Comprehensive assessment of risk factors as a method for predicting prelabour rupture of membranes

BACKGROUND: Prelabour rupture of the membranes (PROM) is a common obstetric pathology, the incidence of which reaches 20%. There is evidence that PROM is the main risk factor not only for abnormal labor, but also for postpartum hypotonic bleeding. Meanwhile, the etiology and pathogenesis of this complication have not been finally determined until now.

AIM: The aim of this study was to create a model that allows for predicting PROM, based on a comprehensive assessment of risk factors.

MATERIALS AND METHODS: Based on the data collected in the Regional Clinical Hospital Perinatal Center, Chita, Russia in 2018-2021, the prospective analysis of 213 cases of labor was carried out. The total sample was divided into two study groups: group 1 included 142 cases of labor with timely rupture of membranes; group 2 included 71 cases of labor, complicated by PROM. The groups were comparable in terms of nationality, age, material and social living conditions of women, frequency of genital pathology, gestational age and gender distribution of newborns. On the eve of labor (1-2 days), all patients underwent a general clinical examination and clarification of the anamnesis. Ultrasound examination was carried out both the day before and during labor in order to clarify fetal position. Statistical processing of the results was carried out using the IBM SPSS Statistics Version 25.0 program.

RESULTS: Risk factors for PROM are: the presence of posterior view of the occipital presentation (RR = 2.67 (95 % CI 1.13-6.31), p = 0.02) and varicose veins (RR = 3.2 (95 % CI 1.09-9.43), p = 0.04), distantia cristarum more than 28.5 cm (RR = 1.99 (95 % CI 1.12-3.54), p = 0.02), distantia trochanterica more than 30.5 cm (RR = 2.15 (95 % CI 1.09-4.23), p = 0.03), and conjugata externa more than 20.5 cm (RR = 1.84 (95 % CI 1.01-3.37), p = 0.046). Oligohydroamnion is a protective factor in relation to PROM (RR = 0.31 (95 % CI 0.11-0.85), p = 0.02). This predictive model, which takes into account such factors as the type of fetal head presentation, the presence of oligohydramnios and varicose veins, and the size of distantia cristarum, allows for predicting PROM with much effect.

CONCLUSIONS: The comprehensive assessment of risk factors, despite its simplicity and availability, allows for predicting the timeliness of rupture of the membranes with an accuracy of 71.0%. Application of the developed model makes it possible to identify a risk group subject to preventive preinduction, which in the future will help to reduce the frequency of abnormal labor and associated complications.