这项研究旨在评估与有或没有脐带近端插入(PCI)的单绒毛膜羊膜(MCDA)双胞胎相关的相对胎盘特征和妊娠结局。
本队列研究包括2013年4月1日至2021年4月1日期间通过染料注射评估胎盘特征的所有完整胎盘分娩的MCDA双胞胎。病例分为PCI和非PCI组,然后比较这些组的妊娠结局和胎盘特征。
相对于非PCI组,PCI组的出生体重不一致率显着降低(7.3±7.5%vs29.9±16.8%,P<0.001),相对于非PCI组,动脉-动脉(AA)率,静脉-静脉(VV),厚AA,PCI组和厚的VV吻合术明显高于PCI组(95.5%vs67.0%,P=0.008,59.1%vs16.4,P<0.001,90.5%vs34.9%,P<0.001,54.5%vs10.5%,P<0.001)。在PCI组中观察到明显更多的吻合(7(3,11)vs6(3,15),P=0.015),它们的平均值明显大于非PCI组的12.8(6.7,21.3)mmvs11.9(3.4,24.6)mm,P=0.009)。相对于非PCI组,PCI组的胎盘区域不一致和UCI比率显着降低(23.5(15.0,51.0)%vs60.0(2.0,80.0)%,P<0.001,13.3±5.8%vs56.1±18.0%,P<0.001)。相对于非PCI组,PCI组的边缘脐带插入率较低(13.6%vs77.5%,P<0.001)。
有PCI的MCDA双胞胎的胎盘结构与没有PCI的双胞胎的胎盘结构不同,这些结果表明PCI可能表明MCDA胎儿之间胎盘区域分布更均匀。
This study was developed to evaluate the relative placental characteristics and pregnancy outcomes associated with monochorionic diamniotic (MCDA) twins with and without proximate umbilical cord insertion (PCI).
All MCDA twins delivered with complete placentas for whom placental characteristics were assessed via dye injection between April 1, 2013 and April 1, 2021 were included in the present cohort study. Cases were separated into PCI and non-PCI groups, and pregnancy outcomes and placental characteristics were then compared between these groups.
Birthweight discordance rates were significantly lower in the PCI group relative to the non-PCI group (7.3 ± 7.5% vs 29.9 ± 16.8%, P<0.001), while relative to the non-PCI group, rates of artery-artery (AA), vein-vein (VV), thick AA, and thick VV anastomoses were significantly higher in the PCI group (95.5% vs 67.0%, P = 0.008, 59.1% vs 16.4, P<0.001,90.5% vs 34.9%, P<0.001, 54.5% vs 10.5%, P<0.001). Significantly more anastomoses were observed in the PCI group (7 (3,11) vs 6 (3,15), P = 0.015), and they were significantly larger on average than those in the non-PCI group 12.8 (6.7,21.3) mm vs 11.9 (3.4, 24.6) mm, P = 0.009). Significantly lower placental territory discordance and UCI ratios were evident in the PCI group relative to the non-PCI group (23.5 (15.0,51.0) % vs 60.0 (2.0,80.0) %, P<0.001, 13.3 ± 5.8% vs 56.1 ± 18.0%, P < 0.001). Marginal cord insertion rates were lower in the PCI group relative to the non-PCI group (13.6% vs 77.5%, P < 0.001).
The placental structure of MCDA twins with PCI is distinct from that of twins without PCI, and these results suggest PCI may be indicative of the more even distribution of placental territory between MCDA fetuses.