1. Introduction
Conjoined twins is defined as twins that are physically fused in utero and at birth [1]. Conjoined twins are a rare congenital anomaly, occurring in approximately 1 in 50,000 pregnancies [2]. The highest incidence is noted in Africa and Asia, with ratios of 1 in 14,000 and 1 in 25,000 pregnancies, respectively [2]. The incidence of parasitic conjoined twins is exceedingly rare, occurring in fewer than 1 in 1 million live births [3]. Between 1975 and 2017, Dr. Soetomo Hospital in Surabaya documented 85 cases of conjoined twins, of which 62 were female and 23 were male [4]. Unfortunately, 48 of these infants did not survive [4]. A notable case during the COVID-19 pandemic described the successful separation of 2.5-month-old omphalopagus-type female conjoined twins in Indonesia [5]. However, the incidence of parasitic conjoined twins in Indonesia has not been reported.
The management of conjoined twins focuses on reducing mortality and morbidity, with anatomical diagnosis as the foundation for separation surgery. Additional considerations evaluated in the decision-making process include the newborn's health status at birth, specifically the condition and quantity of vital organs, the APGAR score, and the likelihood of survival post-surgery [6]. Reconstruction planning should commence immediately upon prenatal diagnosis. These cases are intricate and require extensive preoperative and intraoperative planning [6,7]. Therefore, tertiary hospitals are ideally suited for the management of conjoined twins. Separation surgeries typically involve a multidisciplinary team, including pediatric surgeons, pediatricians, neurosurgeons, rehabilitation specialists, and nutritionists [6,7].
According to the authors' experience, early separation can be lifesaving, especially for the healthier twin. Nevertheless, there is a lack of consensus regarding the optimal timing for separation surgery in parasitic conjoined twins [8]. Early separation tends to result in better outcomes for deformity correction and a lower incidence of psychological complications, compared to separation at later stages of growth [8]. Conversely, deferring the procedure until the patients have matured may reduce surgical risks [8]. Ethical considerations are particularly pertinent when one of the twins is non-viable. In the case of the parasitic conjoined twins discussed here, separation was performed promptly after obtaining ethical approval from the Department of Forensic and Medico-Legal Services at our institution. This manuscript was prepared in accordance with the CARE guidelines
A 31-week pregnant woman presented to the hospital with a twin pregnancy and was diagnosed with a fetal emergency. Initially, the woman received her first antenatal care (ANC) at 26 weeks of gestational age (GA) from a midwife, who noted that the uterine fundal height was significantly larger than expected for the GA. As a result, the woman was referred to our hospital for further evaluation and management. At our center, the woman underwent her first ANC ultrasound at 27 weeks of GA. Fetomaternal and 3D ultrasound imaging revealed that the two live fetuses were conjoined abdominopagus twins sharing a single liver (Fig. 1). The woman was also diagnosed with preeclampsia and received appropriate management. At 31 weeks of GA, the patient returned to our center for a routine ANC where only one fetal heartbeat was detected, necessitating urgent delivery.
Fig. 1. Fetomaternal ultrasound revealing conjoined twins sharing a single liver (red arrow).
A caesarean section was performed, resulting in the delivery of two female neonates weighing 2700 g in total. Neonate A was born with an APGAR score of 7/9, and Neonate B was a stillbirth (Fig. 2). Ventriculomegaly was present in neonate A, while neonate B exhibited a variety of congenital anomalies, such as bilateral cleft lip, hypodactyly, hygroma colli, hydrocephalus, and hydrops fetalis. The contents of the parasite were unable to be identified due to religious and socio-cultural considerations. Autopsies and additional examinations of deceased neonates are not permitted without a strong indication, such as a legal requirement.
Fig. 2. The set of female conjoined twins: a living Neonate A (left) and a stillbirth Neonate B (right).
The stabilization of Neonate A was managed by a pediatric anesthetist in collaboration with the neonatology team. The airway and breathing were assessed by the pediatric anesthetist, and respiratory support was provided with supplemental oxygen at 2 L per minute via a nasal cannula. The neonatology team reviewed hemostasis and the cardiopulmonary system, and the complete blood count results were within normal limits. Due to the urgent nature of the case, thorough diagnostic testing was not performed preoperatively. With approval from the forensic and medical-legal teams, separation surgery was immediately carried out by the pediatric surgery team.
