探讨单绒毛膜双羊膜囊(MCDA)三胎妊娠的围生期管理及其围生结局。

采用回顾性分析方法，收集2012年1月至2017年9月于四川大学华西第二医院产科分娩的4例MCDA三胎妊娠孕妇的一般临床资料，包括孕妇年龄、产妇类型、受孕情况、产前检查情况，并收集其妊娠结局，包括分娩方式、围生儿结局及围生儿死亡率。同时，于4例MCDA三胎妊娠孕妇分娩后，进行胎盘及脐带检查，以进一步明确MCDA诊断及脐带缠绕情况。

本组4例MCDA三胎妊娠孕妇的年龄为20～28岁，均为自然受孕的初产妇。其中，在本院接受定期产前检查的孕妇为2例(No.1、No.2孕妇)，MCDA三胎诊断时，其孕龄分别为13^＋4、18^＋5孕周，并且分别于32^＋3、32^＋5孕周时采取剖宫产术分别分娩3例女活婴，共计6例女活婴，随访结果显示这6例新生儿均生长发育良好。另外2例孕妇(No.3、No.4孕妇)均因未足月胎膜早破(PPROM)，分别于孕龄为28、21^＋3孕周时急诊转入本院。这2例孕妇孕期均未接受正规产前检查，均于产时确诊为MCDA三胎妊娠。其中，No.3孕妇因母体因素于孕龄为28^＋3孕周时采取剖宫产术终止妊娠，娩出3例男活胎，这3例新生儿分别于出生后6 d(1例)、23 d(2例)死亡。No.4孕妇于孕龄为21^＋3孕周时发生PPROM，1例胎儿入院前流产死亡(单独羊膜囊内胎儿)，入院后另外2例胎儿随即流产死亡(1例合并唇腭裂、1例为无心畸胎)。本组MCDA三胎妊娠孕妇的围生儿死亡率为11.1%(1/9)。对本组4例MCDA三胎妊娠孕妇进行产后胎盘及脐带检查的结果均证实MCDA三胎的诊断，而且No.1、2、3孕妇三胎中处于同一羊膜囊内的双胎，均存在脐带缠绕、打结。

MCDA三胎妊娠十分罕见，为取得较好的围生结局，对其围生期管理宜早期诊断、定期规律产前检查、严密监护，完善产前保健，并与孕妇本人及其家属进行充分的病情沟通。

To study perinatal management and outcomes for monochorionic diamniotic (MCDA) triplet pregnancies.

A retrospective study was conducted to evaluate perinatal management and outcomes of MCDA triplet pregnancies in West China Second University Hospital, Sichuan University from January 2012 to September 2017 including general clinical data, such as maternal age, primipara or multipara, pregnancy condition and prenatal examination, and pregnancy outcomes, such as delivery mode and perinatal outcomes and mortality. Meanwhile, placental and umbilical cord examination were given after delivery to identify the diagnosis of MCDA and umbilical cord entanglement.

A total of 4 cases of MCDA triplet pregnancies included in our study all were primiparae and spontaneously conceived with age between 20 to 28 years. Two cases (No.1 and No.2 pregnant women) had regular prenatal examinations in our hospital and were diagnosed as MCDA triplet pregnancies at 13^{+ 4,} 18^{+ 5} gestational weeks, respectively. They had caesarean section at 32^{+ 3,} 32^{+ 5} gestational weeks and gave birth to six health and survival female babies. And the following-up results showed that all the 6 neonates grew well. And No.3 and No.4 pregnant women were transferred to our hospital due to preterm premature rupture of membranes (PPROM) at 28, 21^{+ 3} gestational weeks, respectively. Both of them did not have regular prenatal examinations. The diagnosis of MCDA triplet pregnancies were made during childbirth. No.3 pregnant woman had cesarean section due to maternal factor at 28^{+ 3} gestational weeks and gave birth to three male live babies. But these three newborns were died in 6 days after birth (1 newborn), 23 days after birth (2 newborns). No.4 pregnant woman gave birth to three dead fetus at 21^{+ 3} gestational weeks for inevitable abortion, and one still fetus (in single amniotic cyst) occurred abortion before admission in our hospital, and two fetuses were complicated with malformations (one fetus had cleft lip and palate, the other one were acardiac). The perinatal mortality of MCDA triplet pregnancies in this study was 11.1% (1/9). The placental and umbilical cord examination of 4 pregnant women were given after delivery, and all confirmed the prenatal diagnosis of MCDA triple pregnancies. The twin fetuses in single amniotic cyst of No.1, No.2, and No.3 pregnant women all had umbilical cord entanglement.

MCDA triplet pregnancies are very rare. To get a better perinatal outcome of MCDA triplet pregnancies, we recommend early diagnosis, regular prenatal examinations, close prenatal monitoring to improve prenatal care, and communication with patients and their families.