According to the law, having an abortion carries a penalty of 5 to 10 years in prison, depending on the circumstances, while doctors and others who perform an abortion or assist with one could face up to 15 years, prosecutors say. In practice, however, fewer than 500 cases have been prosecuted over the last several years.

“I think there is a certain sensitivity to the social conditions behind these abortions, such as poverty or rape or teenage pregnancy,” explained Paula Vial, a lawyer and former public defender in Santiago.

Beyond the legal consequences, the 30 hot line volunteers are keenly aware of the social ramifications of taking an active role in such a polarizing issue. They wear masks when promoting the hot line at public gatherings, and are often vague about the details of their volunteer work in their daily lives. Many fear losing their jobs or driving a wedge into personal and family relationships. Indeed, Ms. Erpel was the only volunteer willing to go on the record about her work with the hot line, and even she is usually circumspect about it.

“It’s complicated,” she explained. “I’m open about being in an organization, but not necessarily that I work directly with abortion.”

Abortion was not always a clandestine affair in Chile. The current law that strictly bans it was one of the final acts of the dictatorship. In 1989, shortly before relinquishing power, Gen. Augusto Pinochet ended a tradition of legal abortion dating to 1931, in which a pregnancy that threatened a woman’s life, or a fetus that was not viable outside the womb, could be terminated. Chile’s law now is one of the strictest in the world.