Antibodies within the cervical mucus

These Y-shaped molecules take on an important role in the body. They help the body defend itself from bacteria and viruses by recognizing and binding to very small structures on their surfaces. The antibodies can be responsible for an inability to conceive if they are found in the mucus that is formed in the uterine neck prior to ovulation (the so called cervical mucus).  This mucus is viscous and thready several days before ovulation. Some women use these signs to identify their fertile days.

The presence of sperm-targeting antibodies in the cervical mucus can be a reason why some couples may be unable to achieve pregnancy.

Sperm cells and the mucous of the cervical canal (cervical mucus)

After intercourse in the days around the ovulation the sperm cells move into the mucus surrounding the cervical canal. From there, they move through the uterus into the fallopian tube to fertilize the egg cell. In rare cases, antibodies against sperm cells can be found in the mucus. This makes it impossible for the sperm cells to pass through the cervical canal.

In order to find out whether such antibodies are present, a small amount of mucus is extracted on the day of the ovulation with a pipette. Additionally, a sperm sample is required from the partner.

The laboratory then tests whether the sperm cells can enter the mucus unhindered and move forwards. If a large amount of sperm cells die it can be concluded that antibodies are present.

This test is called sperm-mucus interaction test or Kremer test.

In such cases, an insemination can provide higher chances as the sperm cells are flushed into the uterine cavity which lies behind the cervical canal with its antibody barrier.