1 Assistance Publique Hôpitaux de Paris (APHP), Department for Medical Information System, for Trousseau, La Roche Guyon and Rothschild Hospitals, Academic Hospitals of eastern Paris, 75012 Paris, France; Pierre et Marie Curie University, Paris VI, and INSERM U1153, Obstetrical, Perinatal and Pediatric Epidemiology Research Team, Research Centre for Epidemiology and Biostatistics Sorbonne Paris Cité, Paris Descartes University, Paris, France. Electronic address: annie.serfaty@trs.aphp.fr.