According to this document (page 3), US is an exception when it comes to total paid leave related to maternity (paid maternity leave + paid parental and home care leave available to mothers). The OECD countries average is about one year (55.2 weeks).
According to Wikipedia, there seem to be some benefits associated with paid maternity leave:
A Harvard report cited research showing paid maternity leave “facilitates breastfeeding and reduces risk of infection”, but is not associated with changes in immunization rate. This research also found that countries with parental leave had lower infant mortality rates. Returning to work within 12 weeks was also associated with less regular medical checkups. Data from 16 European countries during the period 1969-1994 revealed that the decrease of infant mortality rates varied based on length of leave. A 10-week leave was associated with a 1-2% decrease; a 20-week leave with 2-4%; and 30 weeks with 7-9%. The United States, which does not have a paid parental leave law, ranked 56th in the world in 2014 in terms of infant mortality rates, with 6.17 deaths per every 1,000 children born.
Question: Why is there no paid maternity leave in United States? (as opposed to the the vast majority of developed countries)