Objective: To investigate the differences in amniotic fluid cardiac biomarkers and clinical features among types of right ventricular outflow tract (RVOT) abnormality in monochorionic (MC) twins.
Method: This prospective study included MC twins that underwent laser surgery. Recipient or larger twins (group A) and donor or smaller twins (group B) were assessed and divided into those with a normal right ventricular outflow tract (normal RVOT), functional pulmonary atresia (fPA), or pulmonary stenosis (PS). Amniotic fluid levels of NT-proBNP (afNT-proBNP) and cardiac troponin T (afTnT) were examined during surgery.
Results: Of 190 fetuses in group A, there were 14 RVOT abnormality cases (including 7 fPA and 7 PS). No group B fetuses showed RVOT abnormality findings. In group A, later and earlier gestational age at surgery were observed in fPA (25.1 ± 2.8 weeks) and PS groups (17.8 ± 0.9 weeks). All survived PS cases demonstrated progressive pulmonary valve obstruction, not observed in fPA groups. AfNT-proBNP were significantly higher in fPA and PS than in the normal RVOT group (p < 0.05). AfTnT was significantly higher in group A with PS than fPA and normal RVOT groups (p < 0.05).
Conclusion: Among RVOT abnormality types in group A, amniotic fluid cardiac biomarkers were differently expressed, and clinical features were also differentiated. These findings provide insight into the pathophysiological influence on RVOT in MC twins.
Clinical trial registration: This study was registered with the Japanese Clinical Trial Registry "UMIN-CTR" (http://www.umin.ac.jp/ctr/index-j.htm; trial ID numbers UMIN000024486 and 000037702).
© 2022 John Wiley & Sons Ltd.