Although effective against various cancers, chemotherapy can damage the ovaries, possibly causing a permanent loss of fertility. Now, new research shows that treatment with two drugs can protect the ovaries from the toxic effects of chemotherapy, allowing these patients to become pregnant in the future.The drugs, known as D-Trp6-GNRHa and cetrorelix, work by blocking the hormone signals that stimulate the ovaries to function. As a result, the ovaries become more like those seen in girls who have not yet reached puberty. Previous reports have shown that the ovaries of these prepubertal girls are more resistant to the damaging effects of chemotherapy.At a briefing with reporters at the annual meeting of the Endocrine Society in San Diego, Dr. Marta Snajderova, from University Hospital-Motol in Prague, Czech Republic, noted that her team tested the two drugs on 19 teenage girls who were about to begin chemotherapy for leukemia or related cancers.