A nomogram for predicting the risk of fetal growth restriction in singleton pregnancies with subchorionic hematomas detected in first trimester.

Abstract

Objective: To investigate the relationship between first trimester subchorionic hematoma (SCH) and fetal growth restriction (FGR), and to develop a nomogram for predicting the risk of FGR in patients with SCH.

Methods: We conducted a retrospective cohort study from January 2021 to December 2021, involving singleton pregnancies that received routine prenatal care since the first trimester at our hospital. We excluded pregnancies loss before 20 weeks and ultimately included 1,055 individuals in the study, dividing them into two groups based on whether they were diagnosed with SCH. We compared the pregnancy outcomes in women with and without a SCH. After confirming an independent association between FGR and SCH detected in the first trimester, we conducted a subgroup analysis to identify high-risk factors for FGR among patients with SCH. Logistic regression was employed to identify risk factors for FGR in patients with SCH, and the nomogram was constructed based on the regression coefficients of relevant variables. The calibration of the prediction model was confirmed through the Hosmer-Lemeshow goodness-of-fit test (P > 0.05), and discrimination was assessed using the area under the receiver operating characteristic curve (ROC).

Results: A total of 1,055 individuals were enrolled in the study, with 504 identified with SCH during the first trimester ultrasound examination. Women with SCH had a higher likelihood of experiencing vaginal bleeding (36.5% vs. 21.8%, P < 0.001). The presence of a first trimester SCH was independently associated with FGR [adjusted odds ratio (OR) 4.30, 95% confidence interval (CI) 1.58-11.66]. Subgroup analysis of women with SCH showed that gestational age at diagnosis of SCH ≥ 7 weeks (OR 3.04, 95% CI 1.03-9.00), SCH persisting in the second trimester (OR 4.93, 95% CI 1.71-14.25), leiomyoma ≥ 4 cm (OR 17.23, 95% CI 3.78-78.56), and GDM (OR 3.42, 95% CI 1.18-9.87) were risk factors for FGR. The prediction model was developed based on these factors and presented as a nomogram. The AUC of the nomogram was 0.769 (95% CI: 0.655-0.883, P < 0.001), suggesting a good prediction capability.

Conclusions: First trimester SCH is independently associated with an increased risk of FGR, and the nomogram developed effectively predicts FGR in pregnancies with SCH.