Elastography and Metalloproteinases in Patients at High Risk of Preterm Labor

Abstract

Preterm birth (PTB) is the leading cause of perinatal morbidity and mortality. Its etiopathology is multifactorial; therefore, many of the tests contain the assessment of the biochemical factors and ultrasound evaluation of the cervix in patients at risk of preterm delivery. The study aimed at evaluating the socioeconomic data, ultrasound examinations with elastography, plasma concentrations of MMP-8 and MMP-9 metalloproteinases, and vaginal secretions in the control group as well as patients with threatened preterm delivery (high-risk patients). The study included 88 patients hospitalized in the Department of Obstetrics and Pregnancy Pathology, SPSK 1, in Lublin. Patients were qualified to the study group (50) with a transvaginal ultrasonography of cervical length (CL) ≤ 25 mm. The control group (38) were patients with a physiological course of pregnancy with CL > 25 mm. In the study group, the median length of the cervix was 17.49 mm. Elastographic parameters: strain and ratio were 0.20 and 0.83. In the control group, the median length of the cervix was 34.73 mm, while the strain and ratio were 0.20 and 1.23. In the study group, the concentration of MMP-8 in the serum and secretions of the cervix was on average 74.17 and 155.46 ng/mL, but in the control group, it was significantly lower, on average 58.49 and 94.19 ng/mL. The concentration of MMP-9 in both groups was on the same level. Evaluation of the cervical length and measurement of MMP-8 concentration are the methods of predicting preterm delivery in high-risk patients. The use of static elastography did not meet the criteria of a PTB marker.

Research Progress on the Relationship between Matrix Metalloproteinases and Preterm Birth

“…In the study by Dymanowska Dyjak, I et al [31], it was found that the concentration of MMP8 in serum and cervical secretions was significantly increased in preterm delivery. Timokhina, E et al [22] proposed that MMP2 and MMP9 are involved in the invasion of maternal blood vessels by cytotrophoblasts and the remodeling process of placental and uterine arteries.…”

“…But there are also studies indicating low expression of MMP9 on the membranes of preterm infants with intact membranes [33]. Pereza, N et al [29] did not find a relationship between MMP1 and MMP9 and preterm delivery with intact membranes, while Dymanowska Dyjak, I et al [31] found no differences in the serum and cervical secretion levels of MMP9 between preterm delivery and full-term delivery.…”

Preterm Labor, a Syndrome Attributed to the Combination of External and Internal Factors

“…Maternal age (<18 years, or >40 years), ethnicity (Black race), body mass index (<19 kg/m 2 ), smoking, stress (depression, anxiety), heavy physical labor, education, poverty, and other social factors have all been reported to be associated with sPTL. 34,35 The intrinsic factors like maternal genetic variations, immune response, obstetric factors (such as prior preterm delivery, uterine curettage, cervical factors, multiple gestations, and adverse outcome of previous term pregnancy 33 ) may also increase the risk of sPTL. Moreover, some diseases or disorders during pregnancy, such as kidney dysfunction, 36 renovascular disease, 37 cesarean section at term, 38 history of surgery for endometriosis 39 or cervical intraepithelial neoplasia, 40 were all associated with an increased risk of sPTL.…”

“…Maternal age (<18 years, or >40 years), ethnicity (Black race), body mass index (<19 kg/m 2 ), smoking, stress (depression, anxiety), heavy physical labor, education, poverty, and other social factors have all been reported to be associated with sPTL 34,35 . The intrinsic factors like maternal genetic variations, immune response, obstetric factors (such as prior preterm delivery, uterine curettage, cervical factors, multiple gestations, and adverse outcome of previous term pregnancy 33 ) may also increase the risk of sPTL.…”