Received: 24 May 2017
Accepted: 14 February 2018
First Online: 27 February 2018
Ethics approval and consent to participate
: This study was exempt from Institutional Review Board approval as we used only anonymous data from the LEMMoN-study and the Dutch Perinatal Register that cannot be related to any individual. The LEMMoN-study was centrally approved by the medical ethics committee of Leiden University Medical Center (P04-020; 8 March 2004). Approval to use data from the Dutch Perinatal Register (LVR-2) was obtained.
: Not applicable.
: Two of the authors are members of the editorial board of the journal: JvR is a section editor and TvdA an associate editor.
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