Looks like San Francisco, Seattle and San Jose children are born to parents with six-figure household incomes.
These figures are for kids with American born parents.
While, 18 American cities have the median family income under $50,000 when the children are born.
Median family income among households with children by family nativity | KIDS COUNT Data Center
The median household that has a kid in Detroit makes $20,000
Cleveland $23,000, Memphis $29,000, Milwaukee $33,000
On the other side of the coin...
San Francisco $155,000, Seattle $124,000, San Jose $112,000, Austin $81,000, San Diego $79,000
Yup, in 2017 a household making $30,000 can afford to raise kids without government welfare money. I don't think so.