Celecoxib treatment reduces oocyte nuclear maturation. Oocytes were obtained from monkeys experiencing controlled ovarian stimulation after treatment for 36 hours with either hCG alone (dark bars; n=12 monkeys) or hCG and the COX2 inhibitor celecoxib (light bars; n=6 monkeys). Oocytes were assessed for nuclear status (germinal vesicle intact (GV), germinal vesicle break down (GVBD), or presence of a single polar body (MII)) by light microscopy. Data are expressed as the percent of total cohort of oocytes which are at the indicated stage. Within each class of oocytes, differences between treatment groups are indicated with an asterisk (*) as determined by unpaired t-test, p<0.05. For oocytes from animals receiving hCG alone, b>a as determined by ANOVA and Newman-Keuls’ test, p<0.05.