Routine ultrasound screening in pregnancy and the children's subsequent growth, vision and hearing.
OBJECTIVE: To test a hypothesis of no association between ultrasound exposure in early fetal life and growth or impaired vision or hearing during childhood. DESIGN: Follow up of eight to nine year old children born to women who participated in a randomised controlled trial on ultrasound screening during pregnancy. SETTING: Nineteen antenatal care clinics run by three central hospitals in Sweden from 1985 to 1987. POPULATION AND METHODS: Of 4637 eligible singleton pregnancies, 3265 (71%) were followed up through a questionnaire sent to their mothers. Analyses were performed both according to randomised groups and to ultrasound exposure. MAIN OUTCOME MEASURES: Parents' report of vision and hearing tests as recorded on child's record card. Parents' report of their child's weight and height at 1, 4 and 7 years of age. RESULTS: Reduced hearing was reported by 3.4% in the screening group compared with 3.5% in the nonscreening group (odds ratio [OR] 1.0; 95% confidence interval [CI] 0.67-1.41). The same prevalences were found when analysed according to ultrasound exposure (OR 1.0; 95% CI 0.67-1.42). Reduced vision was reported by 6.3% in the screening group compared with 7.8% in the nonscreening group (OR 0.8; 95% CI 0.60-1.03). Corresponding figures for ultrasound exposed and unexposed were 6.2% and 8.0%, respectively (OR 0.8; 95% CI 0.58-1.00). No statistically significant differences in body weight or height at 1, 4 or 7 years of age between screened and not screened children or between exposed and unexposed were found. CONCLUSION: This study found no association between ultrasound exposure in early fetal life and growth or impaired vision or hearing during childhood.