Maternal demographics and hemodynamics for the prediction of fetal growth restriction at booking, in pregnancies at high risk for placental insufficiency.

Introduction: Fetal growth restriction (FGR) is associated with poor perinatal outcomes. Screening and prevention tools for FGR, such as uterine artery Doppler imaging and aspirin, underperform in high-risk groups, compared with general antenatal populations. There is a paucity of sensitive screening tests for the early prediction of FGR in high-risk pregnancies.

Materials And Methods: This was a prospective observational study based in a dedicated antenatal hypertension clinic at a tertiary UK hospital. We assessed maternal demographic and central hemodynamic variables as predictors for FGR in a group of women at high risk for placental insufficiency due to chronic hypertension (n = 55) or a history of hypertension in a previous pregnancy (n = 71). Outcome variables were birthweight z-score as well as development of FGR (defined as birthweight below the 5th or 3rd centile). Maternal hemodynamics were assessed using a noninvasive transthoracic bioreactance monitor (Cheetah NICOM).

Results: The mean gestation at presentation was 13.6 (range: 8.5-19.5) weeks. Sixteen women delivered babies below the 5th centile. Ten of these were below the 3rd centile. Independent predictors of birthweight z-score were body surface area, peripheral vascular resistance and white ethnicity (R(2) = 0.26, p < 0.0001). Independent predictors of FGR were maternal height and cardiac output. The area under the receiver operator characteristic curve for prediction of FGR was 0.915 (95% CI 0.859-0.972) and 0.9079 (95% CI 0.823-0.990) for FGR below the 5th and 3rd centiles, respectively.

Conclusion: In women with chronic hypertension or a history of hypertension in a previous pregnancy, maternal size and cardiac output at booking provide a sensitive screening tool for FGR.