Prenatal exposure to intra-amniotic infection with species increases the prevalence of bronchopulmonary dysplasia.

Objectives: The present study investigated the relationship between bronchopulmonary dysplasia (BPD) and intra-amniotic infection with species.

Methods: This was a single-center, retrospective cohort study. Patients with singleton pregnancies who underwent inpatient management at our department for preterm premature rupture of membranes (PPROM), preterm labor, cervical insufficiency, and asymptomatic cervical shortening at 22-33 gestational weeks were included. Amniocentesis was indicated for patients with PPROM or an elevated maternal C-reactive protein level (≥0.58 mg/dL). Patients with an amniotic fluid IL-6 concentration ≥3.0 ng/mL were diagnosed with intra-amniotic inflammation, while those with positive aerobic, anaerobic, , and spp. cultures were diagnosed with microbial invasion of the amniotic cavity (MIAC). Patients who tested positive for both intra-amniotic inflammation and MIAC were considered to have intra-amniotic infection. An umbilical vein blood IL-6 concentration >11.0 pg/mL indicated fetal inflammatory response syndrome (FIRS). The maternal inflammatory response (MIR) and fetal inflammatory response (FIR) were staged using the Amsterdam Placental Workshop Group Consensus Statement.

Results: Intra-amniotic infection with spp. was diagnosed in 37 patients, intra-amniotic infection without spp. in 28, intra-amniotic inflammation without MIAC in 58, and preterm birth without MIR/FIR and FIRS in 86 as controls. Following an adjustment for gestational age at birth, the risk of BPD was increased in patients with intra-amniotic infection with spp. (adjusted odds ratio: 10.5; 95% confidence interval: 1.55-71.2), but not in those with intra-amniotic infection without spp. or intra-amniotic inflammation without MIAC.

Conclusion: BPD was only associated with intra-amniotic infection with species.