DOI: 10.6084/m9.figshare.26235531.v1
title: The influence of previous preterm birth with singleton pregnancy on the risk of recurrence in subsequent twin pregnancy: a meta-analysis

description: Preterm birth is a significant obstetrical concern around the globe. With this study, we aimed to determine whether a prior singleton pregnancy preterm birth increases the likelihood of preterm birth in subsequent twin pregnancies. We designed his systematic review to provide valuable information for pregnant women and obstetricians during counselling and for individuals involved in the planning of preventive strategies. We comprehensively searched the PubMed, Embase and Scopus databases to identify relevant studies published until October 2023 following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We applied a random-effects meta-analysis to the data gathered from the selected studies. Among the 460 initially identified studies, only eight met the eligibility criteria. The analysis of incidence revealed an event rate of 9.5% (95% CI, 4.4–19.5%) for a history of preterm singleton birth in the cohort of women with subsequent twin pregnancies. Subgroup analyses focused on the risk of preterm twin births (&lt;37 weeks, &lt;34 weeks and &lt;32 weeks) in women with prior preterm singleton births. Our results revealed a significantly elevated risk of subsequent preterm twin births associated with prior preterm singleton births at &lt;37 weeks (OR, 2.94; 95% CI, 1.99–4.33; <i>p</i> &lt; .001), &lt;34 weeks (OR, 1.89; 95% CI, 1.67–2.14; <i>p</i> &lt; .001) and &lt;32 weeks (OR, 2.51; 95% CI, 1.58–3.99; <i>p</i> &lt; .001), without heterogeneity in the included studies. Our systematic analysis indicates a consistent and statistically significant association between a history of preterm singleton births and preterm twin births at various gestational ages. These findings underscore the importance of the obstetric history during assessments to predict the risk of preterm births in twin pregnancies. Clinicians should monitor pregnancies with a history of preterm singleton births, as targeted interventions and improved prenatal care can mitigate the risk of preterm birth during twin pregnancies. Preterm birth, a global concern, prompted a study examining whether a prior preterm singleton birth raises the risk of preterm birth in subsequent twin pregnancies. Conducting a systematic review of 460 studies, only eight met the eligibility criteria. The meta-analysis revealed a 9.5% incidence of preterm singleton births in subsequent twin pregnancies. Further analysis demonstrated a significantly elevated risk of preterm twin births at &lt;32 weeks for those with a history of preterm singleton births. The study concludes that a consistent and statistically significant association exists between prior preterm singleton births and increased preterm twin birth risk at various gestational ages. This underscores the importance of considering obstetric history in assessing preterm birth risk in twin pregnancies. Clinicians are advised to closely monitor pregnancies with a history of preterm singleton births for interventions targeted and improved prenatal care.