Groene Sophie G, Tollenaar Lisanne S A, van der Meeren Lotte E, Slaghekke Femke, Verweij E Joanne, Hooper Stuart B, Te Pas Arjan B, Lopriore Enrico
Neonatology, Department of Pediatrics, Leiden University Medical Center, Leiden, the Netherlands.
Molecular Epidemiology, Department of Biomedical Data Sciences, Leiden University Medical Center, Leiden, the Netherlands.
Twin Res Hum Genet. 2021 Oct;24(5):281-284. doi: 10.1017/thg.2021.46. Epub 2021 Dec 9.
We report a case of a monochorionic diamniotic twin with an uncomplicated pregnancy, but with an unexpected large intertwin hemoglobin (Hb) difference at birth. Twin 1 was delivered vaginally and had an uneventful neonatal course. The umbilical cord of Twin 1 was clamped approximately 5 min after birth. After the birth of Twin 1, Twin 2 developed severe bradycardia and showed limited cardiac output on ultrasound, for which an emergency cesarean section was performed. A full blood count revealed an Hb of 20.1 g/dL for Twin 1 and 10.2 g/dL for Twin 2 (intertwin difference 9.9 g/dL). Reticulocyte counts were similar, 40‰ and 38‰, respectively. Placental examination revealed 10 vascular anastomoses, including one arterio-arterial anastomosis with a diameter of 1.4 mm. Additionally, a large chorangioma was present on the placental surface of Twin 2. There was no color difference on the maternal side of the placenta. Based on the reticulocyte count ratio and the placental characteristics, twin anemia polycythemia sequence was ruled out as the cause of the large intertwin Hb difference. In this report, we discuss the various potential causes that could explain the large intertwin Hb difference including the role of delayed cord clamping in Twin 1, and the role of a large chorangioma, which may have attracted blood from the fetal circulation of Twin 2.
我们报告一例单绒毛膜双羊膜囊双胎妊娠，孕期无并发症，但出生时双胎间血红蛋白（Hb）差异意外增大。双胎1经阴道分娩，新生儿期过程顺利。双胎1出生后约5分钟钳夹脐带。双胎1出生后，双胎2出现严重心动过缓，超声显示心输出量有限，因此进行了急诊剖宫产。血常规显示双胎1的Hb为20.1 g/dL，双胎2为10.2 g/dL（双胎间差异9.9 g/dL）。网织红细胞计数相似，分别为40‰和38‰。胎盘检查发现10处血管吻合，包括1处直径为1.4 mm的动脉-动脉吻合。此外，双胎2的胎盘表面有一个大的绒毛膜血管瘤。胎盘母体侧无颜色差异。根据网织红细胞计数比例和胎盘特征，排除双胎贫血-红细胞增多序列作为双胎间Hb差异大的原因。在本报告中，我们讨论了各种可能解释双胎间Hb差异大的潜在原因，包括双胎1延迟钳夹脐带的作用，以及大的绒毛膜血管瘤可能从双胎2的胎儿循环中吸引血液的作用。
