RISKS FACTORS FOR ENDOMETRIOSIS IN THE RHESUS-MONKEY (MACACA-MULATTA)- A CASE-CONTROL STUDY

The autopsy records between 1980 and 1995 of 399 female rhesus monkeys (Macaca mulatta) at the Wisconsin Regional Primate Research Center we re examined. Spontaneous endometriosis was found in 81 (20 %) of the a nimals. The mean (+/-SD) ages at death for animals with and without en dometriosis were 20.7 +/-5.5 (range 10-35) and 13.4 +/- 7.7 (range 4-3 7) years respectively, Many of the animals had been exposed to experim ental procedures, including laparoscopies, hysterotomies and oestradio l implants, and these were examined as possible risk factors for endom etriosis. Of the 81 affected animals, 62 were matched to unaffected co ntrols for age at death (to within 1 year) and year of death (to withi n 2 years) and the effect of various factors on the development of end ometriosis was determined using conditional logistic regression, Expos ure to three or more oestradiol implants or one or more hysterotomies were both significant risk factors, with estimated relative risks of 9 .7 (95% confidence interval 2.5-37.2) and 5.8 (95% confidence interval 1.6-20.2) respectively. Animals that had been exposed to one or more laparoscopies showed no increased risk for developing endometriosis. T hese findings provide insight into the aetiology of the disease in wom en.