The effect of vaginal infection on preterm delivery with and without cervical cerclage

To determine the risk of preterm delivery (PTD) in patients with cervical cerclage complicated by vaginal infection. This was a retrospective study using the California Office of Statewide Health Planning and Development (OSHPD) Linked Birth File from 2007-2012. There were 3,186,553 births registered during this time period. Multiple gestation and birth records without linked ICD-9-CM hospital discharge data were excluded. Patients with gonorrhea (GC) and chlamydia (CT) infections were identified on birth records. Bacteria vaginosis (BV) were identified by ICD-9 codes and in the absence of GC or CT infection. Cervical cerclage placement were identified by ICD-9 codes. The outcomes of interest included preterm delivery (PTD) before 37 and 34 weeks. The risk of preterm delivery associated with each type of infection was estimated using logistic regression using no infection (NI) as the baseline group. The regression models were adjusted for available confounders. The analysis was stratified by cerclage placement during pregnancy. In this cohort of 3,7074,055 births, 8,932 had GC infection, 6,822 had CT infection and 2,113 had BV. In the cohort with cerclage placement, the rate of PTD before 34 weeks was 7.0% without vaginal infection. In comparison the rate of PTD was highest with GC infection (20.5%, aOR: 3.43 [2.80, 4.21]. In the cohort without cerclage placement, the rate of PTD before 34 weeks was 3.5% without vaginal infection. In this stratum, the rate of PTD was highest with BV (20.1%, aOR: 6.89 [6.20, 7.67]). This pattern was similar for PTD < 37 weeks (Table). In patients who received cervical cerclage, GC and CT infections were associated with higher risk of PTD. In patients who did not receive cervical cerclage, BV infection was associated with the highest risk of infection.