What could be the cause of an abnormal postcoital test?

• Was it done at the right time? A PCT can only be done around the time of ovulation. Without ovulation, the reading of the PCT is unreliable.
• Abnormal cervical mucus quality: High-viscosity and/or low-volume mucus can block sperm.
• Infection in either partner (indicated by white blood cells in the mucus).
• Sperm antibodies can cause the sperm to die, to agglutinate (clump together), and/or to shake.
• Abnormal semen: Sperm antibodies produced by the man as well as infections in the man can adversely affect test results, as can a low sperm count and poor motility.
• Poor coital technique (for example, the penis does not enter the vagina).
• Ejaculation disorders can also prevent the sperm from reaching the cervix.