In recent years evidence has been accumulated showing that miRNAs can act as potential biomarkers or targets for therapy of preterm birth, one of the most important problems in modern obstetrics. We have performed a prospective study of the miRNA profile in the plasma during the first and second trimesters in pregnant women with high risk of preterm birth (n = 13 cases and n = 11 controls). For the study group plasma blood samples at 9–13 weeks before diagnosis and at 22–24 weeks after start of therapy were selected. Using high-throughput sequencing technology we detected differences in the levels of 15 miRNAs (3 upregulated—hsa-miR-122-5p, hsa-miR-34a-5p, hsa-miR-34c-5p; 12 downregulated—hsa-miR-487b-3p, hsa-miR-493-3p, hsa-miR-432-5p, hsa-miR-323b-3p, hsa-miR-369-3p, hsa-miR-134-5p, hsa-miR-431-5p, hsa-miR-485-5p, hsa-miR-382-5p, hsa-miR-369-5p, hsa-miR-485-3p, hsa-miR-127-3p) (log₂(FC) ≥ 1.5; FDR ≤ 0.05) during the first trimester compared with the control (non-high-risk of preterm birth pregnant women). All downregulated miRNAs in the first trimester from the placenta-specific C14MC cluster. During the second trimester no differentially expressed miRNAs were found. Our results suggest that the miRNA profile in plasma during early pregnancy may predict a high risk of preterm birth, which is important in preventing gestational problems as early as possible.

Extracellular vesicles (EVs) are double-membrane vesicles that facilitate intercellular communication and play a pivotal role in both physiological and pathological processes. A substantial body of evidence suggests that EVs play a role in the pathogenesis of various pregnancy complications. Because EVs can be detected in the peripheral blood, they are potential biomarkers for the early diagnosis of pregnancy complications and foetal developmental disorders. The majority of studies have demonstrated a correlation between alterations in the concentration of EVs and changes in their contents and the occurrence of pregnancy complications. Despite the current limitations in establishing a clear link between these findings and the pathogenesis of the disease, as well as the lack of sufficient evidence to support their use in clinical practice, it is noteworthy to highlight the potential role of specific miRNAs carried by EVs in the development of pregnancy complications. These include miR-210 and miR-136-5p for pre-eclampsia and gestational diabetes mellitus, miR-155, miR-26b-5p, miR-181a-5p, miR-495 and miR-374c for pre-eclampsia and preterm birth. The following miRNAs have been identified as potential biomarkers for preterm birth and gestational diabetes mellitus: miR-197-3p and miR-520h, miR-1323, miR-342-3p, miR-132-3p, miR-182-3p, miR-517-3p, miR-222-3p, miR-16-5p and miR-126-3p. Additionally, miR-127-3p has been linked to foetal growth restriction and preterm birth. Nevertheless, it would be premature to propose that EVs can be employed as biomarkers for pregnancy complications. Further research and the accumulation of results obtained using the methods proposed in the MISEV2023 guidelines will enable a definitive conclusion to be reached.

Although circulating microRNAs (miRNAs) in maternal blood may play an important role in regulation of pregnancy progression and serve as non-invasive biomarkers for different gestation complications, little is known about their profile in blood during normally developing pregnancy. In this study we evaluated the miRNA profiles in paired plasma and serum samples from pregnant women without health or gestational abnormalities at three time points using high-throughput sequencing technology. Sequencing revealed that the percentage of miRNA reads in plasma and serum decreased by a third compared to first and second trimesters. We found two miRNAs in plasma (hsa-miR-7853-5p and hsa-miR-200c-3p) and 10 miRNAs in serum (hsa-miR-203a-5p, hsa-miR-495-3p, hsa-miR-4435, hsa-miR-340-5p, hsa-miR-4417, hsa-miR-1266-5p, hsa-miR-4494, hsa-miR-134-3p, hsa-miR-5008-5p, and hsa-miR-6756-5p), that exhibit level changes during pregnancy (p-value adjusted < 0.05). In addition, we observed differences for 36 miRNAs between plasma and serum (p-value adjusted < 0.05), which should be taken into consideration when comparing the results between studies performed using different biosample types. The results were verified by analysis of three miRNAs using qRT-PCR (p < 0.05). The present study confirms that the circulating miRNA profile in blood changes during gestation. Our results set the basis for further investigation of molecular mechanisms, involved in regulation of pregnancy, and the search for biomarkers of gestation abnormalities.

Background: Pre-eclampsia (PE) is a serious condition affecting 2–8% of pregnancies worldwide, leading to high maternal and fetal morbidity and mortality. MicroRNAs (miRNAs), small non-coding RNA molecules, have emerged as potential biomarkers for various pregnancy-related pathologies, including PE. MiRNAs in plasma and serum have been extensively studied, but urinary miRNAs remain underexplored, especially during early pregnancy. This study aimed to investigate the urinary miRNA expression profiles in women with pre-eclampsia during the first and second trimesters. Materials and Methods: A prospective study was conducted using 48 urine samples from 24 pregnant women (n = 12 pre-eclampsia and n = 12 controls). Urine samples were collected in the first (9–13 weeks) and second (22–24 weeks) trimesters. MiRNA isolation, library preparation, and high-throughput sequencing were performed, followed by differential expression and enrichment analyses. Results: In the first trimester, five miRNAs were dysregulated in PE in comparison with the control group (hsa-miR-184, hsa-miR-203a-3p, hsa-miR-205-5p, hsa-miR-223-3p—downregulated; hsa-miR-1-3p—upregulated). In the second trimester, hsa-miR-205-5p and hsa-miR-223-3p were downregulated, and hsa-miR-9-5p, hsa-miR-1-3p, and hsa-miR-206 were upregulated. Conclusions: Our study identified differentially expressed miRNAs in the urine of pre-eclamptic patients during early pregnancy. These findings suggest that specific urinary miRNAs could serve as non-invasive biomarkers for the early detection and risk assessment of pre-eclampsia. The changes in the level of differential expression of miRNAs during gestation highlight their role in the progression of PE. Further research and validation with a larger cohort are needed to explore their clinical potential for improving maternal and fetal outcomes through early intervention.

Background: Potocki-Lupski syndrome (PTLS, OMIM # 610883) is a rare genetic developmental disorder resulting from a partial heterozygous microduplication at chromosome 17p11.2. The condition is characterized by a wide variability of clinical expression, which can make its clinical and molecular diagnosis challenging. Case presentation: We report here a family (mother and her two children) diagnosed with PTLS. When examining children, neurological and psychological (neuropsychiatric) manifestations (speech delay, mild mental retardation), motor disorders, craniofacial dysmorphism (microcephaly, dolichocephaly, triangular face, wide bulging forehead, long chin, antimongoloid slant, "elfin" ears) were revealed. The suspected clinical diagnosis was confirmed by MLPA and CMA molecular genetic testing which revealed the presence of a segmental aneusomy; microduplication in the 17p11.2 region. Conclusions: Children with PTLS can have a clinically recognizable and specific phenotype: craniofacial dysmorphism, motor and neurological manifestations, which may implicate a possible genetic disease to the attending physician. Moreover, each child with this syndrome is unique and may have a different clinical picture. The management of such patients requires a multidisciplinary team approach, including medical genetic counseling.