RESUMO
OBJECTIVE: To evaluate the ability of second-trimester placental volume and vascular indices to predict small-for-gestational-age (SGA) birth weight pregnancies. MATERIAL AND METHODS: Women with singleton pregnancies were prospectively evaluated at 17-20 weeks of gestation. Second-trimester placental volume and vascular indices were obtained and calculated using volume organ computer-aided analysis and three-dimensional (3D) power Doppler ultrasound. Participants were followed until delivery and their medical records were reviewed, including maternal age, parity and pregestational body weight and body height, as well as the gestational age, birth weight and gender of the fetus. RESULTS: Of the 163 women with complete follow-up, 20 gave birth to SGA and 143 to appropriate-for-gestational-age (AGA) neonates. The mean second-trimester placental volume was significantly lower in the SGA than in the AGA group (170.6 ± 49.8 vs. 213.5 ± 75.8 cm(3), p = 0.015). None of the vascular indices, including the vascularization index, flow index and vascularization flow index, differed significantly between the two groups. We also found that the optimum cutoff for placental volume at a gestational age of 17-18 weeks was 189.7 cm(3). DISCUSSION: Second-trimester placental volume was positively correlated with neonatal birth weight. Second-trimester placental volume measured on 3D ultrasound may be predictive of SGA neonates.