Single American mothers live in poverty 5 times more often than married parents.(National Women's Law Center, Poverty & Income Among Women & Families, 2000-2013) The topic is less contentious in Western European countries where all families enjoy more robust state-sponsored social benefits.
It has also been shown that children living in areas of South Africa are the very most likely to live with a single parent.
It is not to be confused that if you co-parent, both parents are playing a role of supporting and raising the child. Recent years have seen the increasing incidence and visibility of uncoupled women who choose to be single parents.
When single women seek to get pregnant intentionally in order to become single mothers by choice (or "choice moms"), they often seek an anonymous or known sperm donor.
There are even some that argue that a single parent family is not even really a family.
In American society, where living standard is very high, single moms and single dads are more likely to be poor, not only because they don't have help in the household, but also because they didn't have much money to begin with.