Umbilical Vein Elastic Fiber Deficiency as an Emerging Risk Factor for Catastrophic Umbilical Cord Hemorrhage: A Case Report

Abstract

Background

Umbilical cord hemorrhage (UCH) is a rare and fatal event involving the rupture of the umbilical vein. UCH is associated with mechanical reasons, such as cord entanglement, but new evidence suggests congenital structural weakness such as a lack of elastic fibers in the vein wall (umbilical vein dysplasia) as a predisposing factor, though it is not well understood clinically. This case report describes a term breech neonate who died from umbilical cord hemorrhage; autopsy revealed a marked deficiency of elastic fibers in the umbilical vein wall, suggesting a potential association with spontaneous umbilical vein rupture.

Case Report

A 27-year-old woman (G2P0) was admitted at 37⁺² weeks due to premature rupture of membranes (PROM). Ultrasound showed a breech fetus with a nuchal cord. After fetal bradycardia (90 bpm), an emergency cesarean section delivered a live female infant through III-degree meconium-stained amniotic fluid. The Apgar score was 10 at 1, 5 and 10 minutes. At 12 minutes, she developed cyanosis and dyspnea with an SpO₂ of 80%. Endotracheal suctioning yielded 2 mL of meconium; however, heart sounds remained weak and spontaneous respiration was inadequate. Resuscitation failed, and she died on day 2. Autopsy revealed umbilical cord hemorrhage secondary to umbilical vein rupture, and histochemical staining demonstrated a significant deficiency or absence of elastic fibers in the umbilical vein wall.

Conclusions

This case suggests that congenital elastic fiber deficiency may predispose to spontaneous umbilical vein rupture and sudden neonatal death, even in the presence of initially reassuring Apgar scores. It highlights the potential value of routine elastin staining in perinatal autopsies and supports further research into the prevalence and genetic basis of this dysplasia.

Introduction

Umbilical cord hemorrhage (UCH) is a rare but catastrophic obstetric emergency characterized by spontaneous rupture of the umbilical vein, leading to hematoma formation within Wharton’s jelly. The expanding hematoma can compress the adjacent umbilical arteries and abruptly disrupt fetoplacental circulation, resulting in acute fetal distress and, in severe cases, perinatal death.¹ Although mechanical factors such as cord entanglement-an established risk in breech presentations-have long been recognized as precipitants of UCH, emerging evidence suggests that structural vulnerabilities of the umbilical vessel wall may play a more fundamental role. Among these, elastic fibers are critical for maintaining the structural integrity and biomechanical resilience of the umbilical vein. A marked deficiency or near-complete absence of elastic fibers in the vein wall-a form of umbilical vein dysplasia-severely compromises vascular integrity and resistance to mechanical stress, thereby predisposing the vessel to spontaneous rupture even in the absence of overt cord pathology. However, this condition remains poorly recognized and is likely underdiagnosed in the setting of sudden and unexpected perinatal death, particularly when clinical risk factors such as abnormal presentation are present and Apgar scores are initially reassuring.

This case report describes the tragic death of a term breech-presenting neonate who died from a rare and possibly underdiagnosed cause of perinatal mortality following severe clinical deterioration. This case illustrates the need for systematic histopathological examination, including elastin-specific staining, of umbilical cords in unexplained fetal and neonatal deaths to detect such structural anomalies and to guide future prevention strategies.

Case Presentation

A 27-year-old woman, secundigravida, presented with a negative general and obstetric history. The patient was admitted at 37 weeks and 2 days of gestation due to premature rupture of the fetal membranes, leading to vaginal discharge that lasted for 2 hours. The color ultrasound showed the fetus was breech, the umbilical cord wrapping around the neck in a single loop. The electronic fetal heart rate monitor showed reactive non-stress test (NST) with a fetal heart rate of 135 bpm. Minutes after admission, the obstetrician measured the fetal heart rate 90 bpm and performed lower uterine segment caesarean section on the same day. The amniotic fluid was outflow of degree III. A live female infant was delivered by breech traction, with a birth weight of 3300 grams (g). Apgar scores were consistently 10 at the first, fifth and tenth minute after birth. Dyspnoea with moaning and skin cyanosis was observed 12 minutes after birth, and transcutaneous oxygen saturation was maintained at 80%. Tracheal intubation was performed promptly for fetal fecal suction, extracting around 2 mL of fecal contaminated amniotic fluid. Heart sounds were faint and spontaneous respiration was weak. Positive pressure ventilation using a T-piece face mask for connection to an endotracheal tube failed and the patient died on the second day of birth.

