Performing cytogenetic studies on ascitic, amniotic and hygroma fluid. The importance of obtaining cytogenetic studies on antenatally diagnosed structural malformations is well recognized. In two cases, three fetal compartments were sampled, each resulting in successful cytogenetic studies. Fluid was obtained under ultrasound guidance from amniotic fluid, fetal ascites and cystic hygroma fluid. Fluid from the hygroma itself may be the easiest compartment to analyze. 