The application value of prenatal ultrasound in conjoined twins.

Objective: To evaluate the application and effectiveness of prenatal ultrasound in diagnosing and managing conjoined twins.

Methods: A retrospective analysis was conducted on 20 cases of conjoined twins diagnosed at our hospital between January 2016 and December 2022. The types of conjoined twins, ultrasonographic characteristics, and associated anomalies were assessed.

Results: The gestational age at diagnosis ranged from 10 to 35 weeks, with an average of 14.21 ± 5.69 weeks. Thirteen cases were detected in the first trimester, five in the early second trimester, one at 23 + 2 weeks, and one at 35 weeks. Thoracopagus was the most common type (11 cases, 55%), followed by omphalopagus (4 cases, 20%), cephalopagus (4 cases, 20%), and parapagus dicephalus (1 case, 5%). In the first trimester, the most common abnormalities observed included increased nuchal translucency (NT), cystic hygroma, hydrops fetalis, and generalized edema. Major birth defects identified in conjoined twins were omphalocele (3 cases), congenital heart malformations (3 cases), neural tube defects (2 cases), urachal cyst (1 case), and umbilical cyst (1 case). Pregnancy was terminated in 18 cases, one case resulted in spontaneous abortion during the second trimester, and one case was delivered by cesarean section at 37 weeks, with successful separation and recovery.

Conclusion: Prenatal ultrasound is the primary diagnostic tool for conjoined twins. It effectively assesses the extent of twin fusion, provides critical information for clinical decision-making, and aids in the management of obstetric care.