By 1973, with the sexual revolution well underway, licensed doctors were increasingly
performing elective abortions for their patients, but they were worried about criminal and civil liability.
To better understand how the different pieces of the immune system develop, immunologists Florent Ginhoux and Naomi McGovern at the Agency for Science, Technology and Research (A * STAR) in Singapore and their colleagues studied tissue from nearly 100
elective abortions performed between 14 and 22 weeks of gestation.