Based on a Scottish study of 22.343 pregnancies in Scottish mothers and their daughters, scientists predict, that there is a genetic predisposition, which affects premature birth. Premature birth is a leading cause of death in newborns and can lead to long-term problems such as cerebral palsy. The researchers found that mothers-to-be who had been born prematurely were, on average, 60% more likely to have a premature baby if it was their first pregnancy. For any subsequent pregnancies their risk was 50%. Apart from genetic risk, several other factors also influence spontaneous preterm like age at delivery younger than 20 years, lower socioeconomic status, smoking more than 10 cigarettes per day and body mass index 19 kg/m2 or less.