Acardiac twin pregnancies part III: Model simulations
Martin J C van Gemert1, Michael G Ross2, Peter G J Nikkels3
1Department of Biomedical Engineering & Physics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
Birth Defects Research. Part A, Clinical and Molecular Teratology
|September 16, 2016
Summary
Acardiac twin simulations reveal umbilical venous diameter ratios predict pump twin survival. The arterioarterial anastomosis is key, guiding interventions for acardiac twin pregnancies.
Area of Science:
- Fetal Medicine
- Reproductive Biology
- Medical Simulation
Background:
- Acardiac twins develop via passive perfusion and hypoxia-driven neovascularization.
- Pump twins face increased cardiac output demands, risking heart failure.
- Existing twin-twin transfusion syndrome models were adapted for acardiac twin pregnancies.
Purpose of the Study:
- To adapt a twin-twin transfusion syndrome model for acardiac twin pregnancies.
- To simulate pump and acardiac twin development.
- To identify early prognostic markers for pump twin survival.
Main Methods:
- An infinite acardiac placental resistance model was employed.
- Simulations determined pump twin excess cardiac output via arterioarterial (AA) and venovenous (VV) anastomoses resistance.
- Pump and acardiac development were assessed using pump/acardiac umbilical venous diameter (UVD) ratios.
Main Results:
- UVD ratios differentiated between AA-VV anastomoses causing hydropic versus non-hydropic pump twins.
- Pump twins tolerate greater acardiac perfusion later in gestation.
- AA resistance significantly exceeds both VV and acardiac resistances.
Conclusions:
- Simulations support UVD ratios as predictors of pump twin risk.
- The AA anastomosis critically influences outcomes for both twins.
- Findings may enhance prognosis and guide selective interventions in acardiac twin pregnancies.
