Predictive value of sperm morphology and movement characteristics in the outcome of in vitro fertilization of human oocytes

Abstract

One hundred fourteen semen samples from Chinese males were analyzed for routine semen parameters including the semen volume, sperm count, percentage motility, and percentage normal morphology. Of these 114 samples, 54 also had movement characteristics of seminal and swim-up sperm evaluated by the computer image analyzer system (Cellsoft; Cryo Resources Co., New York). All semen samples were subjected to the swim-up procedure to harvest the motile sperm before inseminations of human oocytes. Fertilization was considered to have occurred when at least one oocyte was observed with two or more pronuclei. Semen samples were classified as infertile (0% fertilization rate;N=32) or fertile (>0% fertilization rate;N=82) before statistical analyses. There was a significant difference (Pr=0.3049;PPN=38) and the infertile (N=16) samples in percentage normal morphology of seminal sperm (67.8±1.8% vs 56.2±2.6%) and curvilinear velocity of swim-up sperm (89.2±3.5 vs 68.2±7.2 μm/sec). The fertilization rates correlated with the percentage normal morphology of seminal sperm (r=0.3868;Pr=0.3842;P<0.005). Multivariate stepwise discriminant analysis demonstrated that these two sperm parameters in combination were capable of predicting the fertilization rate with 74.1% accuracy. Our results indicate that seminal sperm morphology, coupled with computerassisted image analysis of movement characteristics of swim-up sperm, can help to predict the outcome of in vitro fertilization of human oocytes.