Three months into her pregnancy, the woman in my office worried that her fetus might have Down syndrome. She wanted a definitive diagnosis, so I referred her to a doctor who inserted a 3 1/2-inch needle into her uterus and sucked up cells from her placenta; a procedure called chorionic villus sampling, or CVS. Two days later, I called to tell her that preliminary results showed her fetus didn't have Down syndrome. Read the full article here.