Clinical characteristics and outcomes of monochorionic monoamniotic twin pregnancy

Objective: To investigate the clinical characteristics and outcomes of monochorionic monoamniotic (MCMA) twin pregnancy. Methods: The clinical data of 60 MCMA twin pregnant women who were terminated in Peking University Third Hospital from January 2011 to December 2019 were collected, and the general clinical data, prenatal examination and pregnancy outcomes were analyzed retrospectively. Results: The age of 60 MCMA twin pregnant women was (31.0±4.1) years old, among which 44 cases were primiparas (73%, 44/60) and 16 cases were multiparas (27%, 16/60). Fifty-eight cases were diagnosed as MCMA twin pregnancy prenatally and were confirmed after delivery. Median ultrasonic diagnosis of gestational age was 12 weeks (range: 8-30 weeks). In the 60 MCMA twin pregnancies, 6 cases were conjoined twins, 5 cases were complicated with twin reversed arterial perfusion sequence (TRAPS), and 10 cases were diagnosed as other fetal malformation by prenatal ultrasound examination. Among the 60 MCMA twin pregnant women, 19 cases had spontaneous abortion or induced abortion due to fetal malformation, fetal death or other reasons within 28 weeks of pregnancy, 41 cases entered the perinatal period, a total of 70 newborns survived. The main cause of perinatal fetal or neonatal death was fetal dysplasia. Conclusions: There is a high incidence of fetal abnormality and perinatal mortality in MCMA twin pregnancy. Accurate early diagnosis, enhanced management and monitoring during pregnancy, and individualized treatment are the keys to improve MCMA twin pregnancy outcomes.