Human sperm head morphometric distribution and its influence on human fertility

Abstract

Objective: To study the distribution of live sperm head size in semen and sperm preparations as a predictor of fertility. Design: Prospective blind clinical trial. Setting: Academic tertiary referral center. Patient(s): One hundred fifty-five patients undergoing IVF treatment. Females with conditions negatively influencing fertilization were excluded. Intervention(s): Morphometric analysis (head area, major axis, minor axis, and elongation ratio) of video images of sperm in semen and swim-up preparations used for IVF treatment was performed with a Hamilton-Thorne analyzer V 8.1 (Hamilton-Thorn Research, Beverly, MA). Main Outcome Measure(s): Oocyte fertilization. Result(s): Seventy-four percent of patients achieved fertilization. Fertilizers and nonfertilizers had different sperm head area distribution. The fertilizers had a significantly smaller interquartile range of sperm head area and of major axis in both semen and sperm preparation compared with the nonfertilizers. A subgroup of men who had fathered a child naturally had a more uniform sperm head area in semen with a significantly smaller median compared with those who failed to father a child naturally with their healthy female partner. We used multiple logistic regression applying forward stepwise selection of variables in building three predictive models of probability of fertilization. Conclusion(s): Successful IVF or history of fathering a child was associated with a more uniform sperm head area in semen and sperm preparation.