Absent pulmonary valve syndrome is among the rarest of congenital cardiac anomalies. It is defined by the absence, or severe underdevelopment, of the pulmonary valve, the one-way gate that normally prevents blood from flowing backward from the pulmonary artery into the right ventricle. Without that valve, every heartbeat drives blood forward through a narrowed outflow tract and then lets it slosh backward in diastole, hammering the pulmonary arteries from both directions. The result is the condition’s signature finding: massive, sometimes aneurysmal dilation of the pulmonary arteries and their branches, which in the confined space of the fetal thorax can compress the airways and crowd out the surrounding structures. Precise incidence figures are difficult to pin down, but recent reviews suggest that absent pulmonary valve syndrome accounts for roughly 0.2 to 0.4 percent of all congenital heart disease, and that among fetuses diagnosed prenatally, more than 84 percent occur in association with tetralogy of Fallot, the classic conotruncal defect combining a ventricular septal defect, an overriding aorta, right ventricular outflow obstruction, and right ventricular hypertrophy.

The prognosis for fetuses diagnosed with this physiology before birth is sobering. In one series of 37 prenatally diagnosed fetuses, survival after initial diagnosis was only about 37 percent overall, with survival of roughly 30 percent for the tetralogy-associated variant. Against that backdrop, the new case report adds an unusual twist: the fetal heart was not only burdened by a suspected absent pulmonary valve but was also positioned abnormally, with dextrocardia, a rightward orientation of the cardiac apex within a normally positioned abdominal situs. Isolated dextrocardia of this kind is itself rare and is reported to be accompanied by complex intracardiac defects in the vast majority of cases, carrying a worse outlook than the mirror-image variety. The combination of a conotruncal malformation, absent pulmonary valve physiology, and dextrocardia in a single fetus is exceptionally uncommon, and the authors present it as a contribution to the limited literature on the prenatal natural history of this cluster of anomalies.

The mother was a 33-year-old woman in her second pregnancy, referred at 24 weeks of gestation for fetal cardiac evaluation. She carried a diagnosis of pre-gestational diabetes mellitus with demonstrably suboptimal glycemic control; her hemoglobin A1c at admission was 8.3 percent, well above the thresholds associated with elevated risk of fetal malformation. No additional maternal risk factors were identified. The referral triggered a comprehensive fetal echocardiographic workup using two-dimensional imaging, M-mode, color Doppler, and spectral Doppler, the full modern toolkit of prenatal cardiac diagnosis, and it is the meticulous serial documentation that gives this report much of its scientific value.

The initial scan at 24 weeks established the anatomy in detail. The fetal heart sat with a rightward apex, consistent with isolated dextrocardia. The main pulmonary artery was already markedly dilated, measuring 15 millimeters, and Doppler interrogation demonstrated both pulmonary stenosis and significant pulmonary regurgitation, with diastolic retrograde flow visible in the main pulmonary artery. The right ventricular free wall appeared hypertrophied, and imaging of the left ventricular outflow tract revealed a large subaortic ventricular septal defect with an overriding aorta, findings squarely compatible with a conotruncal anomaly on the tetralogy spectrum. Imaging of the pulmonary valve region showed only rudimentary ridges where normal leaflets should have been, the echocardiographic hallmark of the absent pulmonary valve variant. At that stage the fetus showed no signs of hydrops, and umbilical Doppler indices remained normal, suggesting that despite the severity of the anatomy, the circulation was still compensating.

What followed over the next four weeks was a documented unraveling of that compensation. Serial scans tracked the main pulmonary artery as it ballooned from 15 millimeters at 24 weeks to 18 millimeters at 26 weeks and 21 millimeters at 28 weeks. The cardiothoracic ratio, a measure of heart size relative to the chest, climbed from roughly 70 to 75 percent to as high as 80 percent, reflecting progressive biventricular hypertrophy and massive cardiomegaly. Doppler velocities across the stenotic, regurgitant pulmonary outflow rose in parallel. Then, at 27 weeks, the fetal echocardiogram revealed the development of hydrops fetalis, the accumulation of fluid in body cavities that signals decompensated cardiac failure. Bilateral pleural effusions appeared, followed by marked ascites. In structural fetal heart disease, the onset of hydrops is one of the most powerful adverse prognostic markers known, reflecting elevated central venous pressures and ventricular dysfunction, and reported series consistently show sharply increased fetal and neonatal loss once it supervenes.

