Received: 8 January 2020
Accepted: 28 May 2020
First Online: 3 June 2020
Ethics approval and consent to participate
: Our database was approved by the French Data Protection Authority (CNIL n°912033 and CCTIRS) and by a French research ethics committee. Maternal consent was systematically requested after birth management.
: Not applicable.
: The authors declare that they have no competing interests.