The decision to give a young woman cyclophosphamide for life-threatening complications of systemic lupus or vasculitis is one of the hardest decisions in rheumatology. The long-term consequences include premature ovarian failure and thus sterility, as well as an increased risk of malignancy. The strongest risk factor for ovarian failure is the patient’s age at administration of this chemotherapy. Several small studies have indicated that use of GnRH agonists prior to and during chemotherapy could potentially increase the chances of preserving fertility, however, the results were mixed, the studies small. Clowse and colleagues performed a very nice systematic review and meta-analysis of all the existing studies of use of GNRH-agonists and in women receiving chemotherapy to achieve a more precise estimate of the potential ovary-protective effect. They identified 9 studies of varying sizes, including 366 women treated for autoimmune diseases or cancer. 93% of those treated with GnRHa during chemotherapy maintained ovarian function and 22% later achieved pregnancy vs. 48% and 14% respectively of those not treated maintained ovarian function. The summary relative risk for maintenance of ovarian function was 1.68 (95% CI 1.34-2.1), and the summary RR for later fertility was 1.65 (CI 1.03–2.6). This meta-analysis and the studies it included did not rigorously examine potential side effects such as ovarian hyperstimulation with initial use, or osteoporosis. Nonetheless, based on their results, the meta-analysis authors recommend offering GnRHa therapy to premenopausal women who desire future fertility as they prepare to undergo chemotherapy, a practice that is not universally adopted in rheumatology. Karen H. Costenbader, MD, MPH