Cardiac time intervals and myocardial performance index for prediction of twin-twin transfusion syndrome

Evaluation of the efficacy of intrauterine treatments of twin-to-twin transfusion syndrome using myocardial performance index

Background

Prognosis of twin-to-twin transfusion syndrome (TTTS) varies depending on the Quintero stage and fetal cardiac function. The purpose of our study was to evaluate fetal cardiac function before and after different intrauterine treatments of TTTS through myocardial performance index (MPI).

Methods

In this retrospective study, data were collected from August 2016 to December 2022. Totals of 68 cases of TTTS and 68 monochorionic diamniotic (MCDA) twins without TTTS were included. MPI was collected and compared between TTTS and MCDA twins without TTTS before intrauterine treatments. TTTS cases were divided into 3 groups according to different intrauterine treatments: (I) amnioreduction (34 cases), (II) fetoscopic laser photocoagulation (FLPC; 20 cases), and (III) selective reduction (14 cases). The MPI of the left ventricle (LV) and right ventricle (RV) in each surviving fetus were measured 48 hours before and after treatments by pulse Doppler ultrasound. One-way analysis of variance (ANOVA) was employed to assess whether there were statistical differences in LV-MPI and RV-MPI among the donors, recipients, and the control group. Paired t-test analysis was used to compare whether there were differences in MPI before and after intrauterine treatments.

Results

The MPIs of the LV and RV in the recipients were significantly higher than those in the MCDA twins without TTTS (P<0.05). After the amnioreduction treatment of TTTS, no significant differences were observed in the MPI of either the LV or the RV before and after treatment. At 48 hours after FLPC treatment, the value of the LV-MPI in donors was 0.25±0.08, and the value of the RV-MPI in recipients was 0.58±0.17. Both of them were significantly lower than those before the treatment (P<0.05). In the selective reduction group, the value of the RV-MPI in surviving recipients significantly decreased compared to that before treatment (P<0.05).

Conclusions

MPI is an effective indicator to evaluate fetal cardiac function of TTTS and assess the efficacy of intrauterine treatments of TTTS.

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

OBJECTIVES

This 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).

METHODS

Adhering 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.

RESULTS

In 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.

CONCLUSIONS

This 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.