful pregnancy is possible in selected patients with intensive monitoring [9]. The 2011 ESC Guidelines on the management of cardiovascular disease in pregnancy classify the Fontan circulation as WHO III for pregnancy risk; meaning that there is a significantly increased risk of maternal mortality or severe morbidity [10].

Additionally, the Fontan population is usually mildly cyanosed, a physiological state that may decrease fertility and results in more miscarriages [11], [12]. Warfarin is often prescribed as an anticoagulant, adding to the challenges of pregnancy management. Choice of contraceptive method needs to be balanced against the risks of contraceptive method failure and potential pregnancy. Pregnancy, if attained, appears to usually result in the premature delivery of a small-for-age baby. Maternal cardiac status can also be compromised, most commonly due to arrhythmias, but also secondary to deterioration in cardiac function [13].

Current data, worldwide, is small but suggests approximately a 50% pregnancy completion rate in this population [10].

We chose to explore fertility and pregnancy data within a Fontan population further via a series of questionnaire studies.