The incidence of spina bifida in Sweden 1973-2003: the effect of prenatal diagnosis.
Background: Many studies have been conducted on the accuracy of prenatal ultrasound diagnosis of foetal CNS-malformations. These studies were mostly hospital-based or, sometimes, multicentre studies. We present here a population-based study of the prenatal diagnosis of spina bifida in Sweden over a period of 31 years. Methods: We compared the number of newborns with spina bifida and the elective t