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

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. (C) 1999 by The American College of Obstetricians and Gynecologists.