Prenatal ultrasound diagnosis of conjoined twins and literatures review

Abstract

Objective To investigate clinical values of prenatal ultrasound diagnosis of conjoined twins. Methods On June 11, 2016 and July 29, 2017, two pairs of twins (twins 1, 2) who were diagnosed as conjoined twins in Zhongnan Hospital of Wuhan University were selected as research subjects. The clinical case data of 2 pairs of conjoined twins with fetal malformations were analyzed by retrospective method including the pregnant mother′s conditions (pregnancy history, personal and family disease history, and so on), prenatal ultrasonic manifestations, prenatal ultrasound diagnosis results, and examination results of the general specimen appearance of the twins after induction. At the same time, research literatures of conjoined twins were reviewed. Before the termination of pregnancy, all the pregnant mothers and her family signed the clinical informed consent forms. This study met the requirements of the World Medical Association Declaration of Helsinki revised in 2013. Results The clinical case data analysis results of twins 1 and 2, and their pregnant mothers were as follows. ①The pregnant mother of twins 1 was 32 years old without special personal and family disease history or adverse environmental exposure history, and her prenatal abdominal ultrasound results showed that the twin-fetal chests and abdomens were connected in the uterine cavity and a wide liquid dark area could be found in twin necks, equal echo light group with 1.4 cm × 1.0 cm and 1.3 cm × 1.1 cm also could be found in the front of twin abdomens which were suspected as abdominal organs. Twins 1 were diagnosed as live twin fetuses in the second pregnancy trimester with fetal abnormality (conjoined twins, lymphatic cysts). ② The pregnant mother of twins 2 was 27 years old without special personal and family disease history or adverse environmental exposure history, and her abdominal ultrasound results showed that the chest and abdomen of twins 2 were close to each other in the uterine cavity and could not be separated while fetal movements, heart structures of twins 2 were showed unclear, and multiple upper and lower limbs echoes could be found, and the liquid anechoic area could be found under the periderms. Twins 2 were diagnosed as live conjoined twins in the second pregnancy trimester, thickening of nuchal translucency (NT) of fetuses and fetal edema. ③Twins 1 and 2 all were induced after the prenatal ultrasound diagnosis of conjoined twins. The appearances of the gross specimens after induction of labor of 2 pairs of twins were basically the same as those of appeaiances by prenatal ultrasound examinations. Conclusions Conjoined twins are rare high-risk pregnancies. Early detection and early diagnosis of conjoined twins by prenatal ultrasound examination are beneficial to the timely treatment of conjoined twins, and can reduce the occurrence of birth defects. Key words: Twins, conjoined; Congenital abnormalities; Ultrasonography, prenatal; Prenatal diagnosis; Fetus