A poster with information about the Zika virus hangs on a wall as a pregnant woman undergoes an ultrasound treatment at the Social Security Institute maternity ward in Guatemala City. (Saul Martinez/Bloomberg)

The 23-year-old mother was pregnant with her fourth child when she contracted a dreaded disease. Thousands of women who had been similarly infected had gone on to have children with birth defects ranging from heart problems to blindness to microcephaly, an abnormally small head. Knowing that her baby was likely to suffer from severe disabilities, the young mother, the wife of a construction worker, decided to get an abortion. It was illegal where she lived, but her doctor agreed.

“I felt that it would be very cruel to the baby,” the patient later said in court testimony recounted in the book "Before Roe v. Wade." “I don’t think I could do this to a child. I couldn’t make a child suffer. And I don’t think I could have lived with myself knowing that I could have done something about this and I didn’t.”

This wasn’t a reaction to Zika virus, the mosquito borne illness that has rapidly escalated into a public health emergency.

It was a reaction to German measles. In 1970. In Minnesota.

“Women in early pregnancy or even before they knew they were pregnant and were trying to conceive were terrified of catching it because it had ... devastating impacts on fetal development,” said Linda Greenhouse, a lecturer at Yale Law School who recounted the case in the book "Before Roe v. Wade." “It was one of a number of things that made abortion sort of dinner table conversation, when it previously had not been talked about at all.”

Zika can seem like yet another global health crisis, its biggest connection to the United States the possibility it could spread here. But recent history suggests that the alarm and fear over a disease that has already begun to put some pregnant women in the difficult dilemma of considering abortion, while facing strict abortion laws, isn’t quite as foreign as it seems.

Public health officials have not suggested that pregnant women with Zika should get abortions, but neither did they suggest it in the mid-1960s, when 20,000 infants were born with German measles. In fact, abortions were only allowed if the mother's life was at stake in many places. Still, an outbreak of German measles, also known as rubella, became an important factor in helping to change public consciousness and perception of abortion in the United States.

Concerns about Zika virus have triggered travel alerts and calls by some governments for women to delay pregnancy. A judge in central Brazil said that women could legally have abortions if their fetuses had microcephaly, the New York Times reported, and scholars were preparing a case to go to the country's highest court. (It's important to note that the link between Zika virus and microcephaly is strongly suspected, but not proven.)

"One, maybe unanticipated, result of all this might be possible changes in the public sentiment in these countries, about the status of women about the availability of abortion," said Dov Fox, an associate professor at the University of San Diego School of Law. "There is a very close precedent in the U.S. for this kind of change."

In the United States, there were numerous factors that transformed abortion from a topic that was outlawed, spoken about in hushed tones. But rubella, a disease with an estimated 12.5 million cases in the country from 1964 to 1965, helped to change that discussion.

In 1966, The Washington Post ran a story about doctors breaking the law to perform abortions of severely deformed fetuses, noting that German measles was the best known and most common cause of infants with severe birth defects.

"Science tells us the probable consequence of rubella virus infection of a mother early in pregnancy. With that knowledge, we can no longer pretend innocence, even about the consequences of leaving that pregnancy unattended," Joshua Lederberg wrote at the time.

The Minnesota abortion case four years later became an important test case for challenging restrictive abortion law. The physician, Jane E. Hodgson, asked a federal judge for permission to do the abortion on her patient, Nancy Kay Widmyer, but when the judge demurred to act quickly, she proceeded before the pregnancy progressed further and was arrested.

In their book, "Before Roe v. Wade," Greenhouse and her co-author, Reva Siegel, reprinted portions of an article Hodgson published in the alumni magazine of the Mayo Clinic in the run-up to her trial. Hodgson wrote that she had performed fewer than a dozen abortions in 23 years of practicing medicine, but felt that when the young mother came to her she was a perfect test case to challenge the law.

"I did not send her to England or Mexico or Montreal. She could have afforded it-- but what about future patients who could not?" Hodgson wrote. "And what about respect for law? We both knew we could not dodge the issue."

Hodgson asked a federal court judge for protection -- an injunction to prevent being prosecuted for performing an abortion. The judge delayed, and Hodgson performed the abortion two weeks later.

Hodgson was indicted by a grand jury and sentenced to a month in jail. Her sentence was overturned after the Supreme Court decided Roe V. Wade in 1973.

To some bioethicists, rubella provides an interesting parallel to what is happening in Latin America today, where abortion is restricted in many countries, but does occur.  According to a report by the Guttmacher Institute, of the 4.4 million abortions performed in Latin America and the Caribbean in 2008, 95 percent were clandestine, performed under conditions that don't meet medical standards. The number of abortions induced by medication, a relatively safe form of clandestine abortion, has increased.

In the wake of the emergency announcement, Women on Web, a nonprofit that sends pills to women who are in countries where they do not have access to abortion services, announced it would provide women with a confirmed Zika infection the pills for free.

Rebecca Gomperts, the director of Women on Web said that after the Zika news emerged, there was an uptick in the 10,000 email requests they receive each month for medical abortions, driven by women in Zika-afflicted countries.

"What we are really concerned about is the fact that women who are infected with Zika will start looking for an abortion that is unsafe," Gomperts said in an interview.

U.S. history may not be much of a guide to what is happening in Latin America at the moment. The countries are different culturally and economically. But as the crisis continues to evolve, if governments proscribe whether women should have children, it will likely force at least some discussion of reproductive health issues into the open.

"What women face in these challenges have been there for awhile, and are big challenges to women before Zika was introduced," said Jennifer Kates, a vice president at the Kaiser Family Foundation. "If anything, Zika is raising awareness of the challenges women face every day."