US scientists have successfully used a laser beam in clinical trials to promote pregnancies in women. The In Vitro Fertilization Workstation used in the procedure is manufactured by Cell Robotics International Inc. in Albuquerque, N.M. The instrument is being tested by the US Food and Drug Administration. The computer-controlled instrument not only helps diagnose the eggs and embryos before they are chosen for fertilization, but increases the chances that the embryo will hatch. As women age, this shell around the egg often becomes tough. The laser beam penetrates the thin shell of an embryo so that it will be more likely to hatch inside a womb. In tests conducted in the US, four patients over the age of 39 who previously had undergone unsuccessful classical in vitro fertilization, underwent laser-assisted hatching. Of the four women, one became pregnant. Each year up to 100,000 women undergo in vitro fertilization.