Wenstrom K D, Tessen J A, Zlatnik F J, Sipes S L
Department of Obstetrics and Gynecology, University of Iowa College of Medicine, Iowa City.
Obstet Gynecol. 1992 Aug;80(2):257-61.
The purpose of this study was to determine the frequency, distribution, and most likely etiology of hematologic and weight discordance in pathologically proven monochorionic twins, and to use this information to reevaluate the neonatally derived definition of the twin-twin transfusion syndrome.
We reviewed our experience with 97 pathologically proven monochorionic twin pregnancies. The frequency and distribution of weight and hemoglobin-hematocrit (hb-hct) discordance were determined for all twin pairs. Factors that may have contributed to the discordance were identified, and theoretical mechanisms were proposed.
All combinations of weight and hb-hct discordance were observed. Thirty-four twin pairs (35%) were discordant for weight. In half of these (17 of 34), the hb and hct were concordant. In 18% (six of 34), the smaller twin had the higher hb-hct, and in 32% (11 of 34), the smaller twin had the lower hb-hct. Twenty-three of 63 size-concordant pairs (36%) were discordant for hb-hct. Ten infants were infected at birth, eight had malformations, and 25 likely suffered an acute transfusion event.
Any combination of weight and hb-hct discordance can occur in monochorionic twins. Acute and chronic twin-twin transfusion, uteroplacental insufficiency, infection, malformations, or other factors may have accounted for the discordance observed. Thorough antenatal evaluation with invasive testing and marker studies (to identify a physiologically unbalanced placental anastomosis) may be necessary to establish an accurate diagnosis. We conclude that weight and/or hb-hct discordance is relatively common in monochorionic twins and in itself is not sufficient to diagnose twin-twin transfusion.
本研究旨在确定经病理证实的单绒毛膜双胎中血液学和体重不一致的频率、分布及最可能的病因，并利用这些信息重新评估新生儿期得出的双胎输血综合征的定义。
我们回顾了97例经病理证实的单绒毛膜双胎妊娠的经验。确定了所有双胎对体重和血红蛋白 - 血细胞比容（hb - hct）不一致的频率和分布。识别了可能导致不一致的因素，并提出了理论机制。
观察到体重和hb - hct不一致的所有组合。34对双胎（35%）体重不一致。其中一半（34对中的17对）hb和hct一致。18%（34对中的6对）较小的双胎hb - hct较高，32%（34对中的11对）较小的双胎hb - hct较低。63对大小一致的双胎中有23对（36%）hb - hct不一致。10例婴儿出生时感染，8例有畸形，25例可能发生了急性输血事件。
单绒毛膜双胎中体重和hb - hct不一致的任何组合都可能出现。急性和慢性双胎输血、子宫胎盘功能不全、感染、畸形或其他因素可能导致了观察到的不一致。可能需要通过侵入性检查和标志物研究进行全面的产前评估（以识别生理上不平衡的胎盘吻合）来建立准确的诊断。我们得出结论，体重和/或hb - hct不一致在单绒毛膜双胎中相对常见，其本身不足以诊断双胎输血。
