"When we took office we swore a duty to uphold both the federal and state constitutions, and this law appears just as unconstitutional as the last few attempts to impose such restrictions," Carter said.
Hill, a Republican, did not respond to a request for comment on the pronouncement by the three Democratic prosecutors.
The attorney general, on behalf of the state health department and the Tippecanoe County prosecutor, still is expected to defend the law enacted in March by the Republican-controlled General Assembly and Republican Gov. Eric Holcomb.
Senate Enrolled Act 340 requires all Indiana doctors and hospitals to compile and submit a detailed report every time a woman seeks treatment for a physical or psychological condition that is in any way connected to a past abortion.
The lawsuit argues the statute is unconstitutional because the law's definition of abortion complications "is so broad as to be meaningless."
In addition, it claims the law imposes "vague and uncertain standards" that also are "irrational and arbitrary" since abortions repeatedly have been recognized as safe, with minimal adverse outcomes.
The prosecutors were sued to block enforcement of the new law as Planned Parenthood operates abortion clinics in their counties.