Associations of maternal exposure to fine particulate matter with preterm and early-term birth in high-risk pregnant women

Table 2 Crude and adjusted odds ratios and their 95% CI for high-level PM_2.5 of preterm birth and early term birth

Outcomes	Trimester 1		Trimester 2		Trimester 3		Entire pregnancy
Outcomes	OR (95% CI)	P	OR (95% CI)	P	OR (95% CI)	P	OR (95% CI)	P
Crude model¹
Full-term birth	1.00		1.00		1.00		1.00
Preterm birth	0.96(0.79,1.15)	0.654	0.90(0.74,1.10)	0.324	1.29(1.04,1.59)	0.021	0.84(0.71,1.00)	0.054
Early term birth	0.83(0.75,0.93)	0.002	1.06(0.94,1.18)	0.331	1.39(1.23,1.58)	< 0.001	1.03(0.93,1.13)	0.611
Adjusted model²
Full-term birth	1.00		1.00		1.00		1.00
Preterm birth	1.12(0.86,1.47)	0.396	1.00(0.76,1.32)	0.984	1.43(1.05,1.93)	0.021	0.68(0.50,0.94)	0.019
Early term birth	0.90(0.77,1.06)	0.204	0.99(0.84,1.17)	0.923	1.29(1.09,1.54)	0.004	0.87(0.72,1.05)	0.156

High-level PM_2.5: average concentration over the specified time period ≥ 75 µg/m³
1: Logistic regression model, adjusted for maternal age and BMI
2: Logistic regression model, adjusted for maternal age, BMI, exposure to hazardous poison, number of previous deliveries, the season of conception, the year of conception, sex of the baby, mode of delivery, hyperglycemia, hypertension, scarred uterus, uterine fibroids, ovarian cyst, in vitro fertilization and the PM_2.5 exposure level during earlier stages of pregnancy

ISSN: 1880-7062