To study the clinical management and perinatal outcomes of monochorionic monoamniotic (MCMA) twin pregnancy.

A retrospective study was performed on the management and perinatal outcomes of 44 cases of MCMA twin pregnancy in Department of Gynecology and Obsterics, West China Second University Hospital, Sichuan University between January 2011 and December 2016.

The incidence of MCMA twin pregnancy in this study was 0.07% (44/61 607). The research results of the 44 cases of MCMA twin pregnancy were as follows. ①Two cases were diagnosed as MCMA twin pregnancy until delivery. Prenatal diagnosis of MCMA twin pregnancy was made in 42 cases, from 8^{+ 3} to 33^{+ 1} gestational weeks. ②The pregnancy outcomes were as follows. Spontaneous abortion occurred in 2 cases and 13 cases were performed induced labour due to fetal demises or fetal congenital malformation. Ten cases were with only one fetus born alive, and their birth gestational ages were 31-39^{+ 5} gestational weeks. And 19 cases were with two fetuses born alive, and their birth gestational ages were 30-36^{+ 1} gestational weeks. ③Among the 88 fetuses born by 44 cases of MCMA twin pregnant women, the incidence of fetal congenital malformation was 19.3% (17/88). And 2 pairs (4 cases) were conjoined twins, 6 cases were acardiac monstrosity, 1 case was congenital heart disease, and 6 cases were other fetal congenital malformations. ④Fetal deaths occurred in 19.7% (14/71) of non-malformed fetuses. A total of 46 cases of neonates were born alive, and the average birth weight was (1 962.6±474.6) g .There were 2 neonatal deaths in 46 liveborn neonates and the neonatal mortality was 4.3% (2/46). The liveborn neonates are being followed up and they are in good health until now. ⑤After delivery, diagnosis of MCMA twin pregnancy was confirmed by placenta examination.

MCMA twins are associated with high antenatal and perinatal mortality rates. Early diagnosis, regular antenatal examination, close fetal surveillance and concerning the appropriate timing of delivery are all critical. Strengthening the clinical management of MCMA twin pregnancy is helpful to improve the pregnancy outcomes.