Non‐Scarred Uterine Rupture in the Middle Stages of Pregnancy: A Case Report

ABSTRACT

Uterine rupture, a severe complication endangering pregnant women and fetuses, typically occurs in late pregnancy or during delivery. Complete uterine ruptures are exceedingly rare in women without uterine scars. However, the adjustment of China's fertility policy has contributed to the escalating incidence of uterine rupture. Herein, we report a case of a non‐scarred uterine rupture in the middle stages of pregnancy that was successfully managed with surgical intervention, after proving to be a diagnostic challenge.

Key Clinical Message

This case details a 26‐week non‐scarred pregnant patient with severe abdominal pain, who was diagnosed with complete uterine rupture through surgery. The successful treatment underscores the importance of timely surgical intervention to improve diagnosis and maternal and infant prognosis in resource‐limited areas.

1. Introduction

Uterine rupture, a severe complication endangering pregnant women and fetuses, typically occurs in late pregnancy or during delivery. Complete uterine rupture in pregnancy involves the entire uterine wall, including the serous and amniotic layers, with the rupture communicating with the abdominal cavity, potentially allowing pregnancy tissue or the fetus to enter [1]. In resource‐poor nations, uterine rupture is commonly associated with obstructed labor, injudicious obstetric interventions/manipulations, lack of antenatal care, grand multiparity, and poor access to emergency obstetric care [2]. Uterine ruptures are exceedingly rare in women without uterine scars [3]. However, a study spanning 40 years noted a rise in uterine rupture incidence in non‐scarred uterus from 0.9/10,000 to 6.1/10,000 [4]. The adjustment of China's fertility policy and the increased use of vaginal trial labor for scarred uterus have contributed to the escalating incidence of uterine rupture [5]. This article examines the diagnostic and treatment procedures of a mid‐pregnancy non‐scarred uterine rupture case, aiming to improve early identification of uterine rupture by clinicians, particularly in regions with limited medical resources. This case occurred in Ximeng Wa Autonomous County, Yunnan Province, China. The women in this area have a weak awareness of women's health care and often fail to have regular prenatal check‐ups during pregnancy. The commitment of resource‐limited areas to maintaining a healthy and productive female population will ultimately determine success or failure [2]. The goal is to enable prompt diagnosis, standardized treatment, and prevention of adverse maternal and neonatal outcomes. This case has obtained the patient's written informed consent.

2. Case History

A 32‐year‐old woman was admitted to the emergency department on the evening of July 8, 2025, presenting with a history of amenorrhea lasting over 6 months and abdominal pain for 1 day. She reported a regular menstrual cycle with her last menstrual period on January 4, 2025, and an estimated date of confinement on October 11, 2025. Approximately 16 weeks postmenstrual age, she underwent registration at the county maternal and child health hospital. On July 7, she experienced sudden, dull abdominal pain of unknown etiology, with unclear interval and duration, which was initially disregarded. Around 8 p.m. on July 8, she developed severe anterior, middle, and upper abdominal pain, evolving into continuous abdominal pulling pain that exacerbated progressively. This was accompanied by palpitation, difficult breathing, and profuse sweating. She denied chest and back radiation, nausea, vomiting, anal distension, paroxysmal abdominal tightness, vaginal bleeding, or discharge. Throughout the pregnancy, she reported good mental status, appetite, and sleep, with normal bowel and bladder habits. Her weight gain remains unspecified.

The patient has a history of five pregnancies and two deliveries, both of which were natural. She has denied experiencing postpartum hemorrhage and has undergone three induced abortions. There were no complications during the operation. Upon admission, the patient's vital signs were as follows: temperature of 36.7°C, heart rate of 90 beats per minute, respiratory rate of 24 breaths per minute, blood pressure of 130/85 mmHg. She appeared alert with a flushed complexion, was in a semi‐recumbent position, and had cold, clammy skin. Physical examination revealed abdominal distension resembling a six‐month pregnancy, abdominal muscle rigidity, diffuse abdominal tenderness, absence of uterine contractions or fetal heart sounds, and absence of blood or vaginal discharge. The patient was unable to undergo internal examination due to pain hindering position changes for cooperation.

