Pregnancy Outcomes in Adult Congenital Heart Disease Patients with Pulmonary Hypertension in Indonesia

Congenital heart disease (CHD), a group of structural abnormalities affecting the heart and major vessels, presents significant risks during pregnancy due to the substantial haemodynamic changes that occur. These include increased total blood volume, a 40–50% rise in cardiac output, elevated heart rate, reduced peripheral vascular resistance and a hypercoagulable state.¹ These physiological adaptations, while generally well-tolerated in healthy individuals, may worsen pre-existing cardiac defects, increasing the risk of right heart failure, pulmonary hypertension (PH) crisis and pulmonary embolism, culminating in elevated maternal morbidity and mortality.² Globally, 1–4% of pregnant women are affected by heart disease, with CHD comprising approximately 57% of cases.^3,4 Recent studies indicate a >30% rise in CHD prevalence during pregnancy, with current estimates suggesting a global rate of eight per 10,000 pregnancies.⁵ While maternal deaths from haemorrhage and infection have declined, CHD has emerged as the leading cause of mortality among pregnant women, particularly in cases complicated by pulmonary arterial hypertension (PAH), which carries a mortality rate of around 9%.

This review aims to explore the epidemiology and burden of adult CHD during pregnancy in Indonesia, highlighting both cardiovascular and obstetric outcomes as well as associated foetal implications.

Data Sources

A comprehensive literature review was conducted to identify studies published from inception to April 2025 using Ovid MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials. Eligible studies were required to report on maternal and foetal outcomes associated with adult CHD-related PH. Complex CHD is defined as severe CHD as classified in the CHD complexity by European Society of Cardiology guidelines on adult CHD.⁶ Maternal outcomes included the mode of delivery, incidence of complications, development of multiple organ dysfunction syndrome and maternal mortality in cases of CHD-related PAH. Foetal outcomes assessed included prematurity, birth weight, abortion, intrauterine foetal demise and neonatal mortality. A broad array of keywords related to pregnancy, adult CHD and PH was used during the search process.

This review also incorporated data from four PH centres in Indonesia: Dr Sardjito Hospital, Yogyakarta (data from 2018 to 2024), Hasan Sadikin General Hospital, Bandung (2019–2024), Saiful Anwar General Hospital, Malang (2022–2024) and M Djamil General Hospital, Padang (2017–2024). Each participating centre prospectively collected clinical and haemodynamic data from pregnant patients, both with and without CHD and PH, during the respective study periods. The CHD and PH registry at Dr Sardjito General Hospital, Yogyakarta – formally established in 2012 as the COngenital HeARt Disease in adult and Pulmonary Hypertension (COHARD-PH) registry – served as the primary published source.⁷ In contrast, datasets from the other centres have not been previously reported. All datasets, encompassing maternal, foetal, and obstetric outcomes from the four institutions, were harmonised and subsequently integrated for pooled analysis in the present review.

Definition and Diagnosis of PAH

PH represents a group of disorders characterised by elevated pressure in the pulmonary arteries. Clinically, PH is classified into five categories: PAH, PH associated with left heart disease, PH due to lung diseases, PH related to thromboembolic conditions and PH with multifactorial or unclear mechanisms.⁸ The current standard definition identifies PH by a resting mean pulmonary arterial pressure (mPAP) >20 mmHg, confirmed through right heart catheterisation. In the past, the diagnostic threshold was set at 25 mmHg; diagnosis also required a pulmonary vascular resistance (PVR) >2.0 Wood units.⁹ This revised threshold was introduced based on evidence showing increased risks of hospitalisation and mortality in individuals with mPAP values exceeding 20 mmHg. The change allows for earlier identification and treatment of PH. In the case of PAH, diagnosis requires meeting the general PH criteria along with two additional conditions: a PVR >2.0 Wood units and a pulmonary arterial wedge pressure ≤15 mmHg.^10–12 It is essential to rule out other causes, including cardiac, pulmonary or thromboembolic origins, before confirming a diagnosis of PAH. This diagnostic framework supports timely and accurate patient management.

