不同绒毛膜性双胎妊娠的早产原因及其影响因素

Clinical features and influencing factors for prematurity in both dichorionic and monochorionic diamniotic twins

目的探讨不同绒毛膜性双胎妊娠不同孕周早产的原因及其危险因素。方法2012年9月至2015年3月在中山大学附属第一医院活产分娩的363例双胎妊娠孕妇中，290例发生早产者纳入分析，其中双绒毛膜双羊膜囊（dichorionic diamniotic，DCDA）双胎219例，单绒毛膜双羊膜囊（monochorionic diamniotic，MCDA）双胎71例。回顾病历资料，按早产孕周分为28～31^＋6、32～33^＋6和34～36周^＋6组。比较不同孕周早产和不同绒毛膜性双胎的临床特点、早产原因，并分析其危险因素。采用方差分析、χ^2检验及多因素Logistic回归分析进行统计学处理。结果双胎妊娠早产率为79．9％（290／363）。DCDA双胎的早产率为76．3％（219／287），低于MCDA双胎[93．4％（71／76）]（χ^2=10．955，P=O．001）。DCDA双胎早产原因前3位分别是≥36孕周（33．8％，74／219）、早产临产（30．6％，67／219）和未足月胎膜早破（8．7％，19／219）。MCDA双胎早产原因前3位是早产临产（31．0％，22／71）、选择性宫内生长受限（21．1％，15／71）和≥36孕周（19．7％，14／71）。将单因素分析中差异有统计学意义的变量（绒毛膜性、子痫前期、未足月胎膜早破和早产临产）纳入Logistic回归分析，结果发现：双胎妊娠28～31周^＋6早产的危险因素是未足月胎膜早破（OR=2．390，95％CI：1．006～5．872，P=0．043）。双胎妊娠32～33周^＋6早产的危险因素是绒毛膜性为MCDA（OR=2．758，95％CI：1．243～6．118，P=0．013）、子痫前期（OR=12．176，95％C1：4．685～31．642，P=0．000）、未足月胎膜早破（OR=5．348，95％CI：2．151～13．294，P=O．000）和早产临产（OR=3．274，95％C／：1．453～7．375，P=0．004）。双胎妊娠34～36周^＋6早产的危险因素是绒毛膜性为MCDA（OR=3．666，95％CI：1．364～9．585，P=0．010）和子痫前期（OR=8．086，95％CI：1．044～62．617，P=0．045）。结论MCDA双胎早产率高于DCDA双胎，且二者早产的原因不尽相同．双胎杆娠不同孕周早产的危险因素也不尽相同．

Objective To investigate the risk factors of preterm birth, as well as the clinical characteristics in dichorionic diamniotic （DCDA） twins and monochorionic diamniotic （MCDA） twins. Methods A retrospective study was conducted on 290 premature cases out of 363 twin pregnancies who delivered alive babies in the First Affiliated Hospital, Sun Yat-sen University from September 2012 to March 2015. The selected cases, including 219 cases of DCDA and 71 cases of MCDA,were divided into three groups according to their gestational age at delivery： 28-31^＋6, 32-33^＋6 and 34-36^＋6 weeks. The clinical features, causes and risk factors were described between these three groups. Analysis of variance, Chi-square test and multi-variant Logistic regression were used for statistical analysis. Results The incidence of.premature delivery in twin pregnancies was 79.9% （290/363）, while this figure was lower in DCDA twins than in MCDA [76.3%（219/287） vs 93.4%（71/76）, χ^2=10.955, P=0.001]. The three leading causes of preterm birth in DCDA twins were gestational age ≥36 weeks （33.8%, 74/219）, preterm labor （30.6%, 67/219） and preterm premature rupture of membrane （PPROM） （8.7%, 19/219）, while in MCDA twins were preterm labor （31.0%, 22/71）, selective intrauterine growth restriction （21.1%, 15/71） and gestational age ≥36 weeks （19.7%, 14/71）. Logistic regression analysis showed that the independent risk factors of preterm birth in twins at 28-31^＋6 weeks was PPROM （OR=2.390, 95%CI： 1.006-5.872, P=0.043）, and for those twins at 32-33^＋6 weeks, the independent risk factors were MCDA （OR=2.758, 95%CI： 1.243-6.118, P=0.013）, preeclampsia （OR=12.176, 95%CI：4.685- 31.642, P=0.000）, PPROM （OR=5.348, 95%CI： 2.151-13.294, P=0.000） and preterm labor （OR=3.274, 95%CI：1.453-7.375, P=0.004）. MCDA （OR=3.666, 95%CI： 1.364-9.585, P=0.010） and preeclampsia （OR=8.086, 95%CI：1.044-62.617, P=0.045） were the risk factors in the group of 34-36^＋6 weeks. Conclusions Although preterm birth in MCDA and DCDA twins is due to different reasons, the former has a higher incidence than the latter. The risk factors of premature delivery at different gestations are also different.