A full-term pregnancy is around 40 weeks, but one in 13 is born premature—before 36 weeks. Data from researchers at the Institute of Psychiatry at King’s College London and the Karolinska Institute in Sweden show out of 10,523 people admitted to the hospital with a psychiatric disorder, 580 were born prematurely. Full-term children had a two in 1,000 chance of being admitted. The risk was four in 1,000 for premature babies born before 36 weeks and six in 1,000 for babies born before 32 weeks. “I don’t think parents should be worried, but we know that preterm birth confers an increased vulnerability to a variety of psychiatric conditions and perhaps parents should be aware of this and monitor early signs of later more serious problems,” said Chiara Nosarti, a researcher on the study.