Post-transfer spotting, also known as 'implantation spotting', is a natural consequence of the process of implantation of the fetal egg in the mucosa of the uterine cavity. Are they dangerous? What causes them? These questions are often asked by patients in early pregnancy. Today our expert, Jarosław Kaczyński, MD, specialist in gynaecology-obstetrics and endocrinology from the InviMed clinic in Warsaw, will provide the answers.

To understand what is the source of spotting, it is important to realise that the embryo in a woman's body is - metaphorically speaking - a guest. A guest who needs special treatment. In order for it to survive and develop properly, it needs to connect to the future mother's circulatory system.

Thanks to the 'integration' of the future placenta into the blood vessels, it is possible to create suitable structures that allow the exchange of nutrients and gases between the embryo and the mother. It is during this process that small, non-exacerbated spotting can occur. Stem cells are also involved in this process and are responsible for repairing damage to the endometrium. They are mainly involved in the embryo implantation process.

In the early stages of pregnancy, the immune system, which, as it were, plays an extremely important role in the maintenance of the pregnancy. It is thanks to its correct reaction to our "guest" that the white blood cells present in the mother's bloodstream do not destroy the embryo. Nevertheless, when spotting occurs, which is always considered a potential risk of miscarriage, the attending physician usually recommends taking progesterone. It is this hormone that is responsible in the pregnant woman's body for modulating the immune system, i.e. adapting it to the new situation. It is progesterone that 'promotes' the part of the protein-cell system that enhances the implantation process in the early stages of pregnancy.

Patients often ask at this stage if everything is OK. Doctors can actually only order one test during this period - a quantitative assessment of the level of beta hCG in the blood. Only appropriate increases of this hormone over time can confirm the normal development of the pregnancy. On the other hand, above the 6th week after conception, an ultrasound examination with a transvaginal probe can already be performed to confirm the pregnancy. Please note that all these tests should be decided by the attending doctor.