In childhood, there is no evidence to suggest that gender influences survival [3]. In adulthood, there may be gender-related factors contributing to mortality differences. The Dutch CONgenital CORvitia (CONCOR) registry and the national mortality registry, as reviewed by Verheugt et al. [7], demonstrates 2.8 % of patients with ACHD died at a median age of 48.8 years, 42 % of whom were female, which is significantly greater than the general Dutch population. The majority of patients died from cardiovascular causes, primarily chronic heart failure and sudden death. Defects with the highest mortality were single ventricle lesions, tricuspid atresia, and double outlet right ventricle. Complications, including endocarditis, supraventricular and ventricular arrhythmias, conduction disturbances, myocardial infarction and pulmonary hypertension, were all associated with increased risk of mortality. All-cause and cardiovascular mortality was slightly higher in men, although this was not significant. Patients with Eisenmenger were found to have a small, although not significant, predominance in women [3]. Verheugt et al. [3] also report a lower female mortality in patients with coarctation of the aorta or aortic valve-related problems, which is primarily explained by the male predominance in these diseases.

The European Heart Survey database, as reviewed by Engelfriet and Mulder [8], demonstrates higher 5-year mortality in men over women, which appears particularly so in certain diagnoses: TGA, single ventricle anatomy status-post Fontan procedure (original procedure named after Francis Fontan), and cyanotic patients. Conversely, there was a greater mortality in women with Eisenmenger compared to men with Eisenmenger. Neither of these findings though were found to be statistically significant, perhaps due to the relatively low number of deaths.

Before the age of 40, women with Eisenmenger are more likely to die compared to men with Eisenmenger [5]. There is speculation regarding factors associated with mortality as reported by Jane Somerville [5]. Somerville lists that these factors may include effects of pregnancy, gynecologic surgeries with associated complications, cerebral abscesses, hormone-related fluid retention and a female predisposition to thrombosis, particularly in patients where oral contraception is being prescribed.

Although research is limited, women have been shown to be at a higher risk for certain outcomes and sequelae compared to their male counterparts. Verheugt et al. [3] and Somerville [5] report women with ACHD are at higher risk than men with ACHD of developing pulmonary hypertension. Pulmonary arterial hypertension, defined as mean pulmonary pressure greater than 25 mmHg at rest or 30 mmHg during exercise [9], is seen in 33–35 % more women [3, 10]. Eisenmenger physiology is characterized by severe, irreversible pulmonary arterial hypertension with resultant cyanosis [9]. There is speculation that puberty effects play a role in development of pulmonary arterial hypertension in women, as do hormonal differences between genders and pregnancy effects [3, 10]. There is potential that specific diagnoses, those more often seen in women, may contribute to the higher risk of pulmonary hypertension; however, ventricular septal defects (VSD), which do not have gender predominance, are more common in patients with Eisenmenger physiology compared to ASD for which there is a higher female predominance. The female predominance in pulmonary hypertensive patients decreases after the age of 40 [5]. This may be explained by the increased mortality in female Eisenmenger patients seen between the ages of 20–39 [5].

Among patients with congenital aortic pathology, women are at approximately 30 % lower risk of aortic complications or long-term sequelae, including dissection, surgery, and aneurysm formation, compared to their male counterparts [3, 8]. This is primarily explained by the greater male predominance in congenital aortic valve and outflow disease [3, 5, 6, 8, 10]. Surgical intervention is more likely in men based on the overall smaller size of the aorta in women and lack of gender-specific criteria for aortic surgery [3]. However, women have worse surgical outcome and a higher mortality following acute aortic dissection, which may represent inadequate diagnosis and treatment in women [3]. Women with bicuspid or mildly abnormal aortic valves demonstrate calcification later compared to males [5]. This is supported by the later mean age in women at the time of surgical intervention.

The risk of endocarditis has been observed to be less in women, perhaps due to better oral hygiene as well as lower rates of intravenous drug abuse [3, 10].

Indications for implantable cardioverter defibrillator (ICD) in patients with CHD were primarily derived from adult randomized trials and have evolved from secondary prevention of sudden cardiac death to treatment of sustained ventricular arrhythmias to primary prevention in patients with increased risk of sudden cardiac death [11]. Current recommendations for ICD placement in patients with CHD are for secondary prevention following sudden cardiac arrest or for symptomatic sustained ventricular tachycardia; for recurrent syncope of undetermined origin when either ventricular dysfunction is present or ventricular arrhythmias are inducible during electrophysiological study; or for recurrent syncope and significant systemic ventricular dysfunction [11]. Tracy et al. [12] report observational studies have shown systemic ventricular dysfunction in patients with CHD to be the most predictive risk factor for sudden cardiac death or appropriate ICD use, however, current guidelines have not been changed.

