Cardiac adaptation and malformation in twin–twin transfusion syndrome and selective fetal growth restriction: A systematic review

Abstract

ObjectivesThis systematic review explores cardiac adaptation in monochorionic (MC) twins with twin–twin transfusion syndrome (TTTS) or selective fetal growth restriction (sFGR) and assesses the risk of congenital heart defects (CHDs).MethodsAdhering to PRISMA guidelines, 63 studies were reviewed (49 on cardiac adaptation, 13 on CHD, one on both). A narrative synthesis of cardiac adaptation patterns was performed. Additionally, a meta‐analysis compared the livebirth prevalence of CHD in TTTS and sFGR against uncomplicated MC twins.ResultsIn TTTS recipients, cardiac function may be impaired for diastolic, systolic, as well as global functions, while in donors, cardiac function is generally preserved. In sFGR, large twins may show hypertrophic cardiomyopathy, and small twins may show impaired systolic function. Co‐occurrence of TTTS and sFGR magnifies cardiac impact but is often underreported. Meta‐analysis for CHD prevalence revealed a relative risk ratio of 3.5 (95% CI: 2.5–4.9) for TTTS and 2.2 (95%CI: 1.3–3.5) for sFGR compared with uncomplicated MC twins.ConclusionsThis study highlights the well‐documented cardiac adaptation in TTTS, contrasting with limited understanding in sFGR. Elevated CHD risks were observed in both conditions. Enhanced cardiovascular surveillance is warranted in complicated MC twin pregnancies. Future research should explore cardiac adaptation in sFGR and its long‐term consequences.

The bright future of fetal cardiology

“…The work of Noll et al with a systematic review of cardiac adaptation in complicated monochorionic twins explores the close relationship between altered hemodynamics and both functional and structural cardiac anomalies. 17 In monochorionic pregnancies complicated by twin transfusion syndrome and FGR, the likelihood of a structural cardiac anomaly is 3.5 and 2.2 times more likely as compared to uncomplicated monochorionic twins, respectively. This finding is not only scientifically intriguing but also has clinical implications in terms for fetal and/or postnatal cardiac evaluation.…”