The Journal of Practical Medicine ›› 2025, Vol. 41 ›› Issue (22): 3480-3489.doi: 10.3969/j.issn.1006-5725.2025.22.003

• Feature Reports:Reproductive Health • Previous Articles    

Construction and validation of a model for jointly predicting early pregnancy loss at 6 weeks of gestation after IVF⁃ET based on serum FGF⁃21, AMH, and NRP⁃1

Hongwei ZHANG,Nan WANG,Guoxi SHI,Junying ZHAI(),Hongli NIU,Ying WANG   

  1. Department of Reproductive,Nanyang First People's Hospital,Nanyang 473000,Henan,China
  • Received:2025-08-12 Online:2025-11-25 Published:2025-11-26
  • Contact: Junying ZHAI E-mail:zzhaijunying@163.com

Abstract:

Objective To investigate the predictive value of pre-transfer serum fibroblast growth factor 21 (FGF-21), anti-Müllerian hormone (AMH), and neuropilin-1 (NRP-1) for early pregnancy loss at 6 weeks following in vitro fertilization-embryo transfer (IVF-ET), and to establish an early predictive model based on serum biochemical markers. Methods This prospective study consecutively enrolled 322 women who achieved clinical pregnancy after IVF-ET at our center between September 2022 and September 2024. Participants were randomly divided into a modeling cohort (n = 225) and a validation cohort (n = 97) at a 7:3 ratio. According to ultrasound findings at 6 weeks of gestation, patients in the modeling cohort were classified into an early pregnancy loss group (n = 59) and an ongoing pregnancy group (n = 166). Baseline clinical characteristics and pre-transfer serum levels of FGF-21, AMH, and NRP-1 were collected. Multivariate logistic regression was applied to identify independent risk factors for early pregnancy loss and to construct a predictive model. Model discrimination, calibration, and stability were evaluated using receiver operating characteristic (ROC) curves, the Hosmer-Lemeshow goodness-of-fit test, and bootstrap resampling in both cohorts. Results Univariate analysis revealed that the FSH/LH ratio, antral follicle count, and number of retrieved oocytes were significantly associated with early pregnancy loss (P < 0.001). Compared with the ongoing pregnancy group, women with early loss showed significantly elevated pre-transfer serum FGF-21 levels, whereas AMH and NRP-1 levels were markedly reduced (P < 0.001). Multivariate logistic regression demonstrated that an FSH/LH ratio < 1.8 (OR = 1.629, P = 0.002) and higher FGF-21 levels (OR = 1.338, P = 0.002) were independent risk factors, while higher AMH (OR = 0.741, P = 0.010) and NRP-1 levels (OR = 0.874, P = 0.007) were protective. Stratified analysis indicated that among patients with FSH/LH ≥ 1.8, FGF-21 levels were significantly higher and AMH and NRP-1 levels significantly lower (all P < 0.001). Interaction analysis further suggested that the FSH/LH ratio significantly modified the associations between these biomarkers and pregnancy loss risk (P for interaction < 0.05). Specifically, in the higher FSH/LH subgroup, the risk effect of FGF-21 was amplified, while the protective effects of AMH and NRP-1 were more pronounced. The combined predictive model achieved C-indices of 0.869 (95%CI: 0.826 ~ 0.926) in the modeling cohort and 0.835 (95%CI: 0.811 ~ 0.907) in the validation cohort. Its AUC for predicting early pregnancy loss was 0.934 in the modeling cohort and 0.909 in the validation cohort, both significantly outperforming individual markers (AUCs: FGF-21 = 0.867, AMH = 0.881, NRP-1 = 0.853; Z = 2.024, 1.831; P < 0.001). Decision curve analysis showed that the model provided consistent net clinical benefit across threshold probabilities of 0.1 ~ 0.4, underscoring its clinical utility. Conclusions Elevated pre-transfer serum FGF-21 and reduced AMH and NRP-1 levels are strongly associated with early pregnancy loss at 6 weeks after IVF-ET. The predictive model developed in this study demonstrates robust accuracy and stability, offering substantial clinical application value for early risk stratification.

Key words: FGF-21, AMH, NRP-1, in vitro fertilization-embryo transfer, early pregnancy loss, predictive value

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