Women with ACHD are at a 55 % lower risk of implantation of an ICD compared to their male counterparts with only a slightly lower risk of developing arrhythmias [3]. There is a slight predominance of supraventricular arrhythmias in men, but no difference between genders in ventricular arrhythmias, which is a major indication for ICD placement in ACHD [3]. The ICD survival benefit demonstrates no significant gender difference which does not explain the significant gender difference between ICD placement [3, 10].

Only 34–51 % of women with ACHD recall discussing contraception or pregnancy issues regarding potential risks with their physicians [12, 13]. The importance of discussing and managing contraception is crucial when caring for women in general and particularly important in women with ACHD as pregnancy risks to both mother and child can be increased [13–15]. Most female patients with ACHD can and should be managed as normal with respect to contraceptive discussions and treatment. Exceptions are women with certain forms of complex congenital heart disease, significant aortic pathology, pulmonary hypertension, cyanotic congenital heart disease, valve replacements and congestive heart failure [5, 14]. These groups of female ACHD patients are at higher risk for development of side effects and complications with estrogen based contraceptives, and counseling must address both maternal risks as well as fetal [15].

Natural methods of contraception (withdrawal and safe period) as well as barrier methods (condom and diaphragm) have high failure rates and are not recommended [15]. Low-estrogen contraceptive pills, or combined contraceptive pills, come with significant side effects such as fluid retention, elevated blood pressure, additional risk of thromboembolic events in patients with an already increased risk, alteration in warfarin control which is particularly concerning in patients with prosthetic valves, and worsening pulmonary vascular disease [5, 15, 16]. Within the first 6 months of starting a low-estrogen contraceptive, approximately 15 % of cyanotic patients experience a thromboembolic event; if this risk is acceptable to both patient and provider, aspirin therapy should also be initiated [5]. Progesterone contraceptive pills do not carry the increased thromboembolism risk [15] although there may be a slight increased risk in polycythemic patients [5]. There are few serious side effects such as irregular menstrual bleeding, although women often experience a general unwell feeling [5, 15]. There is a high failure rate on the progesterone contraceptive pills in comparison to the combination contraceptive pills [15, 16].

Intrauterine devices (IUD) are highly effective in preventing pregnancy as in the general population, but come with a small risk of endocarditis at the time of insertion along with bleeding and sepsis [5, 15]. Mirena, a slow-release progestogen IUD, carries a slightly lower risk of endocarditis due to the suppression of endometrium, in addition to a very low pregnancy rate and a substantially reduced amount of menstrual bleeding [17]. Tubal ligation should be considered in women with ACHD who carry a significantly high risk of morbidity and mortality or when a woman with ACHD decides she does not want to have children [16–18].

Although heart disease in pregnancy accounts for only 1 % of all pregnancies, the majority of heart disease in pregnancy (70–80 %) is now due to ACHD [5] (Fig. 11.1)
.

Pregnancy in women with ACHD poses several potential problems in this generally higher-risk population. Pregnancy is a circulatory burden to women in general healthy states with subsequent increased cardiac output, heart rate and blood volume and decreased systemic vascular resistance, and in women with certain ACHD diagnoses, their ability to adapt to these physiological changes is compromised [14, 15, 19, 20]. While many ACHD diagnoses are associated with a normal pregnancy and normal outcomes, there is a higher incidence of miscarriages, premature deliveries, worsening heart failure and overall clinical deterioration [5, 14, 15, 18]. A systematic review by Drenthen et al. [14] reported 11 % of completed pregnancies in patients with ACHD experienced arrhythmias, heart failure and cardiovascular events that are generally rare in a healthy population.

Specific conditions that place women with ACHD at a higher risk include cyanotic lesions, presence of pulmonary hypertension, severe aortic stenosis, significant aortic pathology, congestive heart failure, and prosthetic, particularly mechanical, valves [5, 14, 17–19, 21]. Other conditions are less worrisome during pregnancy and include mild pulmonary valve stenosis, mild AS, bicuspid aortic valve without aortic stenosis, ASD without pulmonary hypertension, small VSD, mitral valve prolapse, TOF without sequelae, and small PDA [5, 18]. Obstetric complications do not appear to be more predominant in ACHD compared to the general population although infant mortality is higher, 4 % compared with <1 % in the general population and as high as 30 % in women with Eisenmenger physiology (Tables 11.2 and 11.3).