The East Flanders Prospective Twin Survey, started in 1964, realised for the first time a population-based register of all multiple births in the Belgian Province of East Flanders. The EFPTS is characterized by the systematic examination of the placenta and the accurate determination of zygosity based on structure of fetal membranes, blood groups and DNA. For decades, it has been the only register to include chorionicity in same-sex twin pairs, an irreplaceable tool allowing almost certain diagnosis of monozygosity and the timing of the division of the zygote in monozygotic twins. With over 8000 twin pairs and ongoing recruitment the EFPTS is one of world largest twin registers. Our current focus of research is on the development of obesity, type 2 diabetes mellitus and cardiovascular diseases, cognitive development and laterality.
Marij Gielen, PhD