The importance of intra-amniotic inflammation in the subsequent development of atypical chronic lung disease

Figures & data

Table I.  Comparison of the clinical characteristics of the study population between cases with atypical CLD and those with CLD with RDS.

	Atypical CLD n = 39	CLD with RDS n = 33	p-value
Maternal age [years, median (range)]	32 (24–43)	32 (22–43)	NS
Maternal parity (nullipara) (%)	19 (48.7)	13 (39.4)	NS
Gestational age at delivery [weeks, median (range)]	28.0 (24.0–31.0)	27.3 (24.0–31.6)	NS
Birth weight [g, median (range)]	900 (470–2100)	970 (430–2350)	NS
Etiology of delivery (%)
Preterm labor	15 (38.5)	14 (42.4)
Premature rupture of membrane	15 (38.5)	6 (18.2)
Hypertensive disorders in pregnancy	4 (10.3)	9 (27.3)
Other	5 (12.8)	4 (12.1)
Cesarean delivery (%)	22 (56.4)	22 (66.7)	NS
Antenatal steroid use (%)	31 (79.5)	26 (78.8)	NS
Male sex (%)	27 (69.2)	16 (48.5)	NS
1-min Apgar score <7 (%)	33 (84.6)	33 (100)	0.028
5-min Apgar score <7 (%)	23 (59.0)	27 (81.8)	0.036
Cord arterial blood pH <7.15 (%)	3/29 (10.3)	2/29 (6.9)	NS
Ventilation duration (days, median)	43.0	49.0	NS
O2 duration (days, median)	67.0	67.0	NS
Congenital pneumonia (%)	1 (2.6)	3 (9.1)	NS
Intraventricular hemorrhage(≥grade II) (%)	7 (17.9)	9 (27.3)	NS
Periventricular leukomalacia (%)	3 (7.7)	1 (3.0)	NS
Necrotizing enterocolitis (%)	7 (17.9)	3 (9.1)	NS
Congenital sepsis (suspected or proven) (%)	12 (30.8)	10 (30.3)	NS
Congenital sepsis (proven) (%)	1 (2.6)	2 (6.1)	NS
Patent ductus arteriosus (%)	17 (43.6)	22 (66.7)	NS

CLD, chronic lung disease; RDS, respiratory distress syndrome; NS, not significant.

Figure 1. AF concentration of matrix metalloproteinase-8 (MMP-8) and white blood cell (WBC) count according to the type of CLD. Mothers whose preterm babies had atypical CLD had a significantly higher median AF MMP-8 concentration and AF WBC count than those whose preterm babies had CLD with RDS (AF MMP-8: median 373.1, range <0.3 to 6142.6 ng/ml vs. median 8.6, range <0.3 to 4202.7 ng/ml; p = 0.003; AF WBC count: median 450.0, range 0 to >1000/mm³vs. median 5.5, range 0 to >1000/mm³; p = 0.009).

Table II.  Comparison of several inflammatory characteristics of the study population between cases with atypical CLD and those with CLD with RDS.

	Atypical CLD n = 39	CLD with RDS n = 33	p-value
Intra-amniotic infection [(+) AF culture] (%)*	11/38 (28.9)	7/32 (21.9)	NS
Intra-amniotic inflammation (AF MMP-8 > 23 ng/ml) (%)	29 (74.4)	15 (45.5)	0.012
Intra-amniotic infection and/or inflammation [(+) AF culture and/or AF MMP-8 > 23 ng/ml] (%)	31 (79.5)	15 (45.5)	0.003
Histological chorioamnionitis (%)**	19/31 (61.3)	15/29 (51.7)	NS
Funisitis (%)^†	9/31 (29.0)	6/30 (20.0)	NS

CLD, chronic lung disease; RDS, respiratory distress syndrome; NS, not significant; MMP-8, matrix metalloproteinase-8.

*Two cases were excluded from the analysis because of no results of the AF culture.

**Twelve cases that did not have histopathologic examination of the placenta were excluded from the analysis.

^†Eleven cases were excluded from the analysis due to unavailable placental histological results for funisitis.