Discrepancies in sperm count using improved Neubauer, Makler, and Horwells counting chambers

Semen analysis still remains an important diagnostic procedure in male infertility evaluation. For the purpose of standardization and uniformity in the interpretation of sperm count results, the accuracy of three different counting chambers (improved Neubauer (IMN), Makler, and Horwells) were evaluated. Semen samples produced by 50 men were analyzed with the three different counting chambers using World Health Organization guidelines. The overall precision values of sperm count were: IMN 9.7%, Makler 5.9%, and Horwells 7.1%. The mean sperm counts (+/- SEM) were 78.6 (+/- 10.1), 119.1 (+/- 14.1), and 211.5 (+/- 27.5) million spermatozoa/ml respectively. Statistically significant differences were revealed when the sperm count results obtained with the different counting chambers were compared, i.e., IMN vs Makler (P < 0.05), IMN vs Horwells (P < 0.001), and Makler vs Horwells (P < 0.01). The sperm count results obtained from the 50 samples were classified into four subgroups (A = 1-20, B = 21-50, C = 51-100, and D = > 100 million spermatozoa/ml) using IMN as a reference chamber. Errors reflected as progressively poor SEM of sperm count (A = 1.1, 3.2, 4.1; B = 3.0, 6.1, 12.4; C = 3.4, 17.0, 23.9; and D = 14.1, 21.3, 46.3) were observed for IMN, Makler, and Horwells counting chamber respectively in each group. This study revealed that inherent errors abound when different counting chambers are used for sperm count. While IMN gave the lowest sperm count, Horwells recorded the highest. Makler counting chamber gave midway values and conforms with recommendations in the literature about its accuracy.