Raw data and.

Objective
To compare maternal and neonatal outcomes in women with a previous history of pregnancy loss and/or preterm delivery who underwent ultrasound-indicated cerclage (UIC) or history-indicated cerclage (HIC).
Methods
PubMed, Web of Science, Scopus, and Embase databases were searched for observational studies and randomized controlled trials (RCT) from inception to 30 April 2024. Eligible studies should have compared the outcomes of women with singleton pregnancies who underwent UIC or HIC. STATA version 15.0 was employed, and the analysis was done using a random effects model and unadjusted effect sizes from the included studies.
Results
Of 25 included studies (n = 3909), most (n = 18) were retrospective cohort studies. Compared to women who underwent HIC, UIC was associated with higher risk of having a preterm birth (<37 weeks of gestation) (OR 1.48, 95% CI: 1.17, 1.88; N = 15), low birth weight (<2500g) (OR 1.78, 95% CI: 1.32, 2.41; N = 6) and admission to neonatal intensive care unit (OR 1.70, 95% CI: 1.27, 2.27; N = 6,). Women with UIC also had a higher risk of chorioamnionitis (OR 2.34, 95% CI: 1.36, 4.04; N = 4). The risk of having a low APGAR score (5-minute score of less than 7), fetal death and preterm premature rupture of membrane (PPROM) was comparable among the two groups.
Conclusion
Our results demonstrate that UIC is associated with higher risks of adverse pregnancy outcomes compared to HIC. However, our evidence emanates from observational studies and is prone to biases, particularly because the findings were unadjusted for potential confounders. More clinical trials are needed to confirm our observations.
Systematic review protocol registration
PROSPERO CRD42024544181