Designer hormones improve treatments.

Women may find infertility treatments easier to take and may run less risk of multiple births thanks to new versions of reproductive hormones being designed at Washington University School of Medicine, St. Louis, Mo. "Women who take hormones prior to in vitro fertilization or for other infertility problems receive several injections daily," explains Irving Boime, professor of molecular biology and pharmacology and of obstetrics and gynecology. "But we have designed longer-acting versions that might be effective with fewer injections."

Fifteen percent of American couples are infertile. Many of the women who seek treatment receive a pituitary hormone called follicle-stimulating hormone (FSH), which promotes ovulation. The treatments can help those whose pituitary glands make too little FSH and can increase the number of eggs available for in vitro fertilization. Circulating in the bloodstream, FSH binds to cells in the ovary, but it only can be given by injections, which must be repeated because the hormone is broken down quickly,

FSH belongs to a family of hormones...