Global Epidemiology of Maternal Congenital Heart Disease in Pregnancy

Cardiovascular diseases (CVDs) are observed in approximately 4–8% of pregnancies, with CHD representing the most prevalent form, comprising over half of all CVD cases in this population. Data from the EORP ROPAC registry documented 3,295 CHD cases among 5,739 pregnancies across 53 countries over a decade, of which 1,059 were uncorrected.¹³ Similarly, the CARPREG study reported that CHD accounted for 63.7% of all cardiovascular diagnoses in pregnant women.¹⁴

In the US, between 2010 and 2019, CVDs were diagnosed in 4,409,924 of 39,212,104 pregnancies. A notable upward trend was observed, with the prevalence increasing from 9.2% in 2010 to 14.8% in 2019. CHD was identified in 32,173 of these cases, stratified as simple (n=23,581), moderate (n=7,613) and complex (n=2,232), equating to prevalence rates of six, 1.9 and 0.6 per 10,000 pregnancies, respectively. PH was also reported in 21,042 women, with a prevalence of 5.4 per 10,000. Notably, both CHD and PH demonstrated increasing incidence, with CHD rising from 6.8 to 9.6 and PH from 4.8 to 6.9 per 100,000 pregnancies over the decade.¹⁵

Analysis of the Nationwide Inpatient Sample (2000–2010) in the US revealed that atrial septal defect (ASD) was the most frequent CHD type among pregnant women (22.6%), followed by ventricular septal defect (VSD; 14.5%), left-sided valvular lesions (13.8%) and right-sided valvular lesions (7.5%). Less common defects included coarctation of the aorta (2.9%), tetralogy of Fallot (TOF; 2.6%), transposition of the great arteries (1.5%), Ebstein’s anomaly (1.4%) and both total anomalous pulmonary return and truncus arteriosus (0.1% each). Pulmonary heart diseases were noted in 3.6% of these patients.¹⁶

A multicentre Chinese study (1993–2019) further highlighted CHD-associated PH, identifying 1,264 PH cases among 2,755 CHD pregnancies.¹⁷ Mild PH was reported in 398 cases, while 331 exhibited moderate to severe PH. Miscarriages or pregnancy termination occurred in 535 cases. Across all PH severity groups, ASD was the most prevalent lesion, followed by VSD, TOF and patent ductus arteriosus (PDA), accounting for 27.5%, 43.0% and 35.6% in populations without PH, with mild PH and with moderate to severe PH, respectively.

Data on Maternal Heart Disease and Adult CHD across Four Centres in Indonesia

As noted above, data from four Indonesian PH centres were also incorporated in this review. These previously unpublished data include 370 pregnant women with CHD collected between 2017 and 2024. Pregnancy in women with CHD contributed to 370 of 2,023 (18.3%) total adult female CHD cases across the four centres.

Among all pregnancies complicated by CHD, ASD was the most prevalent lesion, accounting for 46.8% (173 of 370 cases) across all centres. This was followed by VSD and PDA, which comprised 22.2% and 14.1% of cases, respectively. The complete distribution of CHD aetiologies among pregnant patients is presented in Figure 1.

Among the 370 pregnant women with CHD, 61.6% (228 patients) were diagnosed with intermediate-to-high probability of PH based on echocardiographic assessment. A total of 46.7% patients delivered via caesarean section. Notably, 313 patients (84.6%) had not undergone prior corrective surgery for their cardiac defect. There was no notable difference in clinical outcomes between nulliparous and multiparous women. Overall, 86.4% of the women successfully completed their pregnancies with delivery, while 8% experienced spontaneous or induced abortion.

Management of Adult CHD-associated PAH in Pregnancy

CHDs characterised by left-to-right shunting, such as PDA, ASD and VSD, are generally well tolerated during pregnancy, provided PH does not develop.¹⁸ However, the onset of PH in pregnancy is associated with a significantly increased risk of adverse maternal and foetal outcomes. Consequently, pregnancy termination is commonly recommended in such cases.¹⁹ Despite these well-documented risks, a subset of patients elects to continue with pregnancy. In these circumstances, particularly in the context of PH during gestation, a multidisciplinary management strategy is imperative.

