Affiliation: | 1. Laboratory for Infectious Diseases and Screening, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands;2. Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands;3. Department of Obstetrics, Wilhelmina Children's Hospital, University Medical Centre Utrecht (UMCU), Utrecht, The Netherlands |