Fetal Medicine Unit, Division of Developmental Sciences, St George's University of London, London SW17 0RE, UK.
Hum Reprod. 2013 Oct;28(10):2621-7. doi: 10.1093/humrep/det277. Epub 2013 Jul 11.
Is there an association between discordance in embryonic growth and fetal loss at the time of the 11-14-week scan in twin pregnancies?
Regardless of the chorionicity, crown rump length (CRL) discordance at 7(+0)-9(+6) weeks is predictive of subsequent single fetal demise in the first trimester.
Previous small studies have reported a variable association between discordance in embryonic growth and subsequent fetal loss.
STUDY DESIGN, SIZE, DURATION: Retrospective study of all twin pregnancies of known chorionicity from a large regional cohort over a 10-year period. A total of 1356 twin pregnancies (288 monochorionic and 1068 dichorionic) were included in the study.
PARTICIPANTS, SETTING, METHODS: Women presenting to the early pregnancy unit were included in the study. Logistic regression, ROC curve and Kaplan-Meier analyses were performed to evaluate the association between CRL discordance at 7(+0)-9(+6) weeks and spontaneous single fetal loss diagnosed at the 11-14-week scan. A systematic review was also performed using MEDLINE, EMBASE, Cinahl and the Cochrane Library in order to explore the relationship between early growth discordance and single fetal loss in twin pregnancies.
There were 111 (8.2%) single fetal losses diagnosed at 11-14 weeks in this cohort. At multivariate analysis, CRL discordance percentile [odds ratio (OR) 1.20; 95% confidence interval (CI), 1.12-1.63, P < 0.0001] and CRL <5th centile of at least one twin (OR, 2.21; 95% CI 1.23-4.24, P = 0.023), but not chorionicity (P = 0.486) or maternal age (P = 0.283) was independently associated with the loss of one fetus at the 11-14-week scan. The predictive accuracy of CRL discordance for single fetal loss was high (AUC = 0.93; 95% CI = 0.91-0.94). A significant association was found between the increase in the degree of embryonic discordance and the likelihood of early fetal loss (P < 0.0001).
LIMITATIONS, REASONS FOR CAUTION: Only a high-risk population was analysed. Therefore, the patients studied were not a representative sample from the population of women pregnant with twins.
Twin pregnancies, in particular those resulting from assisted conception, are scanned frequently, particularly during the early stages of pregnancy. The findings of this study are likely to prove important in counselling parents about the short-term outcome of the pregnancy when an embryonic discordance is present.
STUDY FUNDING/COMPETING INTEREST(S): No external funding was sought for this study. None of the authors has any conflicts of interest to declare.
双胞胎妊娠 11-14 周扫描时胚胎生长不一致与胎儿丢失之间是否存在关联？
无论绒毛膜性如何，7（+0）-9（+6）周时的头臀长（CRL）差异与妊娠早期随后的单一胎儿死亡有关。
以前的一些小研究报告了胚胎生长不一致与随后的胎儿丢失之间存在可变的关联。
研究设计、大小和持续时间：对 10 年内大型区域队列中已知绒毛膜性的所有双胞胎妊娠进行回顾性研究。共有 1356 例双胞胎妊娠（288 例单绒毛膜性和 1068 例双绒毛膜性）纳入研究。
参与者、设置和方法：在早期妊娠单位就诊的妇女被纳入研究。采用逻辑回归、ROC 曲线和 Kaplan-Meier 分析评估 7（+0）-9（+6）周时 CRL 差异与 11-14 周扫描时诊断的自发性单一胎儿丢失之间的关系。还使用 MEDLINE、EMBASE、Cinahl 和 Cochrane 图书馆进行了系统评价，以探讨双胞胎妊娠中早期生长不一致与单一胎儿丢失之间的关系。
在该队列中，有 111 例（8.2%）在 11-14 周时诊断为单一胎儿丢失。多变量分析显示，CRL 差异百分位数[比值比（OR）1.20；95%置信区间（CI）1.12-1.63，P < 0.0001]和 CRL <第 5 百分位数的至少一个胎儿（OR，2.21；95%CI 1.23-4.24，P = 0.023），但不是绒毛膜性（P = 0.486）或母亲年龄（P = 0.283）与 11-14 周扫描时一个胎儿的丢失独立相关。CRL 差异对单一胎儿丢失的预测准确性较高（AUC = 0.93；95%CI = 0.91-0.94）。胚胎不一致程度的增加与早期胎儿丢失的可能性之间存在显著关联（P < 0.0001）。
局限性、谨慎的原因：仅分析了高危人群。因此，所研究的患者并非来自怀双胞胎的孕妇的代表性样本。
双胞胎妊娠，特别是通过辅助受孕获得的妊娠，经常进行扫描，尤其是在妊娠早期。当存在胚胎不一致时，本研究的发现可能在为父母提供有关妊娠短期结局的咨询方面证明非常重要。
研究资金/利益冲突：本研究未寻求外部资金。作者均无任何利益冲突。
