Purpose: The aim of this study was to compare the reliability of the methods conventionally used to identify low levels of blood contamination in human follicular fluid (hFF) as applicable in the clinical environment.
Methods: Follicular fluid (n = 339) and plasma samples (n = 20) were collected from patients (n = 138) attending the Centre for Fertility Studies, HF Verwoerd Hospital, University of Pretoria, South Africa. hFF blood contamination was assessed by means of (a) visual inspection, (b) hematocrit (Hct), (c) spectrophotometric analysis, (d) spectrophotometric hemoglobin kit, and (e) Combur-9-test urine sticks.
Results: (1) Neither hematocrit nor spectrophotometry provided reliable detection at low levels of blood contamination. (2) Visual inspection presented with a better discriminatory ability than either Hct or spectrophotometry. (3) Combur-9-test sticks identified up to 50% of blood-contaminated fluids. (4) Spectrophotometrically determined hemoglobin levels presented with weak discriminatory abilities for detecting blood-contaminated fluids.
Conclusions: Visual inspection as performed in this study provides a fast and relatively reliable method for the determination of blood-contaminated hFFs. In a laboratory environment, however, it would be recommended that a combination of visual inspection, Hct, and spectrophotometric evaluation be employed for the selection of blood-free fluids.