Two hours following the pregnancy termination, a separation surgery was performed by three senior pediatric surgeons who are experienced in conjoined twin separation surgeries. Abdominal wall separation was performed during the surgery, creating a 15 cm × 12 cm defect. The surgical findings corroborated the prenatal ultrasound results, revealing that the twins shared a single liver, with vascular connections confined exclusively to the liver. Our team did not find any malrotation, intestinal atresia, or fused bowel. The abdominal wall was closed with an advanced flap technique, followed by an all-layer suturing method using monofilament. The liver of the healthy infant was normal, and the conjoined portion of the liver was relatively small, facilitating a smooth skin closure. The primary challenge faced during the surgery was bleeding control. To manage this, we utilized a harmonic scalpel to separate the fused tissues while minimizing blood loss. The operation was successfully completed in approximately 70 minutes without any complications or adverse incidents.
Postoperative stabilization of Neonate A was done in the neonatal intensive care unit (NICU). Subsequently, a comprehensive diagnostic work-up was conducted. Neonate A was diagnosed with a patent ductus arteriosus and received intravenous indomethacin. On the third day postoperatively, Neonate A remained hospitalized in the NICU, supported by an A/C ventilator in pressure mode, with 60 % FiO2 and PEEP 6. Normal vital signs were observed during the physical examination, and all laboratory results were within normal limits. A 30 mL packed red blood cell (PRC) transfusion was administered, along with a 30 mL plasma transfusion, FFP, and vitamin K given for 24 hours at 0.5 mL per hour to support circulation and coagulation. In addition, a prophylactic antibiotic regimen consisting of ampicillin-sulbactam (34 mg every 6 h) and gentamicin (7 mg every 36 hours) was administered. A follow-up examination at one month revealed that the patient was in stable condition and doing well.
3. Discussion
This report presents a case of conjoined abdominopagus heteropagus twins, one of whom was born alive, while the other died in utero prior to delivery. Asymmetrical or "heteropagus" conjoined twins refer to a type of conjoined twins in which one twin is significantly more developed and is attached externally to a fetus with severe congenital anomalies. The more fully developed twin is referred to as the "autosite," while the underdeveloped, defective twin is known as the "parasite" [10]. According to Mathur et al. [11] the management of conjoined twins is not only limited to surgical separation but also involves antenatal evaluation, mode of delivery planning, and preoperative planning. In our case, the fetuses were initially diagnosed as conjoined abdominopagus twins based on the ultrasound scan at 27 weeks of GA. However, during the routine ANC at 31 weeks of GA, only one fetal heartbeat was detected, warranting an emergency caesarean section. Upon delivery, we found that the conjoined twins were asymmetric, with the deceased twin (Neonate B) presenting with more severe congenital anomalies and was parasitic to her autosite (Neonate A).
The patients in our study shared similar characteristics with the patients described in previous studies by Bansal et al. [6], Mathur et al. [11], and Takrouney et al. [12], the majority of which were abdominopagus parasitic twins. Researchers reported this type as the most common form of parasitic conjoined twins [1,2]. However, the twins in our study had a lower birth weight, likely due to earlier gestational age upon delivery in addition to racial variation.
Following the pregnancy termination, the initial management in this case was primarily focused on the stabilization of Neonate A. After achieving stabilization, it was crucial to identify the most suitable management strategy. The primary objectives of surgery for parasitic conjoined twins include postnatal survival, normal growth, and the development of the patients [4,13,14]. The demise of one conjoined twin is an indication for emergency surgical separation [15]. The surviving twin is typically at risk of mortality due to the release of toxins as well as sepsis and shared organ failure caused by the deceased twin [15,16]. Mathur et al. [11] recommended immediate surgery, considering the potential risks the parasite poses to the autosite. Since the parasite relies on the autosite's blood supply, the autosite's heart experiences significant strain, which can lead to circulatory and hemodynamic failure. Takrouney et al. [12] reported a case in which the parasitic twin's death prior to surgery led to sepsis in the surviving twin [12]. This condition was attributed to the poor vascularization of the parasite, despite its connection to the autosite [12]. Carlson et al. [15] noted that numerous conjoined twins who were never separated passed away conjoined, often within hours of each other. In the present case, Neonate B was found to have died in utero with an unknown exact time of death, raising concerns that various pathophysiological processes may have already been initiated, potentially endangering the life of the surviving twin. Given the urgency, we prioritized early separation surgery to optimize the chances of survival for Neonate A. Consequently, comprehensive preoperative diagnostics were not performed, as they would have delayed the timing of the surgery. Before proceeding with an early separation surgery, we had obtained the parents' informed consent as well as permission from the Forensic and Medicolegal team to operate on a deceased infant.
