Difference Between Mean Gestational Sac Diameter and Crown-rump Length as a Marker of First-trimester Pregnancy Outcome in Patients With Recurrent Spontaneous Abortion

Study question: Can the difference between mean gestational sac diameter and crown-rump length (mGSD-CRL) act as a marker of first-trimester pregnancy outcome in patients with recurrent spontaneous abortion (RSA)? Summary answer: In patients with RSA, mGSD-CRL acts as an independent risk factor affecting pregnancy outcomes, as it can effectively predict the early pregnancy outcomes of patients with RSA. What is known already: RSA refers to the occurrence of two or more consecutive miscarriages with the same partner before reaching 28 weeks of gestation, which causes considerable physical and psychological distress to the patients. Therefore, predicting the outcome of subsequent pregnancies in patients with RSA is important. Recent studies have reported a smaller mGSD-CRL difference in association with a higher rate of spontaneous abortion. In addition, thrombophilia-induced RSA has garnered increasing research attention as it is an important cause of early and late miscarriages. Study design, size, duration: This is a retrospective cohort study. In total, 256 pregnant women at 6-10 weeks of gestation and with RSA who visited our hospital from January 2020 to March 2023 were included in the study. 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.