Hypertensive disorders in pregnancies with early-onset fetal growth restriction: a retrospective cohort study

Early onset fetal growth restriction (FGR) shares pathophysiologic origins and may precede the development of Hypertensive Disorder of Pregnancy (HDP). The aim of this study was to evaluate risk factors associated with the development of HDP in individuals with early onset FGR.

This retrospective cohort included all consecutive patients who presented to our tertiary, university-affiliated medical center between 2011 and 2024 for suspected early-onset FGR, defined as onset before 32 weeks of gestation. Maternal and pregnancy information retrieved from hospital records included maternal age, BMI, smoking history, parity, gestational age (GA) at diagnosis, chronic hypertension, maternal cardiac disease, pre- or gestational diabetes, thrombophilia, chronic renal disease, history of major pregnancy complications, mode of conception, number of fetuses, premature contractions (PMC), ultrasound (US) measured abdominal circumference (AC), US measured estimated fetal weight (EFW), umbilical artery Doppler PI (UAPI) and middle cerebral artery Doppler PI (MCAPI). AC and EFW were classified as <5% and <3% respectively based on local population growth charts. UAPI and MCAPI percentiles were calculated per specific GA. We present maternal and pregnancy characteristics stratified by the development of HDP and investigated the association of these variables with development of HDP using univariate and multivariable logistic regression. The analyses were performed using R statistical software, and statistical significance was defined as p < 0.05.

During the study period 774 pregnant individuals were presented for suspected early-onset FGR. Among them, 79 (10.2%) subsequently developed HDP later in pregnancy. Using multivariate analysis UAPI above the 95^th percentile (OR 3.35, CI 1.55-7.20, p < 0.01), GA 24-28 weeks at diagnosis (OR 2.54, CI 1.20-5.36, p = 0.01) and AC below the 5^th percentile (OR 2.31, CI 1.10-4.86, p = 0.02), were significantly associated with the subsequent development of HDP.

Among pregnancies with suspected early-onset FGR, an elevated UAPI (>95th percentile) was the strongest predictor of developing HDP. Additional risk factors included earlier gestational age at FGR diagnosis and an AC below the 5th percentile. Women with these risk factors warrant intensified maternal surveillance. Future studies integrating these clinical predictors with circulating angiogenic biomarkers may further refine risk stratification.