Management options, the authors explain, were limited from the start. Given the complexity of the defects and the rapidly evolving hydrops, no intrauterine cardiac intervention was deemed feasible. The team instead pursued close surveillance with repeat echocardiography and intensive counseling of the parents about prognosis and potential perinatal outcomes. Despite maximal expectant management, the pregnancy ended at 30 weeks with intrauterine fetal demise secondary to progressive hydrops. Notably, by that point the mother’s HbA1c had improved to 6.6 percent, but the critical period of embryonic cardiac development had long since passed. Genetic assessment was incomplete: amniocentesis was not technically feasible because of the patient’s delayed presentation, although noninvasive prenatal testing had shown no evidence of trisomy 13, 18, or 21. The authors acknowledge that the absence of postmortem examination means the precise intracardiac anatomy, particularly the suspected absent pulmonary valve variant, could not be definitively confirmed, and that 22q11.2 deletion and other genetic contributors remain unassessed.

The mechanistic link to maternal diabetes is one of the most scientifically interesting dimensions of the case. Pre-gestational diabetes is a well-established, non-inherited risk factor for congenital heart disease, with particularly strong associations for conotruncal defects, exactly the spectrum observed here. The leading explanation involves hyperglycemia-driven oxidative stress during cardiac morphogenesis, the window in early pregnancy when the heart takes shape. Experimental models and human observational studies have repeatedly shown that elevated glucose impairs the survival and migration of cardiac neural crest cells, a transient embryonic cell population essential for septating the outflow tract and remodeling the aorticopulmonary structures, and disrupts endocardial cushion development. Population data reinforce the dose-response relationship: compared with normal HbA1c, values above 8 percent confer roughly a fourfold higher risk of major congenital heart disease, and even modest elevations above about 5.6 percent increase risk. Across large cohorts, pre-gestational diabetes raises the risk of all congenital heart defect subtypes, with the greatest excess for outflow-tract defects. Emerging work also suggests genetic modifiers, including reduced NOTCH1 function, that may render some fetuses more vulnerable to maternal hyperglycemia, hinting at a gene-environment interaction that could one day refine risk stratification.

For clinicians, the case is a pointed argument for targeted early fetal echocardiography, typically performed between 18 and 22 weeks and earlier when feasible, in pregnancies at elevated risk, including all those complicated by pre-gestational diabetes. Early diagnosis enables comprehensive anatomic and rhythm assessment, serial surveillance for evolving ventricular hypertrophy, outflow obstruction, and heart failure, genetic counseling and testing for conditions such as 22q11.2 deletion, and multidisciplinary delivery planning at tertiary centers. It also opens the door to realistic counseling: in published cohorts of fetal dextrocardia, most cases involve complex heart disease, and outcomes range widely depending on associated defects. But the deepest lesson of this report lies upstream of any scanner. Once hydrops appears in structural fetal heart disease, therapeutic options in utero are few, and outcomes deteriorate dramatically. The single most effective intervention to prevent cases like this one happens before conception, through tight glycemic control and maternal education. This fetus’s heart, imaged in such painful detail as it failed, stands as a vivid scientific case study and, equally, as a public health message: the fourfold elevated risk carried by an HbA1c above 8 percent is modifiable, and the time to modify it is months before a positive pregnancy test, not at 24 weeks when the heart has already formed and the damage is done.

