Antenatal imaging diagnosis of thoraco-omphalopagus conjoined twins

Abstract

Conjoined twins occur in an estimated one in every 200,000 live births. The etiology remains largely speculative, with genetic and environmental factors being considered. The thoraco-omphalopagus type accounts for approximately 40% of cases, making it a focal point for clinical and radiological research. Radiological imaging plays a pivotal role in delineating anatomical details, offering insights into the feasibility of surgical interventions and informing parental counselling regarding prognosis and management options. We present a case of thoracoomphalogus conjoined twins diagnosed during the third trimester of pregnancy in a 19-year-old woman. The detailed radiological assessment using ultra-sound and MRI provided crucial information on organ sharing and vascular anatomy, which is critical for management strategies. This case underscores the critical role of prenatal imaging in detecting complex congenital anomalies, facilitating informed decision-making by healthcare providers and families.

Keywords: Antenatal diagnosis; Conjoined twins; MRI; Prognosis; Ultrasound.

Fig. 1

Obstetric ultrasound images from the third trimester showcasing the primary diagnostic findings of a thoraco-omphalopagus case: (A) no cranial attachment (B) merged hearts (C) One abdominal cavity with adjacent livers (D) One digestive tract.

Fig. 2

Foetal MRI (A) coronal section showing the thoraco-omphalopagus configuration of the conjoined twins; in addition to multiple axial cross sections T2 sequences at the level of the heart (B) dysmorphic unique heart, (C) 2 adjacent livers with apparent two vascular pedicles and 2 gallbladders (D) common intestinal tract.

Fig. 3

Postnatal radiograph demonstrating the twins’ attachment from the lower chest to the upper abdomen, extending up to the umbilicus.

Fig. 4

Photograph of the fetuses post-Cesarean section showing 2 thoraco-omphalopagus female twins attached from the thorax to the umbilicus, with one of the fetuses exhibiting facial dysmorphism and macrocrania.