The so-called 'baby whisperer' industry is back in the spotlight, with calls for the practice to be regulated.
Baby whisperers, also known as sleep consultants, offer advice to tired parents on ways to get their babies to sleep better.
Baby Sleep Practitioners co-founder Elspeth Witton told Newstalk ZB's Larry Williams many consultants are giving out unhealthy advice.
"There is no regulation of this industry, so anyone can claim that they can help you with your baby's sleep.
"We think anyone who's helping you with your baby's sleep needs to have a medical background."
Wilton said consultants giving out unhealthy advice could actually be causing harm to babies, if parents take that advice.
"A lot of people are advocating advice that's not evidence-based and does have negative outcomes for babies and their caregivers.
"People generally maybe aren't aware of what they're actually getting when they're employing a baby sleep consultant of varying skill level."