Bacterial culture positivity in placental basal plate tissue and associated factors among women with spontaneous preterm births at Mubende Regional Referral Hospital, Uganda: A cross-sectional study

Aerobic bacterial culture positivity in placental basal plate tissue and its associated maternal factors remain poorly described in Uganda. This study estimated the prevalence of culture positivity and identified associated factors among women with spontaneous preterm births at Mubende Regional Referral Hospital. We conducted a hospital-based analytical cross-sectional study among 383 women between 15 May and 15 September 2025. Placental basal plate tissue specimens were collected aseptically immediately after delivery and processed for aerobic bacterial culture. Sociodemographic, obstetric and clinical data were obtained using interviewer-administered questionnaires and medical record review. Associations were examined using multivariable logistic regression and reported as adjusted odds ratios (aORs) with 95% confidence intervals (CIs). Statistical significance was set at p < 0.05. Positive cultures were identified in 159 women, giving a prevalence of 41.5% (95% CI: 36.5-46.6). Culture positivity was associated with fever (aOR = 11.32, 95% CI: 4.89-26.19), abdominal pain or uterine tenderness (aOR = 9.13, 95% CI: 4.37-19.08), membrane rupture lasting more than 24 hours (aOR = 5.93, 95% CI: 2.08-16.89), HIV infection (aOR = 4.23, 95% CI: 1.21-14.74), urinary tract infection during pregnancy (aOR = 4.20, 95% CI: 2.13-8.27), foul-smelling vaginal discharge (aOR = 3.22, 95% CI: 1.48-6.97), traditional herb use (aOR = 2.19, 95% CI: 1.16-4.13) and no formal education (aOR = 6.97, 95% CI: 1.50-32.46). Earlier gestational age, prolonged labour and primary education were also associated with culture positivity. Positive aerobic placental basal plate cultures were common in this population. These findings support improved recognition and management of maternal infection during antenatal and intrapartum care. However, culture positivity alone cannot distinguish invasive infection from colonization or contamination, and prospective studies are needed to clarify temporal and causal relationships.