Placental Characteristics on Second-Trimester Ultrasound and Their Association with Maternal and Fetal Outcomes

Abstract

Background: Many adverse maternal and fetal outcomes such as preeclampsia, fetal growth restriction (FGR), small for gestational age (SGA) and preterm premature rupture of the membrane (PPROM), are thought to be related to placental characteristics. Thus, several of these adverse outcomes may be detected through ultrasound, potentially allowing for preventive interventions. This study aimed to investigate the relationship between placental characteristics on second-trimester ultrasound and fetal outcomes. Methods: This observational study was conducted on 200 pregnant women. The inclusion criteria were women with a singleton pregnancy and a gestational age between 14+0 and 27+6. All participants underwent ultrasound in their second-trimester and placental characteristics, including location, size, echogenicity, calcification grade and thickness, were recorded. All mothers were followed until delivery and maternal and fetal outcomes such as preeclampsia, FGR, SGA and PPROM were documented. Findings: Data from 195 patients were analyzed. The mean age of participants was 31.25 ± 5.32 years. The mean gestational age at delivery was 37.91 ± 2.19 weeks (range: 24–41), and the mean gestational age at the time of ultrasound was 22.9 ± 3.89 weeks (range: 14+0–27+6). The mean placental thickness was 23.53 ± 6.22 mm (range: 14–67.6), and the mean placental area (length × width) was 11,130.09 ± 7,479.55 mm² (range: 10,008–93,021.6). Placental location was posterior in 84 cases (43.1), anterior in 104 cases (53.3), and fundal in 7 cases (3.6). Only 3 cases (1.5) had heterogeneous echogenicity. Regarding maternal and fetal outcomes, out of all participants 16 (8.2) cases had FGR, 2 (1) cases had IUFD, 19 (9.7) cases had SGA, 3 (1.5) cases had abruption, 6 (3.1) cases had PPROM, 8 (4.1) cases had OHA and 15 (7.6) cases had preeclampsia. Conclusion: Our data indicate a strong association between placental size and thickness and the occurrence of FGR and SGA. Further studies with larger sample sizes are recommended. © 2026, Isfahan University of Medical Sciences(IUMS). All rights reserved.