This document summarizes a presentation on searching for semen phenotypes that are predictive of impaired male fecundity. The study analyzed data from 501 couples in the Longitudinal Investigation of Fertility and the Environment study. It found that several semen morphology measures, including abnormal tail shape and head shape, were weakly associated with longer time to pregnancy of over 6 months after adjusting for factors like age, smoking, and previous pregnancies. However, semen phenotypes provided only modest predictive value beyond traditional risk factors. Larger studies are needed to better understand variations in male fecundity.