Subject of Research: Prenatal diagnosis of suspected tetralogy of Fallot with absent pulmonary valve syndrome and dextrocardia in a pregnancy complicated by pre-gestational diabetes mellitus

Article Title: Coexistence of Suspected Tetralogy of Fallot With Absent Pulmonary Valve and Dextrocardia in Pre‐Gestational Diabetes Mellitus: A Case Report

Article References: Golbabaei, A., Kahani, V., & Mousivand, M. (2026). Coexistence of Suspected Tetralogy of Fallot With Absent Pulmonary Valve and Dextrocardia in Pre‐Gestational Diabetes Mellitus: A Case Report. Clinical Case Reports, 14(10), Article e73597. https://doi.org/10.1002/ccr3.73597

Image Credits: AI Generated

DOI: 10.1002/ccr3.73597

Keywords: tetralogy of Fallot, absent pulmonary valve syndrome, dextrocardia, pre-gestational diabetes, fetal echocardiography, congenital heart disease, hydrops fetalis, conotruncal defect, HbA1c, neural crest cells, intrauterine fetal demise, prenatal diagnosis

The research, led by A.R. Thomas and L.N. Trulsen alongside senior author P.T. Levy and colleagues, applied video-based assessment to delivery room stabilization of newborns with prenatally diagnosed congenital heart disease. The approach borrows from a methodology that has gained traction in adult resuscitation and trauma care over the past two decades but has been applied far more sparingly in neonatology. Rather than relying on the retrospective, often incomplete documentation that clinicians enter into electronic health records after the fact, the investigators analyzed synchronized audiovisual recordings of actual stabilization events, capturing what was done, when it was done, in what sequence, and how the team communicated throughout. The contrast between what the videos show and what the charts record forms the conceptual heart of the paper, reflected in its subtitle: “Insights beyond chart review.”

The clinical stakes of delivery room management for infants with congenital heart disease are considerable. Unlike the general neonatal population, these babies frequently require a highly individualized approach to the first minutes of life. Some lesions, such as hypoplastic left heart syndrome or critical aortic stenosis, depend on ductal patency to maintain systemic blood flow, making timely prostaglandin initiation essential. Others, including transposition of the great arteries with restrictive atrial communication, may require urgent balloon atrial septostomy within hours. Many benefit from careful titration of oxygen, because hyperoxia can precipitously drop pulmonary vascular resistance in ways that steal systemic output, while hypoxia risks failed transition. Standard neonatal resuscitation algorithms, designed primarily for term infants without known cardiac lesions, must therefore be adapted, and the degree to which teams actually adapt them in real time has been almost impossible to measure with conventional methods.

Chart review, the standard instrument of quality improvement in neonatology, suffers from well-documented limitations. Documentation is typically written minutes to hours after the event, by multiple team members, and is heavily shaped by what is required for billing and medico-legal protection. Time intervals are frequently rounded or estimated. Deviations from protocol, hesitations, communication breakdowns, and near-misses rarely appear in the record unless they result in obvious harm. Clinical trials of resuscitation interventions have repeatedly shown that chart-derived timing data diverge substantially from objective measurements. The Journal of Perinatology study leverages this known gap as its central analytical opportunity, asking specifically whether the stabilization of cardiac neonates, a population in whom precise sequencing and dosing matter enormously, is documented accurately enough to support quality improvement, and what additional knowledge video review can extract.

Video-based assessment in neonatal care has precedent. The Neonatal Resuscitation Program and various international registries have supported recording of resuscitations, and studies from centers in the United States, Europe, and Australia have used video to examine delay to ventilation, bag-mask technique, heart rate assessment, and thermal management. However, most of this work has focused on general resuscitation or extremely preterm infants. Applying the method specifically to newborns with prenatal cardiac diagnoses represents a meaningful extension, because it allows researchers to evaluate whether the elaborate pre-delivery planning that characterizes fetal cardiac programs translates into delivery room execution. The multidisciplinary nature of these deliveries, often involving neonatology, pediatric cardiology, obstetrics, and nursing simultaneously, makes communication and role clarity especially important and especially difficult to capture in narrative notes.

The methodology described by Thomas and colleagues involves recording delivery room events with cameras positioned to capture the infant, the resuscitation team, and available monitors, with audio capturing verbal commands, heart rate announcements, and medication preparation. Trained reviewers then code the recordings against structured checklists, often second-by-second, generating a timeline of interventions that can be aligned with physiological data from the monitors. Inter-rater reliability is established through independent dual coding of subsets of recordings. This produces a granular dataset: time from birth to initial assessment, time to adequate heart rate detection, duration and quality of positive pressure ventilation, oxygen concentration used, timing of prostaglandin administration when indicated, and the frequency of deviations from the pre-delivery care plan. None of these elements can be reconstructed with comparable fidelity from chart review alone.

