el lactante, la lactante - a baby who breastfeeds, a baby who hasn't weanedSpanish example: No es posible mimar demasiado a un lactante antes de los 4 meses.
English example: It is not possible to spoil a breastfed baby less than four months old.
Source: el lactante, la lactante - a baby who breastfeeds, a baby who hasn't weaned (https://www.123teachme.com/spanish_feeds/word_of_the_day/2020/5/13)