Should parents be allowed to choose the sex of their baby?
(CNN) -- Many couples trying to conceive a child have at least some inkling of whether they want a girl or a boy. These preferences have made some resort to less-than-surefire methods, from taking vitamins to timing when they have sex in order to influence gender. But with the growing popularity of in vitro fertilization, more and more parents-to-be are gaining the ability to determine, with almost 100% certainty, the gender of their baby. This week, model Chrissy Teigen and her husband, singer John Legend, announced they not only wanted a girl but chose the gender of their baby, a daughter, due this spring.