The Suckling (1990).
A teenage couple head to a brothel that also houses a room for illegal abortions. The aborted fetus is flushed down the toilet where, down in the sewer, it is exposed to toxic waste and begins to grow. Harboring a grudge against those that hurt it, the now mutated baby returns to kill! Directed by Francis Teri.
Starring: Frank Rivera, Marie Michaels. (90 mins).