Integrated management and prognosis analysis of 30 cases of fetal pulmonary valve abnormalities during pregnancy and perinatal period: a retrospective study

Introduction

Fetal pulmonary valve anomaly (PVA) mainly includes pulmonary atresia with intact ventricular septum (PA/IVS) and pulmonary stenosis (PS), which are rare types of congenital heart defects (CHD). The incidence of PS in live births is 6–8/10,000, accounting for 8–10% of children with CHD (1). The incidence of PA/IVS in live births is about 1/22,000, accounting for 1–5% of CHD. Such patients are usually accompanied by right heart dysplasia (2). Children with PVA, having little or no blood flowing into the pulmonary valve orifice for oxygenation, typically suffer from severe hypoxia and cyanosis with a critical condition. It is necessary to reconstruct the right ventricle-pulmonary artery circulation as soon as possible. This type of CHD is often associated with varying degrees of right heart system dysplasia. The prognosis of children also varies according to the severity of their condition and the surgical procedures they need to choose (3). With the development of prenatal ultrasound diagnosis and improvements in pediatric cardiac surgery technology, fetal PVA can be detected in the second trimester, providing conditions for early intervention and treatment after birth. Nevertheless, there are currently few reports on prenatal consultation, integrated management during the perinatal period, and prognosis evaluation of fetal pulmonary valve abnormalities especially in China. Our study retrospectively summarizes the perinatal consultation, integrated management during the perinatal period, neonatal management, and prognosis of fetal PVA at Peking University People’s Hospital, aiming to provide experience for prenatal consultation, integrated management during the perinatal period, and prognosis evaluation. We present this article in accordance with the STROBE reporting checklist (available at https://tp.amegroups.com/article/view/10.21037/tp-24-165/rc).

Methods

Source of data

Between January 2019 and March 2023, we identified 30 pregnant women with fetal PVA through prenatal ultrasound at Peking University People’s Hospital. Among them, 24 cases were transferred to our hospital (Peking University People’s Hospital) from other medical facilities, including 16 cases from hospitals in Beijing and 8 cases from Tianjin, Hebei, Shandong, Henan, Anhui, and Inner Mongolia provinces.

Study methods

Ultrasound examination

Ultrasound examinations of the 30 PVA fetuses were conducted and validated by qualified ultrasound physicians at our hospital using the Voluson E8 Expert machine (GE Healthcare, Kretztechnik, Zipf, Austria). Prenatal systematic ultrasound screening involved routine measurements of fetal parameters such as biparietal diameter, head circumference, femur length, abdominal circumference, placenta, amniotic fluid volume, etc. Additionally, we assessed umbilical artery blood flow and examined fetal heart, brain, face, abdominal cavity, spine, four limbs, and urinary system for abnormalities.

Diagnosis of fetal PVA

Following the Guidelines for Ultrasound Examination of Fetal Heart in China by the Ultrasound Doctor Branch of the Chinese Medical Doctor Association (4), we adhered to the standardized examination process and standard section of fetal heart. We obtained views, including four-chamber view (4CV), left ventricular outflow tract view (LVOV), right ventricular outflow tract view (RVOV), three-vessel view (3VV), major artery short-axis view, biventricular short-axis view, long-axis view, etc. We also measured pulmonary artery bifurcation with branches, pulmonary veins, atrial septum and foramen ovale, atrioventricular inflows, ductal arch, aortic arch, heart rate and rhythm, aortic and pulmonary valve annulus in systole, tricuspid and mitral valve annulus in diastole, ductus arteriosus and aortic isthmus diameters and so on with color Doppler. We followed the segmental diagnosis principle of CHD to sequentially assess the relationship between visceral and atrial position, atrial venous connection, atrial ventricular connection, and ventricular and great artery connection. Ultrasound diagnosis was then performed based on the criteria for PS and pulmonary valve atresia. PS with concomitant right ventricular dysplasia was categorized as severe PS, while PS without associated right ventricular dysplasia was considered mild PS (4,5).

Prenatal screening and diagnosis process

Ultrasound examinations were conducted on pregnant women at 11 to 13⁺⁶ weeks of pregnancy to determine the thickness of nuchal translucency (NT). NT ≥0.25 cm was diagnosed as NT thickening. Before the identification of PVA by ultrasound examination, prenatal screening could opt for second-trimester prenatal screening or non-invasive prenatal testing (NIPT) for fetal chromosome aneuploidy screening. Pregnant women with indications for amniocentesis (advanced age or abnormal ultrasound soft markers, including fetal PVA found by ultrasound) were consulted by doctors with prenatal diagnosis qualifications. Upon obtaining informed consent from pregnant women and their families, amniocentesis or umbilical venipuncture was performed. G banding chromosome karyotype analysis (CKA) and single-nucleotide polymorphism microarray (SNP array) examinations of the fetuses were conducted. Fetal tissue from induced abortion patients was utilized for fetal CKA and SNP array examinations. Amniocentesis was recommended for all PVA fetuses found by ultrasound, with informed consent obtained from pregnant women who resolutely refused amniocentesis.

