Preanalytical Error in Reproductive Testing

How Important Is the Timing? Follow-Up A patient in the OB/GYN clinic had a presumptive diagnosis of infertility. The physician noticed while interpreting the patient’s LH, FSH, and estradiol results that all were all well below reference ranges for midcycle hormones: LH, 1.8 mIU/mL (reference range, 21.9 to 56.6 mIU/mL); FSH, 4.9 mIU/ mL (6.2 to 17.2 mIU/mL); and E2 , 135 pg/mL (150 to 750 pg/mL). However, the patient provided basal body temperature records that indicated a slight peak on days 15 and 16 of her ovulatory cycle. In addition, the hormone results were within reference range for day three of the ovulatory cycle, and the dates on the specimens appeared to correspond to day three of her cycle rather than midcycle. After further discussion with the patient, the nurse determined that she had not returned at midcycle but at day three for specimen collection. Thus a preanalytical error occurred because the specimen for LH, FSH, and estradiol testing was not collected on the correct day that corresponds to the middle of her ovulatory cycle, giving falsely lower results than the presumed midcycle results. The patient was given clearer instructions for returning the next month for repeat testing of these hormones, and an appointment for collection on the correct day of her ovulatory cycle was set.