SERUM PROGESTERONE PREDICTS ABNORMAL GESTATIONS IN CLOMIPHENE CITRATECONCEPTION CYCLES AS WELL AS IN SPONTANEOUS CONCEPTION CYCLES

Objective: To determine if a ''discriminatory'' P concentration could be established that predicted abnormal early pregnancies in clomiphene citrate (CC)-conceived cycles. Design: Progesterone concentrations of gestations between 28 and 49 days from last menstrual period in both spontaneously conceived and CC-stimulated cycles were analyzed using a relative-operating characteristic (ROC) curve. Interventions: Serum P concentrations were measured in 222 pregnant patients from the first 49 days of gestation. One hundred sixteen patients conceived in a spon taneous cycle and 106 patients conceived in CC-treated cycles. Two by two contingency tables were used to calculate the true-positive (sensi tivity) and false-positive rates at 20 specific P concentrations. A RO C curve was then generated by plotting the sensitivity of the test aga inst the percent of normal patients incorrectly classified (false posi tive) at each P level. The best discriminatory value was estimated in each curve at a point of high sensitivity associated with a minimal fa lse-positive value. The areas under the curve and SE were calculated f or each group and compared by the critical ratio z-test. Results: The best discriminatory P concentration was 10 ng/mL (32 nmol/L) for spont aneously conceived pregnancies and 30 ng/mL (95 nmol/L) for CC-treated pregnancies. The area under each ROC curve was significantly predicti ve. Comparison of the two curves indicated that the ability of P measu rements to predict gestational complications was independent of follic ular stimulation. Conclusions: Follicular stimulation with CC increase s the discriminatory P value that predicts gestational normalcy but do es not alter the clinical utility of the test.