Although various studies suggested early separation in cases of parasitic conjoined twins, Bansal et al. [6] recommended that surgical intervention for parasitic conjoined twins be postponed for 6–12 months after birth. The purpose of this delay is to facilitate organ maturation and make any potential dysfunctions visible prior to surgery. Bansal et al. [6] also highlighted several intraoperative complications, including desaturation, hypotension, and bradycardia. In these cases, multiple interruptions were necessary during the surgery to achieve patient stabilization [6]. However, the benefit of such a delay in reducing intraoperative complications remains unproven.
Other factors to consider in choosing between immediate or deferred surgery are the psychological and social aspects. Studies have shown that delaying operations on conjoined twins is typically associated with more significant psychological impacts compared to immediate surgeries [7]. Furthermore, delayed operations are often linked to negligence [17].
In recent years, technological advancements have expanded the array of choices available for the diagnosis and management of parasitic joined twins. Hill et al. [18] reported that suspicion of conjoined twins may arise as early as 7 weeks of GA. Detection of a single yolk sac with two embryos in very early pregnancy or the appearance of separating membranes at any time during the pregnancy should raise suspicion, as all conjoined twins are monochorionic and monoamniotic. Advanced techniques such as first-trimester transvaginal ultrasonography, coupled with color Doppler and 3D ultrasound, enable early diagnosis and prognosis determination as early as 10 weeks of GA. Early diagnosis provides parents with the choice to either continue or terminate the pregnancy [19]. Nevertheless, pregnancy termination may not be permissible in some regions due to legal, cultural, or religious considerations.
The use of 3D virtual and printed models has revolutionized preoperative planning for separating conjoined twins. This allows for a deeper understanding of complicated anatomy using 3D models, colors, and detailed textures. These 3D models facilitate in-depth discussions among medical teams, improving the understanding of surgeons and enabling practice sessions and strategic planning [20]. Additionally, virtual reality (VR) developed on 3D models from CT and MRI scans provides surgeons with a simulation of the surgical environment [21]. It also enables collaboration among surgeons from different institutions. VR has also been proven to be beneficial in planning successful separations [22].
Numerous studies have reported high mortality rates among conjoined twins. A previous study by Willoobee et al. [23] reported a mortality rate as high as 62 %, depending on the site of attachment, gestational age, sex, and birth weight [21]. Additionally, Bansal et al. [6] documented that parasitic conjoined twins who underwent early separation had over 50 % death rates. In contrast, a systematic review by Mathur et al. [11] revealed that heteropagus twins had a relatively low mortality rate of 10 %. Mathur et al. [11] found that postoperative mortality had declined over the prior 10-year period due to the more advanced preoperative planning. Thus, early diagnosis, proper preoperative planning, and careful postoperative monitoring are crucial to minimize mortality in heteropagus conjoined twins.
4. Conclusion
Early separation of parasitic conjoined twins is recommended in cases with one stillborn or deceased twin, as it improves survival chances for the autosite. Delayed separation is advised for cases with two viable twins, allowing for organ maturation and reducing intraoperative complications.
CRediT authorship contribution statement
Ahmad Yani: Writing – review & editing, Supervision, Methodology, Investigation, Data curation, Conceptualization. Wulan Ayudyasari: Writing – review & editing, Supervision. Kshetra Rinaldhy: Writing – review & editing, Validation. Muhamad Luthfi Prasetyo: Writing – original draft, Investigation, Data curation. Nafissa Amanda Safinati Yani: Writing – original draft, Data curation.
, Wulan Ayudyasari, Kshetra Rinaldhy, Muhamad Luthfi Prasetyo, Nafissa Amanda Safinati Yani,
Early separation of parasitic conjoined twins at a tertiary care hospital: A case report,
Journal of Pediatric Surgery Case Reports,
Volume 114,
2025,
102945,
ISSN 2213-5766,
https://doi.org/10.1016/j.epsc.2024.102945.
(https://www.sciencedirect.com/science/article/pii/S2213576624001738)