Table 1. Demographic and Clinical Characteristics of the Study Population According to the Presence or Absence of Histologic Chorioamnionitis.
| Histologic chorioamnionitis | p value | ||
|---|---|---|---|
| Presence (n=74) | Absence (n=72) | ||
| Maternal age (yrs) | 32.2±3.6 | 31.4±4.6 | 0.221 |
| Nulliparity | 37% (27/74) | 49% (35/72) | 0.138 |
| Previous spontaneous preterm birth (<37 wks) | 5% (4/74) | 10% (7/72) | 0.323 |
| Gestational age at assessment (wks) | 29.1±3.3 | 31.2±2.9 | <0.001 |
| Gestational age at delivery (wks) | 30.3±3.3 | 32.6±2.4 | <0.001 |
| Cervical length by ultrasound (mm) | 22.2±12.4 | 23.9±11.1 | 0.372 |
| Sampling-to-delivery interval [hrs, median (95% Cl)] | 123 (70–176) | 253 (105–401) | 0.257* |
| Maternal blood WBC count (cells/mm3) | 12037±3623 | 10434±3516 | <0.01 |
| Serum C-reactive protein (mg/L) | 12.7±1.68 | 4.8±5.2 | <0.001 |
| Amniotic fluid IL-6 (ng/mL) | 15.0±23.2 | 2.8±6.7 | <0.001 |
| Amniotic fluid WBC count (cells/mm3) | 1790±8426 | 311±1429 | <0.001 |
| Positive amniotic fluid cultures | 46% (34/74) | 24% (17/72) | <0.01 |
| Funisitis | 47% (35/74) | 0% (0/72) | <0.001 |
| Clinical chorioamnionitis | 14% (10/74) | 4% (3/72) | 0.047 |
| Use of antibiotics | 96% (71/74) | 94% (68/72) | 0.671 |
| Use of antenatal corticosteroids | 81% (60/74) | 86% (62/72) | 0.412 |
| Composite neonatal morbidity† | 49% (33/68) | 28% (20/71) | <0.05 |
| Early-onset neonatal sepsis | 7% (5/68) | 10% (7/71) | 0.599 |
| Respiratory distress syndrome | 32% (22/68) | 18% (13/71) | 0.057 |
| Bronchopulmonary dysplasia | 25% (17/68) | 7% (5/71) | <0.005 |
| Necrotizing enterocolitis | 4% (3/68) | 0% (0/71) | 0.114 |
| Periventricular leukomalacia | 9% (6/68) | 11% (8/71) | 0.632 |
| Neonatal mortality† | 1% (1/68) | 1% (1/71) | 1.000 |
| Birth weight (g) | 1584±518 | 1991±510 | <0.001 |
CI, confidence interval; WBC, white blood cell; IL-6, interleukin-6.
Values are presented as the mean±standard deviation or % (n) unless otherwise indicated.
*Log-rank test, †Seven infants who were not actively resuscitated at birth due to extremely low gestational age (less than 23.4 weeks) were excluded.