Integrated management during perinatal period

For pregnant women with identified fetal PVA during pregnancy, multidisciplinary treatment (MDT) was implemented, involving collaboration between the obstetric ultrasound department, cardiac surgery department, neonatal department, pediatric cardiac surgery, and prenatal diagnosis center. The risk of fetal PVA was graded based on the imaging situation (6). Pregnant women and their families were thoroughly informed about the potential risks of PVA during the perinatal period, and corresponding treatment methods were provided. Cervical canal length was measured every 2–4 weeks for pregnant women without symptoms of threatened premature birth to prevent premature birth and monitor fetal growth restriction (FGR). A personalized plan was formulated based on the individual conditions of each pregnant woman. Neonatal pediatricians were present at the time of delivery, with collaboration between obstetrics and pediatrics to manage the newborn, and timely transfer to pediatric cardiac surgery for necessary interventions.

Follow-up

The prognosis of the newborns was monitored through telephone follow-ups and outpatient visits, in conjunction with pediatric cardiac surgery at Fuwai Hospital, Chinese Academy of Medical Sciences. Follow up period was 1–2.5 years.

The study was conducted in accordance with the Declaration of Helsinki (as revised in 2013). The study was approved by the Ethics Committee of Peking University People’s Hospital (No. 2023PHB291-001) and informed consent was obtained from pregnant women.

Statistical methods

We utilized SPSS 22.0 (IBM, Armonk, NY, USA) for data analysis. The measurement data of normal distribution were presented as mean ± standard deviation, while counting data were expressed as numbers and proportions.

Results

During the study period, ultrasound examinations identified a total of 30 fetuses with PVA. The gestational age of PVA diagnosed by ultrasound examination was 23.5±2.8 weeks. The pregnant women had an average age of 33.1±3.6 years, a gravidity of 2.0±1.2, and a parity of 0.5±0.7. None of the pregnant women had a history of adverse pregnancy or childbirth. In the 30 pregnant women, 5 had thyroid dysfunction, 5 had gestational diabetes, 4 had preeclampsia, and 1 had cardiac insufficiency.

Prenatal screening, prenatal diagnosis, and prognosis of PA/IVS

Among the 30 cases of fetal PVA, 6 cases (20.0%) were diagnosed with PA/IVS. Figure 1 illustrates the specific pregnancy and perinatal conditions.

Figure 1 Prenatal screening, prenatal diagnosis and prognosis of PA/IVS. PA/IVS, pulmonary atresia with intact ventricular septum; NT, nuchal translucency; NIPT, non-invasive prenatal testing; ASD, atrial septal defect; CKA, chromosome karyotype analysis; SNP, singlenucleotide polymorphism; CS, cesarean section; TBV, transthoracic balloon (pulmonary) valvuloplasty; BT, Blalock-Taussig shunt; LDA, ligation of ductus arteriosus.

All cases of fetal PA/IVS had normal NT. One case (1/6) showed a high risk during the second-trimester prenatal screening, but subsequent NIPT indicated low risk. The remaining 5 cases (5/6) had a low risk according to NIPT.

Among the 6 PA/IVS fetuses, 1 case (1/6) opted not to undergo amniocentesis and also refused to have umbilical cord blood collected for CKA or SNP array after delivery, while the other 5 cases (5/6) had normal amniocentesis results (CKA and SNP array).

Two cases (2/6) terminated the pregnancy due to intracardiac abnormalities found by ultrasound. One case presented with atrial septal defect (ASD), while the other case had dextrocardia. One case (1/4) of the 4 live births showed a small amount of pleural effusion detected by ultrasound (Table 1).

All 4 delivery patients (4/6) underwent cesarean section (CS) based on obstetric indications. The gestational age at delivery was 37.0–39.2 weeks, and the birth weight was 3,000–3,560 g, with a male-to-female ratio of 3:1. Post-birth, all patients received alprostadil at a rate of 6.00–13.00 ng/min/kg. Within 3 to 7 days after birth, they underwent transthoracic balloon (pulmonary) valvuloplasty (TBV) + modified Blalock-Taussig shunt (BT) + ligation of the ductus arteriosus. All 4 patients were followed up for 16–24 months and exhibited satisfactory recovery. Ultrasound revealed alleviated PS, significant pulmonary valve regurgitation, and moderate tricuspid valve regurgitation. The specific details of newborns during delivery are outlined in Table 2.

