The Collaborative International Dictionary of English v.0.48:

Abortionist \A*bor"tion*ist\, n.
   One who performs or procures abortion; among medical
   personnel, also called an abortion provider.

   Note: The word abortionist has negative connotations from the
         time when the practise was illegal in the United
         States, and the latter term is preferred among those
         who do not consider the procedure as morally
         reprehensible.
         [1913 Webster +PJC]

WordNet (r) 3.0 (2006):

abortionist
    n 1: a person (who should be a doctor) who terminates
         pregnancies