Pulmonary stenosis and reactive right ventricular hypertrophy in the recipient fetus as a consequence of twin‐to‐twin transfusion

Abstract

The present study describes an association between adverse outcome in the twin-to-twin transfusion syndrome (TTTS) and pulmonary stenosis or reactive right ventricular hypertrophy. Six discordant monozygotic twin pregnancies with TTTS are described. Ventricular hypertrophy and atrioventricular valvular regurgitation occurred in all the recipient twins with pulmonary valvular stenosis in three cases and infundibular stenosis in one case. The recipient twin in one pair and both twins in another pregnancy died as a consequence of immaturity but the remaining twins all survived. Surgical intervention was required in one baby for valvular pulmonary stenosis. Our observations suggest that elevated blood pressure in the transfusion recipient may play an important role in pathogenesis. We hypothesise that both pulmonary stenosis and right chamber hypertrophy are secondary to hemodynamic changes. Although we have found valvular pulmonary stenosis in three recipients and infundibular stenosis in only one, this (obstruction to outflow) could be due to right chamber hypertrophy.

Twin-to-Twin Transfusion Syndrome: From Placental Anastomoses to Long-Term Neurodevelopmental Outcome

“…Congenital heart disease occurs 12 times more frequently in monochorionic twins with chronic TTTS than in the general population and is found mainly in recipient twins [13]. Reported cardiovascular morbidity can be transient, progressive and sometimes persists beyond the neonatal period and includes fetal hypertension [78,152], hypertrophic cardiomyopathy [12,13,153], tricuspid regurgitation [154], left chamber myocardial infarction [155], pulmonary artery calcification [156] and right ventricular outflow tract obstruction [12,157,158].…”

Fetal cardiac output in monochorionic twins

“…Monochorionic twins without TTTS also show an increased frequency (2.3%) of cardiac disease7. Cardiac pathology most frequently diagnosed includes cardiomegaly, biventricular hypertrophy, tricuspid regurgitation and right ventricular outflow tract obstruction8, 10–20. The mechanisms behind this increased rate of cardiac disease in monochorionic twins both with and without TTTS remain obscure.…”

Aortic and pulmonary artery calcification

“…The various substances released from placenta such as renin, troponin, and endothelin are also responsible for the cardiac dysfunction! [13]…”

“…Cardiac findings in this condition are varied and may include ventricular hypertrophy, pulmonary stenosis, tricuspid regurgitation, congestive cardiac failure, left ventricle hypoplasia with hypokinesia, and subaortic obstruction seen in the recipient twin. [1234]…”