On Sept. 17, Nike will launch its first sports collection for expectant mothers through its own web store in the U.S., Europe and Africa. Designed to support and motivate women in all phases of pregnancy and beyond to continue doing sports, the four-piece collection will be marketed under the label Nike M - M standing for Maternity. The collection comprises four main items: a top, a bra, a tank top and tights, all of which are equipped with special pregnancy features such as supporting inserts for the tummy or special fasteners for the nursing bra. Recycled polyester accounts for 78 to 88 percent of the materials used, depending on the product. Nike says it has conducted intensive research to develop the collection: Throughout the design process, the designers collected detailed feedback on fit, feel and function from nearly 30 athletes who were pregnant or postpartum, the company said.