双胎发育不均衡的危险因素及妊娠结局

目的探讨双胎发育不均衡的发生率、母婴不良结局以及相关危险因素,旨在为临床上预防双胎发育不均衡、改善新生儿结局提供参考和借鉴。方法2017年1月至2018年6月,在广州医科大学附属第三医院住院分娩的孕产妇中,纳入其中的双胎妊娠孕产妇2912例及新生儿5824例为研究对象。两个胎儿出生体重相差≥20%为双胎发育不均衡组;<20%为双胎发育均衡组。根据病历及随访登记,记录孕产妇和新生儿的临床资料,比较双胎发育不均衡组与均衡组的围产结局,分析双胎发育不均衡的危险因素。统计学分析采用独立样本t检验、χ~2检验和多因素Logistic逐步回归分析。结果2912例双胎孕妇中,双胎发育不均衡发生率为3.54%(103/2912)。不均衡组的新生儿出生体重低于均衡组,住院时间、小于胎龄儿比例及最低体重出现日龄均大于均衡组(P<0.05)。多因素Logistic回归分析提示,年龄>30岁(OR=1.853)、孕周≤35周(OR=2.368)、孕次≥2次(OR=2.941)、孕前体重指数≤25 kg/m^2(OR=2.457)、合并妊娠期糖尿病(OR=3.624)、合并妊娠期高血压(OR=1.725)、单绒毛膜单羊膜囊(monochorionic monoamniotic,MCMA)双胎(OR=2.529)、双胎异性(OR=1.603)是双胎发育不均衡的影响因素(P<0.05)。双胎发育不均衡组的产妇感染、羊水过多、羊水过少、胎膜早破、早产、产后出血、胎儿生长受限、新生儿感染性肺炎、新生儿窒息、胎儿窘迫、新生儿低血糖、高胆红素血症、新生儿死亡的发生比例均高于双胎发育均衡组(P<0.05)。双胎发育不均衡的103例中,MCMA、单绒毛膜双羊膜囊(monochorionic diamniotic,MCDA)、双绒毛膜双羊膜囊(dichorionic diamnionic,DCDA)3亚组间比较,产妇感染、羊水过多、羊水过少、胎膜早破、产后出血、胎儿生长受限、新生儿窒息、新生儿低血糖的发生比例,3亚组间差异均有统计学意义,MCMA组的上述指标发生比例均高于其他2个亚组(P<0.05)。结论双胎妊娠发育不均衡增加孕妇及新生儿不良结局的发生风险;双胎发育不均衡与产妇年龄、孕周、孕次、孕前BMI、合并妊娠期糖尿病、合并妊娠期高血压、MCMA双胎、双胎异性等因素密切相关。

Risk factors and perinatal outcomes of twin pregnancies with growth discordance

Objective To explore the incidence, adverse maternal and infant outcomes and related risk factors of discordant twins, in order to provide reference for prevention of discordant twins and improvement of neonatal outcomes. Methods From January 2017 to June 2018, 2 912 cases of twin pregnant women and 5 824 cases of newborn were included among the pregnant women in the Third Hospital Affiliated to Guangzhou Medical University. They were divided into discordant group(the birth weight difference of the two newborns ≥ 20%) and normal group(the birth weight difference of the two newborns<20%). According to the medical records and follow-up registrations, the clinical data of pregnant women and newborns were recorded. The perinatal outcomes of the two groups were compared, and the risk factors of discordant twins were analyzed. Independent sample t-test, χ~2 test and stepwise Logistic regression analysis were used for statistical analysis. Results In 2 912 cases of twin pregnant women, the rate of discordant twins was 3.54%(103/2 912). The birth weight of the discordant group was lower than that in the normal group, and the length of hospitalization, the proportion of infants with small gestational age and the age of the lowest birth weight were all higher than that in the normal group(P<0.05). Multivariate logistic regression analysis showed that age > 30 years old(OR=1.853), gestational age ≤ 35 weeks(OR=2.368), gravida ≥ 2 times(OR=2.941), pre-pregnancy BMI ≤ 25 kg/m^2(OR=2.457), gestational diabetes mellitus(OR=3.624), gestational hypertension(OR=1.725), monochorionic monoamniotic(MCMA) twin(OR=2.529), and twin heterosis(OR=1.603) were the influencing factors of discordant twins(P<0.05). The incidence of maternal infection, polyhydramnios, oligohydramnios, premature rupture of membranes, premature delivery, postpartum hemorrhage, fetal growth restriction, neonatal infectious pneumonia, neonatal asphyxia, fetal distress, neonatal hypoglycemia, hyperbilirubinemia and neonatal death in the discordant group were higher than that in the normal group(P<0.05). The 103 cases with discordant twin were divided into three subgroups: MCMA, monochorionic diamniotic(MCDA) and dichorionic diamnionic(DCDA). The incidence of maternal infection, polyhydramnios, oligohydramnios, premature rupture of membranes, postpartum hemorrhage, fetal growth restriction, neonatal asphyxia and hypoglycemia were significantly different among the three subgroups. The incidences of the above indexes in the MCMA group were higher than those in the MCDA and DCDA groups(P<0.05). Conclusions Discordant twin pregnancy increases the risk of adverse outcomes of pregnant women and newborns. Discordant twin pregnancy is closely related to the factors such as maternal age, gestational weeks, gestational times, pre-pregnancy BMI, gestational diabetes, gestational hypertension, MCMA twin and twin heterosexuality.