Department of Obstetrics and Gynecology, The Chaim Sheba Medical Center, Tel HaShomer, Israel.
J Perinat Med. 2012 May 13;40(5):489-93. doi: 10.1515/jpm-2011-0250.
To examine the correlation between measurements of crown rump length (CRL), nuchal translucency (NT), and birth weight in dichorionic (DC) and monochorionic (MC) twin pregnancies.
A retrospective analysis was performed on all twin term pregnancies delivered between 2001 and 2007 at the McGill University Health Center. Data collected included maternal age, CRL and NT measurement, results of glucose challenge test, birth weight and length, gestational age at delivery, and fetal gender.
The study population comprised 792 fetuses: 94 MC/DA and 698 DC/DA. Maternal age, gestational age at delivery, birth weight, and birth length were all significantly higher for the DC group. Male fetuses had significantly higher NT and higher birth weight than female fetuses. Discordance in CRL was found to correlate with discordance in birth weight in the entire study population (P<0.0001, R=0.25), in the DC twins (P<0.0001, R=0.275), but not in MC twins (R=0.10, P=0.33). CRL discordance above the 90th percentile (>12%) predicted 14/40 pregnancies with birth weight discordance above the 90th percentile (>24%) [P<0.001, LR=4.1 (2.6-6.2)]. CRL discordance above the 95th percentile (>16%) predicted 5/21 pregnancies with birth weight discordance above the 95th percentile (>30%) [P<0.001, LR=5.5 (2.6-10.4)]. NT discordance was correlated with CRL discordance (R=0.15, P<0.0001), but not with birth weight, regardless of chorionicity or gender.
In twin pregnancies, CRL discordance in first trimester can predict discordance of more than 25% in neonatal birth weight.
探讨双绒毛膜（DC）和单绒毛膜（MC）双胎妊娠中胎儿头臀长（CRL）、颈项透明层（NT）与出生体重的相关性。
对 2001 年至 2007 年在麦吉尔大学健康中心分娩的所有足月双胎妊娠进行回顾性分析。收集的数据包括母亲年龄、CRL 和 NT 测量值、葡萄糖挑战试验结果、出生体重和长度、分娩时的孕周以及胎儿性别。
研究人群包括 792 例胎儿：94 例 MC/DA 和 698 例 DC/DA。DC 组的母亲年龄、分娩时的孕周、出生体重和出生体长均显著较高。男性胎儿的 NT 和出生体重均显著高于女性胎儿。整个研究人群（P<0.0001，R=0.25）、DC 双胞胎（P<0.0001，R=0.275）中，CRL 差异与出生体重差异相关，而 MC 双胞胎中无相关性（R=0.10，P=0.33）。CRL 差异超过第 90 百分位数（>12%）预测了 40 例中有 14 例出生体重差异超过第 90 百分位数（>24%）的妊娠（P<0.001，LR=4.1（2.6-6.2））。CRL 差异超过第 95 百分位数（>16%）预测了 21 例中有 5 例出生体重差异超过第 95 百分位数（>30%）的妊娠（P<0.001，LR=5.5（2.6-10.4））。NT 差异与 CRL 差异相关（R=0.15，P<0.0001），但与出生体重无关，与绒毛膜性或性别无关。
在双胎妊娠中，早孕期 CRL 差异可预测新生儿出生体重差异超过 25%。