Prenatal screening, prenatal diagnosis, and prognosis of PS

Among the 30 fetal PVA patients, 24 (80%) had PS. Figure 2 illustrates the specific pregnancy and perinatal conditions. Among the 24 pregnant women with fetal PS, 5 were twins (5/24), of which 4 were dichorionic diamniotic twins, all conceived through in vitro fertilization-embryo transfer (IVF-ET). The other case was monochorionic diamniotic twins, resulting from natural pregnancy, with one of the twins diagnosed with fetal PS.

Figure 2 Prenatal screening, prenatal diagnosis and prognosis of PS. PS, pulmonary valve stenosis; MCDA, monochorionic diamniotic; DCDA, dichorionic diamniotic; IVF-ET, in vitro fertilization-embryo transfer; NT, nuchal translucency; NIPT, non-invasive prenatal testing; VSD, ventricular septal defect; CKA, chromosome karyotype analysis; SNP, single-nucleotide polymorphism; CS, cesarean section.

One of the 24 fetal PS patients exhibited NT thickening (1/24), leading to further prenatal testing. Eight (8/24) patients underwent mid-term prenatal screening, with 7 (7/8) at low risk and 1 (1/8) at critical risk. The woman at critical risk opted for NIPT, which revealed a low-risk result. Twelve patients (12/24) chose NIPT due to advanced age and other factors, and all were at low risk. Four patients (4/24) underwent amniocentesis due to advanced age and other factors, leading to direct amniocentesis.

Seven out of twenty-four (7/24) patients elected to terminate their pregnancies and underwent amniocentesis, revealing normal karyotypes. Among these, 1 patient (1/7) exhibited an abnormal SNP array result, identifying the pathogenic gene responsible for Beckwith Wiedemann syndrome. Out of the 17 (17/24) delivered patients, 6 (6/17) with normal NIPT opted against further amniocentesis. Meanwhile, 11 (11/17) patients who underwent amniocentesis had normal karyotypes. Within this group, 5 (5/11) displayed normal SNP array results, 4 (4/11) refused SNP array examination, and 2 (2/11) exhibited abnormal SNP array results, namely a 2.9 MB deletion of Yp11.2 and the deletion of a 482.1 Kb fragment in 2q13, both identified as nonpathogenic.

Ultrasound diagnosis revealed 4 cases of severe fetal PS (4/24) and 20 cases of mild stenosis (20/24) among the twenty-four patients. Additionally, 5 cases (5/24) exhibited extracardiac abnormalities, including widened lateral ventricles, hypoxic-ischemic encephalopathy, short femur, intracranial hemorrhage, and thick forehead skin. One case (1/24) presented intracardiac abnormalities diagnosed as ventricular septal defect (VSD). No other ultrasound abnormalities were found in the remaining patients.

Out of the seventeen delivery patients, 7 (7/17) were delivered transvaginally, 1 (1/17) via forceps, and 9 (9/17) through CS. All indications for delivery were obstetric, with an average gestational age of (37.8±1.0) weeks and an average birth weight of 3,288.8±404.6 g, resulting in a male-to-female ratio of 12:5. Among the seventeen neonates, 3 (3/17) with severe PS underwent TBV, modified BT, and Ductus arteriosus ligation on the 7^th day after birth. These neonates were followed up for 6 to 24 months, all recovering well with relief of PS. In the group of 14 mild PS patients (14/17), 1 case (1/14) succumbed within 1 week of birth, attributed to chronic hypoxia in the uterus leading to hypoxic-ischemic encephalopathy. Two cases (2/14) received surgical treatment, with one undergoing TBV 5 days after birth, and the other undergoing TBV, modified BT, and ligation of the ductus arteriosus 6 days after birth. All patients were followed up for 12–30 months, with ultrasound results indicating normal pulmonary valve blood flow.

Seven cases (7/14) among the mild PS patients were detected by echocardiography after birth, the results consistent with prenatal findings, and did not require surgical treatment. Four cases (4/14) did not show PS during postnatal echocardiography, yielding a positive predictive value of 71.4% for prenatal ultrasound diagnosis of mild PS. Table 2 provides detailed information on the specific circumstances of newborns during delivery.

