Association of patient characteristics with preterm birth among patients with a history of preterm birth: a single-center retrospective study

Background We hypothesized that receiving cervical length screening (CLS) would be associated with a lower incidence of preterm birth (PTB) among patients with a history of PTB.Methods Patients who delivered live and stillborn infants at Baylor Scott & White Medical Center – Temple from January 1, 2023, to December 31, 2023 and had a medical history of PTB were included in the analysis. We performed a bivariate analysis between patients who did and did not have PTB. We then performed a multivariate logistic regression to determine which variables were independently associated with PTB.Results There were 2756 births during the study period, and 185 patients met inclusion criteria. Tricare versus commercial insurance (adjusted odds ratio [aOR] 3.39; 95% confidence interval [CI] 1.17–9.80; P = 0.02) and receiving CLS (aOR 2.82; 95% CI 1.37–5.81; P = 0.005) were independently associated with PTB. The c-statistic of this multivariate model was 0.68.Discussion Tricare versus commercial insurance and receiving CLS were associated with a 239% and 182% increase, respectively, in the chance of PTB. It is possible that unmeasured variables among patients who had CLS were associated with PTB.