Difference between mean gestational sac diameter and crown rump length predicts pregnancy outcome in patients with recurrent spontaneous abortion

Knowing the predictors of pregnancy outcomes in patients with recurrent spontaneous abortion (RSA) is extremely critical. Accordingly, we aimed to determine the effects of the difference between mean gestational sac diameter and crown-rump length (mGSD-CRL) on the pregnancy outcomes in patients with RSA at 6-10 gestational weeks, as well as to explore its significance in predicting the pregnancy outcomes of patients with RSA. This retrospective cohort study included 256 pregnant women at 6-10 weeks of gestation and with RSA who had visited our hospital from January 2020 to March 2023. The patients were allocated to three groups based on the mGSD-CRL difference: Group A: mGSD-CRL ≤ 10 mm, Group B: 10 mm < mGSD-CRL ≤ 15 mm, and Group C: mGSD-CRL > 15 mm. The pregnancy failure rate in Group A was 22%, which was higher than those that in Group B (5.5%) and Group C (9.4%), with statistically significant differences (P < 0.05). Binary logistic regression analysis revealed that the mGSD (odd ratio [OR] = 1.14, 95% confidence interval [CI] = 1.06-1.23, P = 0.001), the CRL (OR = 1.16, 95% CI = 1.05-1.28, P = 0.004), and mGSD-CRL (OR = 1.12, 95% CI = 1.01-1.24, P = 0.026) were independent risk factors affecting the pregnancy outcome of patients with RSA. However, the uterine artery peak systolic value to end-diastolic value (UtA-S/D), D-dimer (DD), adenosine diphosphate (ADP), and arachidonic acid (AA) were not related (P > 0.05). The area under the receiver operator characteristic (ROC) curve of mGSD-CRL at 6-10 weeks of pregnancy was 0.566, with a cutoff value of 9.50 mm. The sensitivity and specificity were 90% and 36%, respectively. Compared with their prediction value, the combined prediction of mGSD-CRL, mGSD, and CRL exhibited a higher value (AUC = 0.718) in predicting pregnancy outcomes. A weak negative correlation was detected between ADP and mGSD-CRL difference (r = - 0.165, P = 0.025). In patients with RSA, mGSD-CRL acts as an independent risk factor affecting pregnancy outcomes, thereby effectively predicting the early pregnancy outcomes of patients with RSA. Thus, a low mGSD-CRL difference signifies the heightened probability of miscarriage, thereby urgently requiring clinicians to pay timely attention. Trial registration: The study is registered at ClinincalTrails.gov (Trial registration number: NCT06081556, October 13, 2023).