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 .
C0032974
placental proteins
C0033002
pregnancy-specific beta 1-glycoprotein