1 Department of Obstetrics and Gynaecology, CHRU de Lille (centre hospitalier régional universitaire de Lille [Lille Regional University Hospital Centre]), avenue Eugène-Avinée, 59037 Lille cedex, France.
2 Department of Obstetrics and Gynaecology, CHU Bicêtre (centre hospitalier universitaire de Bicêtre [Bicêtre University Hospital Centre]), AP-HP (Assistance Publique-Hôpitaux de Paris [Public Healthcare-Paris Hospitals]), 78, rue du Général-Leclerc, 94270 le Kremlin-Bicêtre, France; University Paris Sud 11 Orsay, 63, rue Gabriel-Péri, 94270 le Kremlin-Bicêtre, France; Inserm U1018, CESP (Centre of Research in Epidemiology and Population Health, 82, rue du Général-Leclerc, 94270 le Kremlin-Bicêtre, France.