Placental proteins (human chorionic gonadotropin, human placental lactogen, pregnancy-specific beta 1-glycoprotein, and placental protein 5) in seminal plasma of normal men and patients with infertility.

Placental proteins, including human chorionic gonadotropin (hCG), human placental lactogen (hPL), pregnancy-specific beta 1-glycoprotein (SP1), and placental protein 5 (PP5) have been detected in human seminal plasma of 20 normal men and 42 patients with infertility. Levels of hPL, SP1, and PP5 were similar in these groups. There were significantly higher levels of hCG in subjects with normal sperm counts than in those with oligospermia or azoospermia. The levels of PP5 in seminal plasma showed an association with sperm motility, suggesting that PP5 may have a significant biologic function in the maintenance of sperm motility.