Fetal breathing movements within 24 hours of delivery in prematurity are related to histologic and clinical evidence of amnionitis.

Our objective was to determine the association of fetal breathing movements (FBM) within 24 hr of delivery, with the clinical diagnosis of chorioamnionitis and histologic evidence of severe acute amnionitis and umbilical-chorionic vasculitis in women delivering at < 32 weeks' gestation. We performed a cohort study of patients with singleton gestations delivered at < 32 weeks' following preterm labor with intact membranes and sonographically assessed biophysical profile within 24 hr of delivery (n = 111). Patients with FBM were compared with those without FBM, with regard to prevalence of clinical chorioamnionitis (CA) and histologic diagnosis of acute amnionitis and umbilical vasculitis. Maternal and neonatal charts were reviewed and the diagnosis of clinical CA made by previously established criteria. Histologic presence and extent of acute intrauterine inflammation was assessed and scored by a single pathologist blinded to clinical information. Results are presented as chi 2 values and odds ratios with 95% confidence intervals. Of the patients included in the study, FBM were absent in 56 and present in 55. The prevalence of CA was 13% (15 of 111), severe acute amnionitis 34% (38 of 111), and severe umbilical vasculitis 23% (26 of 111). Severe umbilical vasculitis was significantly less frequent in cases with FBM as compared to cases without FBM (15% [8 of 55] vs. 32% [18 of 56], p = 0.049). However, the difference in rate of CA (22% [12 of 55] vs. 34% [19 of 56], p = 0.22) and histologic severe amnionitis (29% [16 of 55] vs. 39% [22 of 56], p = 0.4) between cases with and without FBM was not significant. In the presence of preterm labor with intact membranes, absence of FBM had sensitivities of 73 and 72%, and specificities of 54 and 56% in the prediction of CA and histologic evidence of umbilical vasculitis, respectively. We conclude that absence of FBM is associated with histologic evidence of fetal inflammation in intrauterine infection in patients with preterm labor and intact membranes delivering at < 32 weeks. However, the low positive predictive value of absent FBM in predicting fetal inflammation in intrauterine infection should discourage the guidance of clinical management in patients < 32 weeks' gestation with preterm labor and intact membranes.