3. Differential Diagnosis, Investigations and Treatment

Bedside ultrasound at 22:51 indicated the following findings: (1) At 26 weeks of gestation, a single fetus was observed in a transverse position with no detectable fetal heart activity and a maximum amniotic fluid depth of 4.3 cm; (2) Presence of a single umbilical artery; (3) Identification of heterogeneous echo zones (approximately 11.0 × 7.4 cm) within the placenta, necessitating further investigation to determine their nature (placental abruption?). Considering the patient's detailed medical history, physical examination, and additional test results, placental abruption is a potential diagnosis, although uterine rupture cannot be excluded. It is recommended to liaise with the departments of anesthesiology, blood transfusion, ICU, and other pertinent units to draw up an urgent laparotomy exploration.

The patient was transported to the operating room at 23:20. By 23:23, both veins were accessed, a urinary catheter was inserted, and blood samples were collected for a comprehensive array of tests. Fetal heart activity was not detected. The operation commenced at 23:34 under general anesthesia with tracheal intubation. An accumulation of dark red blood measuring approximately 2500 mL was observed in the abdominal cavity. The uterus measured 15 × 13 × 8 cm, displaying a 12 cm rupture at its base obstructed by a blood clot and placenta (Figure 1). The uterus appeared pale and soft, while both adnexa exhibited a normal appearance. The fetus, located in the abdominal cavity, was nonviable and subsequently removed along with the placenta (Figure 2). Weak uterine contractions and significant bleeding from the incision were noted during the procedure. Binding the lower segment of the uterus with a tourniquet resulted in reduced bleeding from the incision, although uterine contractions remained inadequate. Administration of 250 μg of Carboprost trometamol and 0.2 mg of ergonovine maleats failed to improve uterine contractions. Subsequent to obtaining informed consent from the family, a subtotal hysterectomy and bilateral salpingectomy were performed. The operation was successfully concluded on July 9, at 03:45. Throughout the procedure, the patient received 10 units of cryoprecipitate, 5 units of alloleukocytic suspended red blood cells, and 600 mL of frozen plasma. Intraoperative blood loss amounted to 500 mL, with an additional 2500 mL from peritoneal hemorrhage, totaling 3000 mL. Fluid replacement reached 4500 mL, while urine output measured 1300 mL. By 04:10, the patient had been transferred to the ICU with tracheal intubation in place, and received symptomatic supportive treatment.

FIGURE 1.

Uterine rupture site.

FIGURE 2.

Fetal and placental tissues.

4. Conclusion and Results

Postoperative pathological examination revealed dilated blood vessels within the uterine muscle walls, along with blood and inflammatory cell infiltration in the local interstitium. Fibrinous exudates and decidual‐like interstitial cells were present, with no atypical cells, villi, or trophoblast cells identified. The patient's postoperative course was uneventful, and she was discharged 9 days after surgery in stable condition.

5. Discussion

5.1. High‐Risk Factors for Uterine Rupture During Pregnancy

Uterine rupture primarily affects women with a prior history of uterine surgery. The incidence of uterine rupture in a scarred uterus resulting from cesarean section ranges from 0.3% to 1% [5]. All the surgical factors that cause damage to the uterine muscle layer during gynecological surgeries are high‐risk factors for uterine rupture during pregnancy, such as myomectomy, tubal interstitial resection, uterine horn resection, uterine reshaping surgery, etc [6, 7, 8]. Factors such as uterine malformations, polyhydramnios, twin pregnancies, macrosomia, maternal age, gestational age, fetal malpresentation, inappropriate drug use (e.g., oxytocin, misoprostol), trauma, placental disorders, etc., can also contribute to uterine rupture during pregnancy and labor [9, 10, 11, 12]. Women with a history of induced abortion, curettage, or hysteroscopic surgery may have compromised myometrium integrity, potentially leading to concealed uterine perforation, which poses a risk for uterine rupture [13]. In this case, the patient had undergone three previous induced abortions and denied a history of uterine perforation. During the procedure, the placenta was identified at the ruptured fundus of the uterus, raising the possibility of prior undetected uterine perforation as a contributing factor to the uterine rupture.

