Department of Obstetrics and Gynecology, Medical University of South Carolina, Charleston, SC.
Department of Obstetrics and Gynecology, Southern Illinois University School of Medicine, Springfield, IL.
Am J Obstet Gynecol. 2014 Jun;210(6):578.e1-9. doi: 10.1016/j.ajog.2014.03.003. Epub 2014 Mar 5.
The purpose of this study was to determine the prospective risk of intrauterine fetal death (IUFD) at ≥34 weeks' gestation for monochorionic and dichorionic twins receiving intensive antenatal fetal surveillance. The secondary objective was to calculate the incidence of prematurity-related neonatal morbidity/mortality rates that have been stratified by gestational week and chorionicity.
A retrospective cohort study of all twins at ≥34 weeks' gestation who were delivered at the Medical University of South Carolina (1987-2010) was performed. Twins were cared for in a longstanding Twin Clinic with standardized treatment and surveillance protocols and supervised by a consistent Maternal-Fetal Medicine specialist. Gestational age-specific fetal/neonatal mortality rates and composite neonatal morbidity rates were compared by chorionicity. A generalized linear mixed model was used to identify variables that were associated with increased composite neonatal morbidity.
Among 768 twin gestations (601 dichorionic and 167 monochorionic), only 1 dichorionic IUFD occurred. The prospective risk of IUFD at ≥34 weeks' gestation was 0.17% for dichorionic twins and 0% for monochorionic twins. Composite neonatal morbidity decreased with each gestational week (P < .0001). Morbidity was increased by white race, gestational diabetes mellitus, and elective indication for delivery. The nadir of composite neonatal morbidity occurred at 36/0-36/6 weeks' gestation for monochorionic twins and 37/0-37/6 weeks' gestation for dichorionic twins.
Our data do not support concern for an increased risk of stillbirth in uncomplicated intensively monitored monochorionic twins at ≥34 weeks' gestation. However, our data do show significantly increased rates of neonatal morbidity in late preterm monochorionic twins that cannot be justified by a corresponding reduction in the risk of stillbirth. We believe that our data support delivery of uncomplicated monochorionic twins at 37 weeks' gestation.
本研究旨在确定接受强化产前胎儿监测的单绒毛膜和双绒毛膜双胞胎在≥34 孕周时发生宫内胎儿死亡（IUFD）的前瞻性风险。次要目的是按孕周和绒毛膜性分层计算与早产相关的新生儿发病率/死亡率。
对 1987 年至 2010 年在南卡罗来纳医科大学分娩的所有≥34 孕周的双胞胎进行回顾性队列研究。双胞胎在一个历史悠久的双胞胎诊所接受治疗，有标准化的治疗和监测方案，并由一位固定的母胎医学专家监督。按绒毛膜性比较特定孕周的胎儿/新生儿死亡率和复合新生儿发病率。使用广义线性混合模型确定与复合新生儿发病率增加相关的变量。
在 768 例双胎妊娠（601 例双绒毛膜和 167 例单绒毛膜）中，仅 1 例双绒毛膜 IUFD 发生。≥34 孕周时双绒毛膜双胞胎的 IUFD 前瞻性风险为 0.17%，单绒毛膜双胞胎为 0%。复合新生儿发病率随孕周增加而降低（P<0.0001）。发病率增加与白种人、妊娠期糖尿病和选择性分娩指征有关。单绒毛膜双胞胎复合新生儿发病率的最低点出现在 36/0-36/6 孕周，双绒毛膜双胞胎出现在 37/0-37/6 孕周。
我们的数据不支持对≥34 孕周时未合并症的强化监测的单绒毛膜双胞胎死胎风险增加的担忧。然而，我们的数据确实表明，晚期早产儿单绒毛膜双胞胎的新生儿发病率显著增加，而死胎风险的相应降低并不能证明这一点。我们认为，我们的数据支持在 37 孕周时分娩未合并症的单绒毛膜双胞胎。
