1. Having social norms or laws that force women to stay at home.
2. Having large economic inequality to make the cost of childcare services affordable to certain families.
2) Lower standards for supervision of children - as it was in the US in the 1970's, it's considered normal not to know where your 9-year-old is or what they're up to between breakfast and dinnertime.
3) Lower penalties for leaving the workforce for several years to take care of infants and toddlers - jobs that don't involve career progression or even necessarily what we'd consider formal employment (e.g. people working in their own fields or small market stalls).