Text and Data Mining valid from 2020-02-08
Received: 27 December 2018
Accepted: 17 January 2020
First Online: 8 February 2020
Compliance with ethical standards
: The authors declare that they have no conflict of interest.
: The study was approved by the local ethical committee (code of ethical approval, 2015/182) and the participating institution, and written consent was obtained from the mothers.