Significance of Pregnancy-Associated Plasma Protein-A Combined with Four-Dimensional Umbilical Artery Doppler in Fetal Growth Restriction: A Case-Control Study

Objective: This study aimed to evaluate the predictive value of combining first-trimester pregnancy-associated plasma protein-A (PAPP-A) with second-trimester four-dimensional umbilical artery Doppler ultrasound for fetal growth restriction (FGR). Methods: This retrospective study was conducted at Lu’an People’s Hospital of Anhui Province. We included pregnant women who delivered at the hospital between January 2022 and May 2024. The FGR group comprised 34 women with severe FGR, while the control group consisted of 36 women with normal fetal growth. Maternal serum PAPP-A levels were measured from first-trimester samples (11– 13⁺ 6 weeks). Four-dimensional color Doppler ultrasound was used in the second trimester (22– 30 weeks) to measure umbilical artery pulsatility index (PI), resistance index (RI), and systolic-to-diastolic (S/D) ratio. The predictive value of these parameters, both separately and in combination, was evaluated. Results: The FGR group had significantly lower fetal weight and PAPP-A levels than those of the control group (P < 0.05). The gestational age at delivery was significantly shorter in the FGR group compared to the control group (36.19 ± 1.98 vs 38.89 ± 1.47 weeks; P < 0.05). The PI, S/D, and RI in four-dimensional color Doppler ultrasound were higher in the FGR group than those in the control group (P < 0.05). Furthermore, PAPP-A and four-dimensional color Doppler ultrasound separately showed poor predictive value for FGR, without statistically significant difference. The combined use of PAPP-A and four-dimensional ultrasound parameters demonstrated superior predictive performance, with an AUC of 0.917 (95% CI: 0.86– 0.97), significantly higher than individual parameters (P < 0.05). Conclusion: The combination of first-trimester PAPP-A and second-trimester umbilical artery Doppler parameters shows high accuracy in identifying FGR, offering a clinically valuable assessment strategy. Keywords: PAPP-A, four-dimensional ultrasound, joint diagnosis, fetal growth restriction