BOULDER, Colo. — Behind bullet-proof doors in a generic office park is one of only five clinics in the country where women can access the rarest — and most controversial — abortion procedures.

Women come here desperate, says Dr. Warren Hern, who has run the Boulder Abortion Clinic since 1975.

“It ranges from the 12-year-old kid who’s pregnant from her stepfather to the 45-year-old woman who desperately wants to have a baby and finds out that she has a fatal illness that is…