Note: SERUM sample MUST be used for PMSG
PMSG is produced from the endometrial cups from about day 40 – 120 post covering and is the next available pregnancy test. PMSG is prone to false positives as, if the foal dies, the endometrial cups continue to produce PMSG for some time. O-SO4 should be used to confirm pregnancy and the presence of a live foal after 100 days.