An autopsy was conducted on the fifth day following the neonate’s death. The neonate was female, with a weight of 3100 g and a length of 50 cm. The placenta consisted of two lobes with a combined weight of 640 g. The lobe connected to the umbilical cord had dimensions of 11.0 cm×8.0 cm×2.0 cm, while the other lobe measured 11.0 cm×9.0 cm×2.0 cm. The umbilical cord measured 46 cm in length and 1.0 cm in diameter, attaching to the periphery of one lobe, characterized as a “racket-shaped placenta”. The umbilical cord exhibited notable spiral curling and subamniotic hemorrhage, extending from the placental attachment margin to a distance of 3.0 cm (Figure 1A). Following formalin fixation, the umbilical cord was transversely sectioned, revealing edema and hemorrhage within the Wharton’s jelly, along with a dilated and congested umbilical vein (Figure 1B). The umbilical vein of the umbilical cord at the placental attachment margin exhibited an absence of the muscular layer, segmental thinning, and rupture of the vessel wall (Figure 2A), along with peripheral Wharton’s jelly hemorrhage extending to the subamniotic membrane by microscopic examination. Staining of elastic fibers revealed a significant reduction or complete absence of the purple-stained elastic fibers (Figure 2B). Microscopic analysis of the lungs demonstrated uniformly pink-stained small lamellar keratinized epithelium, and the presence of meconium corpuscles within the alveolar lumens (Figure 3A). Immunohistological staining for cytokeratin (CK) revealed yellow or brownish-yellow expression of keratinized epithelium within the alveolar lumens (Figure 3B).

Figure 1.

Gross findings of the placenta and umbilical cord. (A) The placenta was bilobed. The umbilical cord, which inserted marginally into one lobe (characteristic of a “racket-shaped placenta”), showed slight spiral curling and subamniotic hemorrhage. (B) Formalin-fixed umbilical cord cross-section: dilated, congested umbilical vein with edema and hemorrhage in the surrounding Wharton’s jelly.

Figure 2.

Microscopic observations of the umbilical vein. (A) The wall of the umbilical vein exhibited segmental thinning, rupture, and hemorrhage as observed through HE staining. (B) Elastic fiber staining revealed focal loss of the internal elastic lamina and medial elastic fibers. The scale bar, 200 µm.

Figure 3.

Microscopic observations of the lung. (A) HE staining demonstrated uniformly eosinophilic squamous epithelial squames within the alveolar spaces. (B) CK immunohistochemistry demonstrated distinct yellow or brownish-yellow staining of keratinized epithelial material within the alveolar lumens. The scale bar, 200 µm.

Discussion

Elastic fibers are essential structural components of the umbilical vein wall, providing the vessel with the elasticity and tensile strength required to withstand the mechanical stresses of fetal movement, uterine contractions, and cord compression during pregnancy and labor. In the presented case, the special staining for elastic fibers revealed a near‑complete absence of these crucial structural components at the site of rupture. This intrinsic weakness rendered the umbilical vein exquisitely vulnerable to mechanical failure. The mechanism involves the rupture of the weakened vessel wall, leading to an acute intramural and extramural hemorrhage within Wharton’s jelly. This hematoma rapidly expands, exerting a compressive, tourniquet-like effect on the adjacent, higher-pressure umbilical arteries, leading to a sudden and catastrophic cessation of fetoplacental circulation. The genetic underpinnings of isolated umbilical vein elastic fiber deficiency are not yet well-elucidated. However, it is logical to situate this pathology within the broader spectrum of inherited connective tissue disorders affecting elastin, such as those caused by mutations in the elastin (ELN) gene or other genes involved in elastogenesis.² While systemic manifestations such as supravalvular aortic stenosis^3,4 or cutis laxa^5,6 were not noted in this case, it is plausible that a localized or mosaic genetic defect could result in such a focused, yet lethal, vasculopathy.