What emerges from such analyses, according to the study’s framing, is a series of insights that chart review structurally cannot provide. Video reveals how often the planned stabilization steps occur in the intended order, and how frequently competing demands, such as an unexpectedly depressed infant requiring immediate ventilation while the cardiac team awaits arrival, force improvisation. It exposes differences between what teams say they will do during prenatal counseling and what actually unfolds. It quantifies interruptions, hesitations, and handoff ambiguities that never reach the medical record. And it provides a basis for constructive, non-punitive debriefing, which many centers that have adopted video review cite as one of its greatest values: teams see themselves as others see them, and targeted coaching follows naturally.

The implications for cardiac neonates are particularly significant because of the population’s fragility and the centrality of early physiology to long-term outcomes. Studies of infants with ductal-dependent lesions have shown that delays in prostaglandin infusion or inappropriate oxygen exposure in the delivery room can initiate a cascade of end-organ injury that shapes neurodevelopmental trajectories long before surgical repair. Preoperative clinical status at the time of surgery is one of the strongest predictors of outcomes in single-ventricle palliation and other complex repairs. If video-based assessment identifies modifiable delivery room practices, delayed recognition of cyanosis, suboptimal ventilatory strategy, medication preparation delays, communication failures between subspecialty services, then it offers a direct lever on downstream outcomes for a population in whom even small physiological improvements may compound over a lifetime.

The study also speaks to a broader methodological transition in perinatal quality improvement. The traditional quality cycle, in which chart-based audits feed committee review and revised protocols, has produced genuine but incremental gains. Video-based assessment closes a feedback loop that has historically been open, replacing inference with observation. In adult medicine, this transition has already changed practice; in neonatology, ethical and logistical barriers, including consent, privacy, storage, and the emotional weight of recording the most vulnerable moments of a family’s life, have slowed adoption. The Journal of Perinatology paper contributes to the growing evidence that these barriers can be managed and that the scientific yield justifies the effort, particularly for high-risk subpopulations where delivery room performance is a decisive determinant of trajectory.

There are, of course, important caveats that the authors and the field must navigate. Video review is resource-intensive; coding recordings requires trained personnel and time. Single-center studies may reflect local team structures, staffing models, and equipment that do not generalize. The presence of cameras, even with staff habituation, can alter behavior, although evidence suggests this effect attenuates quickly. Consent processes must be transparent and must address the possibility that recordings could surface deficiencies in care. And most fundamentally, video identifies what happened, not always why; linking observed deviations to outcomes requires larger, multicenter cohorts with adequate follow-up. The current study should be understood as an early and careful step in that direction, establishing feasibility and highlighting the magnitude of the gap between documentation and reality rather than definitively quantifying outcome associations.

For clinicians in fetal cardiac programs, the practical message is sobering but constructive. The prenatal diagnosis, the delivery planning meeting, and the scripted stabilization plan are necessary but not sufficient. Execution in the delivery room is a distinct skill set, one that can be rehearsed through simulation, refined through video-informed debriefing, and monitored with objective metrics. For families, the study is a reminder that the highest standard of care for a baby with prenatally diagnosed heart disease involves not only expert imaging and surgical planning but disciplined attention to the first minutes of life, where the transition from fetal to neonatal circulation determines whether the carefully constructed plan has a chance to succeed. And for the research community, the work by Thomas, Trulsen, Levy, and their colleagues adds congenital heart disease to the list of conditions for which the delivery room recorder may prove as informative as the chart, and considerably more honest.

As video-based assessment continues to spread through neonatology, the field will face choices about how widely to record, how to govern the data, and how to convert observation into sustained practice change. What this study makes clear is that for newborns with congenital heart disease, a population in whom every minute and every concentration of inspired oxygen matters, understanding stabilization “beyond chart review” is not a luxury but a necessity. The recordings reviewed here suggest that the gap between what is documented and what is done is wide enough to matter, and closing that gap may be one of the most direct paths available to improving outcomes for these infants in their most vulnerable hours.