Placental proteins may be associated with spontaneous preterm birth

In the new study, the group of paediatric and genetic researchers showed that the Alpha-1 antitrypsin protein levels are lower in the placentas of premature babies compared to the placentas of full-term babies.

Preterm birth is a worldwide problem, as more than one in ten babies are born prematurely, i.e. before 37 completed weeks of pregnancy. Preterm birth puts the child at risk of lifelong illness and significantly increases the risk of mortality.

The aim of the study was to identify placental proteins and examine the possible connection of their levels to spontaneous preterm birth. One of the proteins found in low levels in the placentas of premature babies was the Alpha-1-antitrypsin protein. The purpose of Alpha-1 antitrypsin is to protect tissues in the event of tissue damage or bacterial infections. Its level increases in the case of inflammation and tissue damage. In addition, it has been observed that its level increases in maternal blood during pregnancy.

It was established in the study that Alpha-1-antitrypsin is present in the placental tissue, both inside the placenta cells and in structures outside the cells. This connective tissue structure acts as a kind of “adhesive” that attaches the placenta to the wall of the uterus, and it has been suggested in previous studies that it plays an important role in the immune system interaction between the mother and foetus. The study showed that Alpha-1 antitrypsin may have a protective effect on the connective tissue structures of the placenta.

The researchers believe that lower levels of Alpha-1 antitrypsin pose a risk of tissue damage to the structures necessary to maintain pregnancy. This can lead to spontaneous preterm birth.

There is currently no effective way to predict prematurity or prevent preterm birth. The researchers’ next step will be to seek to determine which factors lead to abnormal levels of Alpha-1 antitrypsin and whether an Alpha-1 antitrypsin preparation could be used to impact the onset of labour.

The study was published in the prestigious BMC Medicine journal.

Research publication: Tiensuu H, Haapalainen AM, Tissarinen P, Pasanen A, Määttä TA, Huusko JM, Ohlmeier S, Bergmann U, Ojaniemi M, Muglia LJ, Hallman M, Rämet M. Human placental proteomics and exon variant studies link AAT/SERPINA1 with spontaneous preterm birth. BMC Med 20, 141 (2022). https://doi.org/10.1186/s12916-022-02339-8