Spontaneous umbilical vein rupture with umbilical cord hematoma is a rare but well-recognized cause of perinatal death. Several etiologies and associated conditions have been reported, including coagulation disorders,⁷ infectious conditions,⁸ and post-maturity.⁹ Nevertheless, in the majority of cases, no definitive cause is identified. In a 2018 review, Scutiero et al described 11 cases of spontaneous umbilical cord hematoma, of which 7 had no demonstrable pathological condition.¹⁰ The present case is notable for the near-complete absence of elastic fibers specifically at the site of venous rupture, a finding that provides a clear structural explanation for the hematoma and distinguishes it from previously reported cases. This suggests that at least a subset of “idiopathic” umbilical cord hematomas may in fact be attributable to occult elastic fiber dysplasia, and that routine elastin staining may uncover additional cases, thereby supporting its inclusion in the standard histopathological evaluation of umbilical cords in cases of unexplained perinatal death.

Although meconium aspiration was the immediate cause of death in this case, we propose that the underlying cause was umbilical vein rupture secondary to congenital elastic fiber deficiency. The pathological cascade began with spontaneous rupture of the structurally weakened umbilical vein, resulting in acute umbilical cord hemorrhage. The expanding hematoma within Wharton’s jelly exerted a compressive effect on the adjacent umbilical arteries, leading to abrupt fetal compromise. This acute intrauterine hypoxia triggered fetal gasping reflexes and meconium passage, culminating in meconium aspiration. Thus, while meconium aspiration was the direct mechanism leading to death, it was itself the consequence of the elastic fiber deficiency, which initiated the fatal cascade. Breech presentation and the other mechanical factors discussed below likely acted as aggravating contributors by increasing mechanical stress on the vulnerable vessel wall.

While the congenital vessel wall weakness was the primary vulnerability, several other factors documented in this case likely contributed to the final catastrophic event. First, the placental morphology was abnormal, described as a bilobed placenta with a “racket-shaped” cord insertion. A bilobed, or bipartite, placenta is a known morphological variant associated with an increased risk of other anomalies, most notably abnormal umbilical cord insertions. The “racket-shaped” description corresponds to a marginal cord insertion, where the cord attaches at the placental edge rather than centrally. This type of insertion is biomechanically suboptimal, as the anchoring point is less protected and subject to greater tensile and shearing forces during fetal movement and uterine contractions. A 2022 case report highlighted a bilobed placenta with a furcate cord insertion, underscoring the co-occurrence of these abnormalities.¹¹ The combination of a bilobed structure and a marginal insertion in this case would have concentrated mechanical stress at the exact point where the umbilical vein was congenitally weakest, creating a “perfect storm” for rupture. Second, the fetus was in a breech presentation. Breech presentation itself increases the risk for umbilical cord complications, most notably cord prolapse.¹² While prolapse did not occur here, the dynamics of a breech fetus, particularly during labor or with ruptured membranes, may subject the umbilical cord to different and potentially greater stretching and torsion forces compared to a cephalic presentation. Third, the umbilical cord itself was noted to have “notable spiral curling”. While coiling is a normal feature, hypercoiling is a recognized risk factor for adverse perinatal outcomes, as it can predispose the cord to torsion and vascular compromise.¹³ The combination of breech presentation, marginal insertion, and hypercoiling would have amplified the mechanical stress on the fragile umbilical vein, precipitating its rupture.

From a clinical perspective, a key feature of this case is the so-called “Apgar paradox”: the newborn had normal Apgar scores of 10 at one, five, and ten minutes. This can be misleading, as the Apgar score primarily reflects the infant’s cardiopulmonary status at the moment of birth and has limited sensitivity in detecting underlying metabolic disturbances. Even a normal score does not exclude significant hypoxia and metabolic acidosis, which can develop rapidly, for instance, under sustained arterial compression.¹⁴ The finding of Grade III meconium-stained amniotic fluid (MSAF)—characterized by dark green or black, thick, particulate fluid—and the subsequent histopathological confirmation of meconium aspiration (keratinized epithelium and meconium corpuscles within alveolar lumens) provide direct evidence of such an intrauterine hypoxic insult. The meconium passage is a symptom of fetal compromise, often triggered by acute hypoxia and vagal stimulation.¹⁵ This case underscores that meconium staining, particularly Grade III, serves as a critical marker of fetal distress that may not be reflected in the Apgar score. Consequently, the presence of thick meconium mandates continuous intrapartum monitoring and preparedness for skilled resuscitation.¹⁶ However, contemporary management emphasizes that the newborn’s condition at birth, not the meconium grade itself, dictates the intervention. This aligns with the principle illustrated by the Apgar paradox: routine umbilical cord blood analysis (pH, blood gases, lactate) remains essential for the accurate assessment of perinatal hypoxia-acidosis,¹⁷ a step unfortunately omitted in this case. The reasons for this omission are multifactorial. At delivery, the newborn had reassuring Apgar scores of 10 at 1, 5, and 10 minutes, and there were no immediate clinical signs suggestive of fetal compromise that would have prompted cord blood sampling. In addition, umbilical cord blood gas analysis is not currently performed as a routine procedure for all deliveries at our institution, particularly when the intrapartum course appears uneventful and the newborn is vigorous. When the infant’s condition deteriorated suddenly at 12 minutes of age, the clinical team appropriately prioritized resuscitative measures, and the opportunity to obtain a representative cord blood sample had passed. In retrospect, the presence of Grade III meconium-stained amniotic fluid should have prompted cord blood gas sampling regardless of the normal Apgar scores. We acknowledge this as a limitation and emphasize that cord blood gas analysis should be considered in any delivery complicated by meconium staining, abnormal fetal heart rate, or other risk factors, even when the newborn appears healthy at birth.

