No differences in IQ was determined. However, in a medical study, four years later, those with delayed cord clamping showed modestly higher scores in social skills and fine motor skills and this was significant improved for the boys. Much of the research has focused on preterm infants, who appear to benefit most from delayed cord clamping. They needed fewer drugs to support blood pressure and fewer blood transfusions. Also, the placental blood is rich with stem cells, which could help to repair any brain damage the baby might have suffered during a difficult birth. On the other side, delayed cord clamping is potentially dangerous because polycythemia, a very high red blood cell count, can occur. For the instant, at this study participated 263 healthy Swedish full-term newborns. The researchers think it must be repeated in developing countries where iron deficiency may be more likely.