Chinese scientists using NIPT determined the correlation between genetic variations of the extracellular DNA of the fetus in the mother’s blood and pregnancy complications

Pregnancy complications affect maternal and fetal health. Various diseases, such as arterial hypertension and diabetes during pregnancy, often cause these complications. The main problems are finding markers for early detection of pregnancy complications. Reducing the time between the onset of complications and the initiation of appropriate treatment can prevent and reduce maternal and intrauterine morbidity and mortality. However, the value of screening for pregnant women with complications is uncertain due to the limited amount of knowledge about their contribution to the development of these pathologies.

The staff of the Department of Obstetrics of the University of Chongqing (China) reviewed the results of non-invasive prenatal testing (NIPT) of subchromosomal microdeletions and microduplications in a cohort of 3890 pregnancies without complications and 441 pregnancies with complications, including gestational diabetes mellitus (GDM), pre-pregnancy hypertension ( rupture of membranes (PRPO) and abnormalities of placental implantation (PIA).

In a study of gestational diabetes mellitus, genes from the alpha-defensin and beta-defensin families have attracted attention. Alpha defensins exhibit chemotactic activity and induce pro-inflammatory cytokines. They can be released into the extracellular medium after activation of granulocytes due to degranulation or cell death during inflammation. Meanwhile, in addition to their antibacterial and antiviral properties, beta-defensins can play a role in several protective, adhesive and regulatory functions. Moreover, several previous studies reported a relationship between type 1 and type 2 diabetes and the number of gene copies, as well as polymorphism and mRNA expression in some members of alpha and beta defensins, such as DEFA1, DEFA3, DEFB1.

Scientists also drew attention to pregnant hypertension. It is one of the most common complications during pregnancy and makes a significant contribution to maternal and perinatal morbidity and mortality.

Here, scientists studied the genes of protocadherins. Protocadherin has three gene clusters in humans, including Pcdhα, Pcdhβ, and Pcdhγ located in region 5q31 of chromosome 5. In some studies, protocadherin deficiency has been shown to alter the development, morphogenesis, and transcriptional profile of the placenta in mice. Thus, protocadherin deficiency can lead to placental lesions, which were defined as maternal vascular lesions, which were more common in pregnancies complicated by hypertensive disorders.

Premature rupture of the membranes is the outflow of amniotic fluid after rupture of the amnion before the onset of labor. For this pathology, scientists have identified three genes SFTPA2, SFTPD and SFTPA1. The proteins encoded by these genes are responsible for the synthesis of surfactant and are part of the innate immune response against inhaled microorganisms and chemicals.

Disorders of placental implantation, including placenta previa, can have catastrophic complications for both the mother and the fetus, closely associated with premature birth, which leads to significant perinatal morbidity and mortality. According to genetic analysis, the researchers report that genes such as MEF2C and TM6SF1 are involved in the invasion and differentiation of trophoblasts.