Table 4.

Differences in birthweight between neonates born to women with and without Chlamydia trachomatis infection

	Number (%)	Mean birth weight SDS	Difference in birthweight SDS*
			Unadjusted	Adjusted#
Gestational age
< 32 weeks (n = 22)
C. trachomatis −	18 (82)	0.83
C. trachomatis +	4 (18)	−0.72	−1.54 (−3.6–0.5)	−1.43 (−4.6–1.7)
< 35 weeks (n = 64)
C. trachomatis −	57 (89)	0.13
C. trachomatis +	7 (11)	−0.87	−0.99 (−2.2–0.2)	−0.79 (−2.2–0.7)
< 37 weeks (n = 190)
C. trachomatis −	180 (95)	−0.26
C. trachomatis +	10 (5)	−0.85	−0.59 (−1.4–0.2)	−0.38 (−1.2–0.4)
≥ 37 weeks (n = 3,723)
C. trachomatis −	3,583 (96)	−0.08
C. trachomatis +	140 (4)	−0.19	−0.10 (−0.3–0.1)	−0.12 (−0.1–0.3)

SDS standard deviation score

^#Adjusted for maternal age, ethnicity, education, gravidity and smoking

Difference and 95% confidence interval calculated with linear regression analysis