With modern technologies like ultrasounds and pre-natal screenings, it’s becoming easier for parents to selectively terminate a pregnancy based on gender. And in countries around the world — from China to India, Vietnam, Korea, Georgia and Albania — this form of sex selection is on the rise. To explore this phenomenon, Worldview talks to Mara Hvistendahl, the Beijing-based correspondent for Science magazine and author of Unnatural Selection: Choosing Boys Over Girls and the Consequences of a World Full of Men. And, a BBC report reflects on the introduction of birth control in the U.K. 50 years ago.