Value of ultrasound in the prediction of spontaneous preterm birth: a literature review

Preterm birth (PTB) is the leading cause of neonatal and infant morbidity and mortality. This review summarizes current advances in ultrasound (US) for the prediction of spontaneous PTB. Special attention is paid to the methodology of transvaginal cervicometry, as well as other US features such as intra-amniotic "sludge," the uterocervical angle, the endocervix, fetal membrane assessment, elastography, and fetal response markers. The review also emphasizes the necessity of developing standardized protocols and performing validation studies to improve the reproducibility and clinical efficacy of US parameters used to predict spontaneous PTB. To date, it has been established that ultrasound cervicometry performed between 15 and 24 weeks of gestation effectively predicts extremely early PTB due to cervical insufficiency (CI); however, these standards of examination are often not followed in routine clinical practice. The assessment of elastography paremeters, the uterocervical angle, and the glandular index as predictors of CI-related PTB remains controversial, as does the assessment of fetal membranes, the presence of “sludge”, and fetal organ evaluation as predictors of infectious-related PTB. Although these markers hold certain potential for risk stratification, their prognostic value does not exceed that of transvaginal cervicometry, necessitating the development of models based on multifactorial analysis. Conclusion. Given the multi-etiological nature of the PTB syndrome, further research is required to identify independent, highly specific ultrasound predictors based on the probable etiology and their combination with other clinical and laboratory markers within multifactorial prognostic models. This will allow for timely and differentiated prophylaxis of spontaneous preterm birth in high-risk patients and, if necessary, facilitate patient triage to specialized centers capable of providing high-tech care for low-birth-weight preterm neonates.