A remarkable proportion of pregnancies are unplanned — about a third of all pregnancies in New Hampshire, to almost 60% in Mississippi. And those pregnancies cost a lot of money, from prenatal care to medical care and so forth after birth, a lot of which gets picked up by the taxpayer — 80% of unplanned births in Georgia, Mississippi and Oklahoma were paid for by state and federal dollars.
(In Colorado, about 36% of pregnancies are unplanned; about 68% of those are paid for with public assistance, totaling $237MM in costs to the taxpayers.)
It seems clear that a lot of those costs come from lack of birth control use or use of poorly reliable birth control methods.
Public spending on birth control and family planning seems to save already a lot of precious tax dollars, but that's deemed a Tool of the Devil (the "public spending" as much as the "birth control" parts) in some areas of our political landscape. The solution from those parts instead seems to be that sex should be reserved only for times of personal economic prosperity and marital security, which is very nice but doesn't seem terribly realistic.
I guess we'll just keep birthing babies and wringing our hands over it.
Unplanned pregnancies cost taxpayers $21 billion each year
Mapping the cost of unplanned pregnancy in the U.S.