Table 6.

Geometric Mean Levels of Proinflammatory Cytokines in Small- and Appropriate-for-Gestational-Age Preterm Births (n = 62)^a, by Reason for Preterm Delivery, Infant Growth Project, Jefferson County, Alabama, 1985–1988

	Small-For-Gestational-Age Birth			Appropriate-For-Gestational-Age Birth			P Valueb
	No.	GM, pg/mL	95% CI	No.	GM, pg/mL	95% CI
Interleukin-12
Spontaneous/PROM preterm birth	8	3.3	2.4, 4.8	49	4.5	3.9, 5.3	0.06
Indicated preterm birth	2	3.7	1.2, 11.6	3	5.9	2.2, 11.1	0.34
Interferon γ
Spontaneous/PROM preterm birth	8	3.3	2.1, 5.2	49	8.4	6.4, 11.0	<0.01
Indicated preterm birth	2	6.2	0.6, 60.3	3	9.9	2.2, 44.3	0.36
Tumor necrosis factor α
Spontaneous/PROM preterm birth	8	7.9	6.9, 9.2	49	10.9	9.7, 12.3	0.02
Indicated preterm birth	2	12.6	11.4, 13.9	3	12.3	11.2, 13.4	0.64

Abbreviations: CI, confidence interval; GM, geometric mean; PROM, premature rupture of the membranes.

^aThere were 72 preterm births in the study population. However, for 10 of these births, information on the type of preterm delivery was missing. There was 1 large-for-gestational-age preterm baby, who was grouped with appropriate-for-gestational-age births.

^bP value was calculated using Fisher's exact test.