This case highlights a critical challenge in modern obstetric practice: the management of a patient with multiple, co-existing risk factors in the absence of specific guidance. The root pathology—congenital elastic fiber deficiency—is undetectable antenatally, as ultrasound cannot assess the microscopic integrity of the umbilical cord vasculature. While current guidelines from major bodies like American College of Obstetricians and Gynecologists (ACOG) and Royal College of Obstetricians and Gynaecologists (RCOG) provide clear protocols for isolated conditions such as breech presentation or cord prolapse, a significant management gap exists for the combination of breech presentation with antenatally detected cord abnormalities (eg, marginal insertion or hypercoiling).¹⁸ This case illustrates how the confluence of several, potentially minor, risk factors can lead to a catastrophic outcome when an underlying vulnerability is present. This underscores a need for better risk stratification. Currently, a lack of retrospective data on optimal delivery timing and mode for such multifactorial scenarios prevents the development of evidence-based management protocols.

From a preventive perspective, although congenital elastic fiber deficiency is not currently detectable antenatally, several measures may reduce the risk of adverse outcomes in future pregnancies. For the mother in this case, we recommend detailed prenatal ultrasound assessment of umbilical cord morphology, including cord insertion site, coiling index, and vessel integrity, as well as consideration of elective cesarean delivery given the combination of breech presentation and suspected cord structural anomalies. For pregnant women in general, this case highlights the importance of recognizing the synergistic effect of multiple minor risk factors—such as marginal cord insertion, hypercoiling, and abnormal presentation-which may warrant heightened intrapartum surveillance. Furthermore, we strongly recommend that elastin-specific staining become a routine component of perinatal autopsy in cases of unexplained stillbirth, neonatal death, or umbilical cord hematoma, as this may uncover similar cases and inform recurrence-risk counseling. Future research should focus on the genetic basis of isolated umbilical vein elastic fiber deficiency and the development of antenatal screening modalities, such as high-resolution ultrasound or magnetic resonance imaging, to detect vascular wall fragility.

Conclusion

In summary, this case describes a rare mechanism of neonatal death-spontaneous umbilical vein rupture associated with congenital elastic fiber deficiency-with a clinical presentation characterized by initially reassuring Apgar scores that masked a rapidly fatal course. The postmortem identification of near-complete elastic fiber loss at the rupture site was essential in establishing the diagnosis. This finding suggests that elastin-specific staining may be valuable in the histopathological evaluation of umbilical cords in selected cases of unexplained fetal or neonatal death. For the family, the precise postmortem diagnosis provided a clear explanation for the unexpected loss, alleviated potential guilt, and informed recurrence-risk counseling. However, given the single-case nature of this report, an unequivocal recommendation for routine elastin staining in all perinatal autopsies would require further evidence. Future studies should focus on the prevalence and genetic basis of umbilical vein elastic fiber deficiency, with the ultimate goal of improving risk stratification and prevention of such tragedies.

Ethics Approval and Consent to Participate

This work was approved by the Ethics Committee of Institute of Evidence Law and Forensic Science, China University of Political Science and Law, and was performed in accordance with the 1964 Declaration of Helsinki.

Consent Statement

Written informed consent was obtained from the patient for publication of this case report and the accompanying images.

Disclosure

The author reports no conflicts of interest in this work.