Objective: To determine the effect and predictive value of the difference between the mean gestational diameter (mGSD) sac and crown-rump length (CRL) of the first trimester on the pregnancy outcomes of patients with recurrent spontaneous abortion (RSA).Methods: 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. They were divided into the following three groups based on the difference between the mGSD and CRL (mGSD-CRL): Group A: mGSD-CRL ≥ 10mm, 41 cases; Group B: 10mm < mGSD-CRL ≤ 15mm, 109 cases; and Group C: mGSD-CRL > 15mm, 106 cases.

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.

Inclusion Criteria:

(1) patients diagnosed with RSA based on medical history, (2) those who intend to continue the pregnancy, (3) singleton pregnancy, (4) gestational age is between 6-10 weeks, and (5) the conception for the current pregnancy was natural

Exclusion Criteria:

(1) individuals with multiple pregnancies or ectopic pregnancies, (2) conception through assisted reproductive techniques, and (3) chromosomal abnormalities in pregnant women or their partners.

the pregnant women with recurrent spontaneous abortion

The pregnant women with RSA who visited the First Affiliated Hospital of Xiamen University from January 2020 to March 2023

The IPD underlying this article can be made available on reasonable request to the corresponding author.