For patients who choose to proceed with pregnancy, the principal therapeutic objective in managing PAH associated with adult CHD is the preservation and optimisation of right ventricular function.²⁰ Current pharmacological therapies for PAH are classified into four main categories: endothelin receptor antagonists, phosphodiesterase type 5 inhibitors (PDE5i), prostacyclin analogues and bone morphogenetic protein receptor/activin inhibitors.²¹ The administration of these agents during pregnancy is contingent upon their teratogenic potential and safety profiles. In China, PAH-specific treatments, including prostacyclin analogues, such as epoprostenol, and PDE5i agents, such as sildenafil, have been used over the past decade in pregnant women with PAH.²² In Indonesia, sildenafil remains the sole PAH-specific pharmacological agent available for use in pregnancy. Data from Dr Sardjito Hospital involving 32 pregnant women with adult CHD-associated PAH demonstrated that sildenafil therapy led to improved maternal and foetal outcomes, including reductions in maternal and foetal mortality, intrauterine growth restriction (IUGR), small for gestational age (SGA) and oligohydramnios.²³

In cases where PAH progresses to an irreversible state or culminates in Eisenmenger’s syndrome, the risk of maternal mortality rises dramatically, reaching approximately 30%, rendering pregnancy a formal contraindication. Additionally, the risk of adverse foetal outcomes, including IUGR, preterm birth and foetal demise, is markedly elevated. If pregnancy is continued despite these risks, delivery is exclusively indicated via caesarean section between 32 and 34 weeks of gestation. Postpartum, the risk of maternal mortality remains substantial; therefore, a minimum hospitalisation period of 2 weeks following delivery is recommended for close monitoring and management.¹⁸

Multidisciplinary Approach for Adult CHD-associated PAH in Pregnancy

A multidisciplinary team approach is essential for optimising the care and clinical outcomes of pregnant women with adult CHD. This model emphasises comprehensive risk assessment to guide timely decisions regarding the continuation or termination of pregnancy. The effectiveness of such an approach has been demonstrated by Chen et al., who reported a significant reduction in maternal mortality and cardiovascular complications, albeit with an associated increase in the rate of therapeutic abortions.²² For women with adult CHD and PAH who choose to proceed with pregnancy, it is strongly recommended that they undergo regular evaluations by a cardiologist, obstetrician and PH specialist – ideally on a biweekly basis during the second trimester and weekly during the third trimester.¹⁹ The timing and appropriateness of pregnancy termination should be discussed proactively between obstetricians and CHD specialists. A multidisciplinary case review is typically convened between 20 and 24 weeks of gestation, a critical window when foetal viability increases and the risk of maternal cardiovascular events becomes more pronounced.²⁴ In addition, coordinated care by obstetric and cardiac nursing staff is vital in implementing individualised care plans and ensuring consistent follow-up prior to delivery. Postpartum care should include on-going monitoring, with nursing staff maintaining regular contact during the first 2 months after discharge to evaluate the patient’s clinical status and ensure continuity of care.

Maternal Outcomes of CHD and PAH in Pregnancy

Maternal outcomes are contingent upon the severity of pulmonary PH and the subtype of CHD. Data from retrospective studies indicate that PAH associated with CHD represents the predominant aetiology among various subtypes of PAH in pregnant women.^25,26 Zhang et al. (2023) demonstrated that maternal outcomes, encompassing cardiovascular complications including arrhythmia, infective endocarditis, cardiac failure, cardiogenic death, PH crisis and intensive care unit admissions, were significantly more favourable in the mild PAH cohort compared with the moderate-to-severe PAH cohort.¹⁷ Maternal mortality rates were substantially reduced in the mild PAH group relative to the moderate-to-severe group.^17,27 Notably, the mortality rate was highest in patients with idiopathic PAH relative to other aetiologies of PAH.^25,28

A retrospective study using data from the COHARD-PH registry at Dr Sardjito Hospital, spanning 2012 to 17, identified 78 pregnant women with CHD. Analysis revealed a maternal mortality rate of 12.5% (six of 48 patients with PH). Deceased patients exhibited poorer WHO functional class status, Eisenmenger’s syndrome, reduced right ventricular systolic function and right heart failure, indicating these as significant risk factors for adverse maternal outcomes.²⁹

Among the 370 pregnant women diagnosed with CHD in the four Indonesian centres, 8.9% (34 patients) died during the study period. The leading cause of maternal death was PH crisis (10 of 34 cases), followed by respiratory failure (six cases) and haemorrhagic shock (five cases). Maternal cardiac complications were also notable, with 39 patients (10.5%) developing left or right heart failure. A total of 21 patients experienced a PH crisis, of whom 10 (47.6%) subsequently died. Among all patients, one individual experienced a thrombotic event and another had an aortic dissection; both cases resulted in maternal death. Detailed maternal outcomes are presented in Figure 2.