Discussion

Prenatal ultrasound diagnosis of fetal PVA

PA with or without IVS, or severe PS represents rare CHD with a notable natural fatality rate. Without intervention, approximately 50% of newborns succumb within 2 weeks post-birth, escalating to 85% within 6 months. Swift and active intervention is imperative upon the diagnosis of PA/IVS or severe PS in newborns to reconstruct right ventricle-pulmonary artery circulation, enhance blood oxygen saturation, and improve overall quality of life. Tailored treatment approaches for varying degrees of right heart system dysplasia have been elucidated in prior investigations (7).

Advancements in ultrasound technology have facilitated the prenatal detection of fetal PVA, offering a critical window for subsequent prenatal diagnosis, prompt resuscitation, transportation, and postnatal surgical interventions. This comprehensive approach significantly diminishes the risk of neonatal mortality. Presently, PVA diagnosis remains challenging via ultrasound, albeit the clarity in diagnosing PA/IVS and severe PS. A meta-analysis by van Velzen et al. underscores a 58.5% prenatal ultrasound diagnosis rate for PVA (8). This study corroborates postnatal outcomes with the prenatal diagnosis of PA/IVS and severe PS, yielding a positive predictive value of 71.4% for mild PS. The superior diagnostic accuracy is attributed to the utilization of the 4CV, LOTV, ROTV, and 3VV in our hospital’s ultrasound diagnosis protocol.

Two fetuses with mild PS needed surgical interventions shortly after birth, indicating that their PS may not mild. Therefore, neonates with PS needed to undergo a follow-up neonatal echocardiogram after birth to further evaluate the condition of the pulmonary valve.

Notably, fetuses with isolated PVA exhibit improved prognoses with postnatal surgical interventions. For PVA cases associated with intracardiac and extracardiac abnormalities, personalized treatment plans are recommended based on the specific nature of these abnormalities. Neonates with extracardiac abnormalities that do not compromise subsequent survival may undergo appropriate treatment post-delivery with informed consent. However, this study highlights a case of a neonate diagnosed with hypoxic-ischemic encephalopathy during pregnancy, emphasizing the importance of comprehensive communication with the family to make informed decisions regarding fetal prognosis, pregnancy continuation, and newborn treatment.

Prenatal diagnosis of fetal PVA

Existing literature posits that 20% to 33% of fetuses with CHD harbor chromosomal or genetic abnormalities (9). Consequently, it is strongly advised to conduct amniocentesis with full informed consent from pregnant women and their families, particularly for PVA fetuses with multiple abnormalities. In our study, among the PS cases, 14 underwent simultaneous SNP examination, revealing 3 cases with abnormal SNP results. These cases included 1 pathogenic abnormality and 2 nonpathogenic abnormalities. Although karyotype analysis of fetal chromosomes in this study yielded normal results, the inclusion of SNP array analysis revealed abnormalities in 1 out of 19 cases, surpassing the risk in the general population. Hence, it is recommended, with comprehensive informed consent, to conduct prenatal diagnosis for fetuses and advocate for the joint inspection method of karyotype analysis and SNP array for an in-depth genetic assessment.

Management of pregnant women with fetal PVA during pregnancy and the perinatal period

Currently, literature highlights the importance of a collaborative assessment involving the ultrasonic department, obstetrics, and pediatric cardiac surgery department for pregnant women with fetal CHD such as fetal PVA. This joint evaluation during pregnancy aims to determine the appropriate level of care (LOC), with distinct perinatal treatments based on the identified level (10). In our study, pregnant women diagnosed with fetal PVA underwent a multidisciplinary consultation.

Physicians specializing in obstetrical ultrasound and echocardiography conducted imaging analysis and dynamically monitored fetal heart conditions. Cardiac surgery and pediatric cardiac surgery specialists assessed the risk level of fetal PVA based on imaging conditions. They analyzed potential issues that the newborns might face post-birth, formulated a precise treatment strategy, and determined the optimal timing for intervention. Obstetricians consistently measured cervical length during pregnancy, monitored fetal conditions, and proactively identified and addressed premature birth and FGR to enhance newborn prognosis. Also we assessed the fetal heart condition and did not require prenatal treatment, so we did not take the risk of intrauterine treatment during pregnancy, which reduced the risk of maternal complications. Moreover, the prognosis of newborns was good, so it is worth further exploring whether it is necessary for most PVA fetus to undergo prenatal treatment.

