IDENTIFICATION OF ANOVULATION AND TRANSIENT LUTEAL FUNCTION USING A URINARY PREGNANEDIOL-3-GLUCURORAIDE RATIO ALGORITHM

The sensitivity and specificity of a urinary pregnanediol-3-glucuronid e (PdG) ratio algorithm to identify anovulatory cycles was studied pro spectively in two independent populations of women. Urinary hormone da ta from the first group was used to develop the algorithm, and data fr om the second group was used for its validation. PdG ratios were calcu lated by a cycles method in which daily PdG concentrations indexed by creatinine (CR) from cycle day 11 onward were divided by a baseline Pd G (average PdG/Cr concentration for cycle days 6-10). In the interval method, daily PdG/CR concentrations from day 1 onward were divided by baseline PdG (lowest 5-day average of PdG/CR values throughout the col lection period). Evaluation of the first study population (n = 6) resu lted in cycles with PdG ratios greater than or equal to 3 for greater than or equal to 3 consecutive days being classified as ovulatory; oth erwise they were anovulatory. The sensitivity and specificity of the P dG ratio algorithm to identify anovulatory cycles in the second popula tion were 75% and 89.5%, respectively, for all cycles (n = 88); 50% an d 88.3% for first cycles (n = 40) using the cycles method; 75% and 92. 2%, respectively, for all cycles (n = 89); and 50% and 94.1% for first cycles (n = 40) using the interval method The ''gold standard'' for a novulation was weekly serum samples less than or equal to 2 ng/ml prog esterone. The sensitivity values for all cycles and for the first cycl e using both methods were underestimated because of apparent misclassi fication of cycles using serum progesterone due to infrequent blood co llection. Blood collection more than once a week would have greatly im proved the sensitivity and modestly improved the specificity of the al gorithm. The PdG ratio algorithm provides an efficient approach for sc reening urine samples collected in epidemiologic studies of reproducti ve health in women.