5.2. Clinical Manifestations and Diagnosis of Uterine Rupture During Pregnancy

The typical clinical manifestations of uterine rupture consist of abnormal fetal heart rate, abdominal pain, and vaginal bleeding. Additional clinical signs include abnormal patterns in electronic fetal heart rate monitoring, cessation of uterine contractions, tachycardia, hypotension, syncope or shock in pregnant women, and alterations in abdominal contour [14]. Rare instances have been documented where severe maternal and infant complications arise from uterine rupture during pregnancy despite the absence of evident clinical symptoms [15]. A study shows that the perinatal mortality rate for patients with non‐scarred uterine rupture is 40%, and suggests that these cases are often overlooked, leading to delayed diagnosis [16]. The diagnosis of uterine rupture in clinical settings typically involves a combination of the patient's clinical manifestations and imaging examinations. While ultrasound serves as the preferred imaging modality, disparities in the proficiency of ultrasound operators in underdeveloped regions may lead to overlooked diagnoses of minor uterine ruptures. Despite initial bedside ultrasound findings indicating heterogeneous echo areas in the placental parenchyma upon admission, suggestive of placental abruption, the hospital promptly initiated the green channel and multidisciplinary collaborative rescue. Subsequently, the diagnosis was confirmed through intraoperative exploration. This case underscores the critical importance of clinical workers' diagnostic and therapeutic strategies, as well as their first aid proficiency, in ensuring the timely identification and management of uterine rupture, rather than relying entirely on auxiliary examinations.

5.3. Treatment and Outcomes of Uterine Rupture During Pregnancy

Uterine rupture can result in adverse outcomes for both mothers and fetuses, including fetal distress, intrauterine fetal demise, hemorrhagic shock, and maternal mortality. The clinical consequences of uterine rupture in pregnancy are primarily influenced by factors such as gestational age, speed of onset, extent and site of rupture, and promptness of medical intervention. Factors such as early gestational age, sudden onset, specific site and size of rupture, as well as delayed diagnosis and treatment, contribute significantly to unfavorable outcomes. Sgayer et al. [17] analyzed 84 cases of spontaneous uterine rupture documented between 1983 and 202, revealing that 72% of ruptures occurred in the uterine body. Furthermore, non‐scar uterine ruptures were more prevalent in developing and underdeveloped nations compared to developed countries. Patients with non‐scarred uterine ruptures and their infants tend to experience poorer outcomes than those with scarred uterine ruptures. This discrepancy may be attributed to the irregular nature of non‐scarred uterine ruptures, which are characterized by a higher density of blood vessels in the myometrium, leading to a heightened risk of rapid hemorrhagic shock. Upon detection of a complete uterine rupture during pregnancy, immediate intervention is imperative, irrespective of fetal viability. Prompt surgical intervention necessitates collaboration with pertinent departments including anesthesiology, neonatology, ICU, and blood transfusion. The primary intervention for uterine rupture involves repair. However, in cases of extensive rupture, irregular rupture edges, severe infection, involvement of critical blood vessels, or incomplete repair feasibility, total hysterectomy may be a suitable option based on intraoperative circumstances.

6. Conclusion

Uterine rupture represents a significant obstetric complication that jeopardizes the safety of both the mother and the infant. Its incidence and severity differ across countries, regions, and time periods. Low‐income countries and regions are particularly susceptible to severe complications due to limited economic and medical resources. A substantial proportion of non‐intrapartum spontaneous uterine ruptures occur in non‐medical settings, where immediate surgical intervention is unavailable. Furthermore, the low incidence of uterine rupture in non‐scarred uteri during pregnancy, combined with the absence of pertinent high‐risk medical history, heightens the risk of missed or misdiagnosis, thereby delaying optimal surgical intervention. Consequently, early identification, timely diagnosis, and treatment of uterine rupture are crucial. In clinical practice, it is essential to enhance the training of medical personnel and to increase their awareness of non‐scarred uterine rupture. Establishing a “highly skeptical” clinical mindset, making full use of limited resources, clearly identifying surgery as the only curative method, and interdisciplinary cooperation are all of crucial importance. Additionally, augmenting investment in medical resources and improving prenatal care supervision are vital for enhancing the prognosis of affected patients and their newborns.

Author Contributions

Mengji Zhang: conceptualization, writing – original draft. Xi Lan: supervision. Yueming Li: resources.

Funding

The authors have nothing to report.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.