Giorgione et al. found major CHD are significantly associated with the risk of maternal complications, such as preeclampsia and preterm birth (11), which can also lead to adverse outcomes for CHD newborns. So adequate prenatal and intrapartum management should be recommended in pregnant women with CHD fetuses on top of adequate neonatal assistance.

Our approach involved developing a personalized perinatal plan, integrating the expertise of obstetricians and neonatal doctors during delivery. Our experience underscores the importance of selecting the delivery mode based on obstetric factors, with fetal PVA not mandating a CS. However, deliveries should be scheduled on workdays with ample manpower and convenient referral options to avert emergency situations. If no other obstetric factors are present, cervical examination is recommended after 38 weeks. If the cervix is mature, admission to the hospital for induced labor commences, while induction is performed at 40 weeks if the cervix is not mature. CSs are reserved for cases necessitating it due to obstetric factors, scheduled on workdays, instead of fetal PVA. Regardless of the delivery mode, coordination with neonatal pediatricians is imperative for advance planning, neonatal transfer vehicle preparation, and swift transfer to a department equipped for cardiac surgery and monitoring immediately after birth. This integrated management involves collaboration across obstetrics, pediatrics, and pediatric cardiac surgery.

While prenatal ultrasound facilitates the diagnosis of fetal PVA, post-birth evaluation by doctors and monitoring of blood oxygen saturation remain crucial. All PVA newborns undergo blood oxygen saturation monitoring after birth, and preparation of medication and infusion equipment, such as alprostadil, is done in advance. Coordination with relevant referral departments ensures timely bed reservations for newborns. PVA neonates with low blood oxygen saturation require medications to maintain an open Ductus arteriosus and readiness for subsequent surgery (9). Our findings indicate a higher likelihood of alprostadil usage for PA/IVS and severe PS newborns. Mild PS patients with normal blood oxygen saturation after birth typically only require normobaric oxygen inhalation for optimal saturation.

Prognosis of PVA in newborns

The literature indicates that PVA remains a region associated with high lethality, with an overall survival rate of 80% in this series. Consequently, consideration for early transmission referral is advisable for these patients (12). Comprehensive echocardiography should be performed on different types of PVA fetuses after birth, and the choice of surgical method should be based on the specific type of PVA, with the potential for achieving a favorable prognosis through surgery (13).

In this study, four children with PA/IVS underwent TBV, modified BT shunt, and ductus arteriosus ligation within 1 week after birth. Postoperative reexamination yielded positive results, although the possibility of secondary surgery remained. Surgical treatment was administered to three patients with severe PS within 1 week after birth, resulting in good follow-up examinations without the need for a second surgery. Among the 13 patients with mild PS, only two underwent surgical treatment after birth, exhibiting a good prognosis with no necessity for secondary surgery. Consequently, PVA newborns, especially those without additional complications after birth, can achieve a positive prognosis following surgical treatment. However, personalized consultation and full informed consent are crucial for pregnant women with varying economic levels and family situations. The most beneficial approach for pregnant women and newborns should be selected judiciously, and efforts to explore suitable options should persist.

This study represents a medium- to short-term follow-up of newborns, emphasizing the need for further long-term observation to fully comprehend the prognosis of newborns.

Conclusions

The use of CKA and a SNP array test is recommended for the prenatal diagnosis of PVA fetuses detected by ultrasound during pregnancy. This should be conducted with the full informed consent of pregnant women and their families, facilitating individualized assessments and treatment plans based on fetal PVA and associated abnormalities. The mode of delivery can be chosen according to the obstetric situation. Following birth, neonatologists should be present for resuscitation and treatment. If necessary, alprostadil should be administered to maintain the openness of the ductus arteriosus, and timely transfer to pediatric cardiac surgery for surgery should be arranged. A positive prognosis can be achieved through surgery if the newborn does not experience any other complications after birth.

Acknowledgments

We would like to thank all the hospital staff of Peking University People’s Hospital and Fuwai Hospital for their support of our work.

Funding: None.

Footnote

Reporting Checklist: The authors have completed the STROBE reporting checklist. Available at https://tp.amegroups.com/article/view/10.21037/tp-24-165/rc

Data Sharing Statement: Available at https://tp.amegroups.com/article/view/10.21037/tp-24-165/dss

Peer Review File: Available at https://tp.amegroups.com/article/view/10.21037/tp-24-165/prf

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://tp.amegroups.com/article/view/10.21037/tp-24-165/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The study was conducted in accordance with the Declaration of Helsinki (as revised in 2013). The study was approved by the Ethics Committee of Peking University People’s Hospital (No. 2023PHB291-001) and informed consent was obtained from pregnant women.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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