Detection of growth-restricted fetuses in preeclampsia: a case-control study

Abstract

Objective: To determine the diagnostic accuracy of detecting growth-restricted fetuses in women with and without preeclampsia. Methods: Over 2 years, parturients with reliable gestational ages, preeclampsia, and sonographic estimates of birth weights were matched (1:1) for gestational age with women without preeclampsia. Paired and unpaired t tests were used; P < .05 was significant. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. Results: Two hundred eighty-seven preeclamptic women were identified and matched. In each group, mean (± standard deviation [SD]) gestational age was 34.9 ± 4.2 weeks, and 166 (57.8%) infants were born preterm. Fetal growth restriction (FGR) was significantly more common among women with preeclampsia (14.9%) than among controls (5.6%; OR 2.98, 95% CI 1.64, 5.44). The percentage of sonographic estimates within 10% of actual birth weight (57.5% versus 53.6%) was similar in the two groups (OR 1.16; 95% CI 0.84,1.62). Compared with normal growth, the mean (± SD) standardized absolute error was significantly higher among those with FGR regardless of group (preeclampsia 109 ± 100 versus 158 ± 152 g/kg; P = .009; control 117 ± 103 versus 233 ± 206 g/kg; P < .001). Fetal growth restriction was detected more commonly among preeclamptic women than among controls (11.6% versus 0%; OR 4.74 95% CI 0.25, 90.31). The sensitivity and positive predictive value of FGR detection were 10% and 50%, respectively, among women with preeclampsia and 0% each among controls. Conclusion: Although FGR was detected more frequently in fetuses of women with preeclampsia than in those of controls, the ability to predict it with sonography remained poor.