Foetal and Obstetric Complications of Congenital Heart Disease and PAH in Pregnancy

Foetal outcomes remain a significant concern, with a retrospective analysis from 2008 to 2018 demonstrating that preterm deliveries occurred in 58% of gestations at a mean gestational age of 34 weeks and 1 day, predominantly (76%) delivered via caesarean section. The stillbirth rate was 3% and the neonatal mortality rate was 1%.²⁵ Adverse neonatal outcomes, encompassing SGA, low birth weight, neonatal asphyxia, preterm birth and neonatal mortality, were significantly associated with the severity of PH, with the highest prevalence observed in patients with moderate-to-severe PH.²⁷ Maternal hypoxaemia, particularly in the context of Eisenmenger’s syndrome, is a robust predictor of adverse foetal prognosis, with cyanosis (oxygen saturation <85%) significantly diminishing live birth rates.^30,31

During the study period, 22,244 deliveries were documented in the four centres. A total of 1.44% deliveries were associated with pregnant women with adult CHD. Among the 320 recorded births, 45.9% (147 of 320) resulted in preterm delivery (<36 weeks of gestation). Foetal or neonatal death within the first week postpartum occurred in 21 pregnancies. Low birth weight (<2,500 g) was observed in 101 newborns (31.5%) and IUGR was diagnosed antenatally in 51 cases. Cardiac anomalies were identified in five neonates (1.5%), including two cases of ASD, two of VSD and one case presenting both a PDA and an ASD. Notably, all affected neonates were born to mothers with CHD-PAH.

Among the 370 pregnancies in women diagnosed with CHD, 31.8% were complicated by obstetric issues. Hypertensive disorders, including hypertension and preeclampsia, were observed in 28 of 120 obstetric cases (23.3%). Additionally, 30 patients experienced threatened preterm labour before 34 weeks of gestation. Antepartum and postpartum haemorrhage occurred in eight cases, with five progressing to hypovolaemic shock, all of which resulted in maternal death. Fifty-five women required emergency caesarean section because of pregnancy-related complications. Detailed foetal and obstetric outcomes are presented in Figure 3.

Screening Programme for Maternal Heart Disease in Indonesia

Cardiovascular conditions such as CHD and PH often remain undiagnosed during pregnancy due to nonspecific symptoms. A recent study in proposed a tiered screening algorithm – starting from red-flag symptoms, vital signs and clinical risk factors – to identify women who may require further testing, such as ECG, natriuretic peptides or echocardiography, even in low-resource settings.³²

In Indonesia, antenatal care (ANC) includes basic assessments such as history taking, vital signs, cardiac auscultation and occasionally oxygen saturation monitoring. However, there is no standardised approach for cardiovascular risk stratification or guidance for further screening, and tools such as ECG or transthoracic echocardiography are not routinely used. Moreover, limited diagnostic facilities in rural areas hinder healthcare professionals in screening for CVDs early. These limitations contributed to the inadequate screening strategy in Indonesia, especially rural areas. Several initiatives have explored feasible screening approaches. Studies by Dinarti et al. integrated ECG and pulse oximetry into ANC and school-based programmes in Yogyakarta City, detecting heart abnormalities in 2.8% of 523 pregnant women and identifying 18 CHD cases among over 6,000 schoolchildren.^33,34

With Indonesia’s on-going health system reform through primary care transformation, there is an opportunity to incorporate cardiovascular risk assessment and screening into routine national antenatal care. This integration can be facilitated by the increasing availability of digital innovations – such as portable ECG devices, mobile applications and teleconsultation platforms – supported by interprofessional collaboration and integrated patient-centred care.^35–37

Conclusion

Adult CHD complicated by PH remains the most prevalent form of CVD affecting pregnant women, contributing significantly to maternal morbidity and mortality. Epidemiological data consistently identify ASD as the most common subtype of CHD globally. Among affected individuals, maternal death and heart failure are the principal adverse outcomes. Furthermore, this high-risk population faces an increased incidence of obstetric complications, including low birth weight, preterm delivery and a higher likelihood of caesarean section. Early diagnosis and the implementation of a comprehensive multidisciplinary care strategy are fundamental to optimising maternal and foetal outcomes in this vulnerable group.