Article History
Received: 9 August 2019
Accepted: 19 February 2020
First Online: 28 February 2020
Ethics approval and consent to participate
: This research was approved by the Institutional Review Board at Cayetano Heredia University (SIDISI number: 65778). Registration of births is mandatory in Peru, is required for obtaining birth certificates and does not require written consent. The birth registry database used for this study does not contain personal identifiers from participants.
: Not applicable.
: The authors declare that they have no competing interests.