Babies cry at night to stop parents from trying for another

Babies who wake up at night to breastfeed may be actually trying to delay the birth of a sibling, a new study suggests.

According to the research, infant’s tendency to wake up in the night may have been a tactic to make mothers breastfeed more, thus reducing their fertility and limiting the number of siblings that will be born, which in turn improved a child’s chances of survival.

Researchers argue that infants that wake frequently at night to breastfeed are delaying the resumption of the mother’s ovulation and therefore preventing the birth of a sibling with whom they would have to compete.

It has already been documented that smaller gaps between the births of siblings are associated with increased mortality of infants and toddlers, especially in environments where resources are scarce and where infectious disease rates are high, researchers said.