Ultrasound parameters and anamnestic findings as potential predictors of fetal hypoxia among late fetal growth restriction requiring preterm delivery

BACKGROUND: When the hypoxia of fetus with growth restriction is diagnosed, the choice of the timing and method of delivery is an important aspect to improve perinatal outcomes. Delphi (2016) consensus criteria are relevant in identifying and diagnosing “fetal growth restriction.” However, there are still no predictors with which it is possible to predict fetal deterioration requiring preterm delivery. AIM: The aim of this study was to evaluate the association of ultrasound parameters, anamnesis factors and hypoxia requiring preterm delivery among late-onset fetal growth restriction. MATERIALS AND METHODS: This cohort study was performed at the Perinatal Center, the Arkhangelsk Regional Clinical Hospital (Arkhangelsk, Russia) from 2018 to 2022 and included 314 women with suspected fetal growth restriction who met the inclusion criteria. The association between preterm birth due to fetal hypoxia and ultrasound, clinical and history-based parameters was assessed by multivariable Poisson regression analysis with robust error variance. Unadjusted and adjusted relative risks with 95 % confidence intervals were calculated. The most parsimonious model was created by backward elimination of variables using the Wald test with a significance level of 0.05. RESULTS: Late-onset fetal growth restriction was detected in 111 (35.4%) cases, among which premature birth occurred in 54 (48.6%) women due to fetal hypoxia. The most parsimonious model included two predictors. Umbilicocerebral ratio abnormalities (relative risk 1.59; 95% confidence interval 1.19–2.11) and a history of fetal growth restriction pregnancy (relative risk 1.53; 95% confidence interval 1.07–2.19) were positively associated with an increased risk of fetal hypoxia requiring preterm delivery. CONCLUSIONS: Estimation of the umbilicocerebral ratio abnormalities according to Doppler ultrasound examination data and the history of fetal growth restriction may have prognostic value to make the decision on timely delivery to improve perinatal outcomes in late fetal growth restriction. The data obtained may be used in larger multicenter studies followed by the creation of valid prognostic models with sufficient levels of sensitivity and specificity for using in the clinical practice of obstetrician-gynecologists.