Particulate Air Pollution, Blood Mitochondrial DNA Copy Number, and Telomere Length in Mothers in the First Trimester of Pregnancy: Effects on Fetal Growth

Table 1

Description of study population.

	Mean ± SD or range and number
Mother ()
Age (years)	33.0 (3.9)
Gestational age at examination (weeks)	11.9 (0.5)
Prepregnancy BMI (kg/m^2)	22.5 (4.0)
BMI, categorical
BMI < 25 kg/m^2	155 (77.9)
BMI ≥ 25 kg/m^2	44 (22.1)
Self-reported smoking status
Never smoker	151 (75.9)
Past smoker	30 (15.1)
Current smoker	18 (9.1)
Parity
0	121 (60.8)
1	67 (33.7)
2	10 (5.0)
3	1 (0.5)
Season of enrolment
Autumn	63 (31.7)
Winter	41 (20.6)
Spring	41 (20.6)
Summer	54 (27.1)
Newborn ()
Sex
Male	108 (56.8)
Female	82 (43.2)
Gestational age at delivery (weeks)	38.8 (1.4)
Birth weight (g)	3272.9 (477.9)
Birth length (cm)	49.9 (2.0)
Birth head circumference (cm)	34.2 (1.5)
Crown-rump length (CRL) (mm)	62.2 (6.9)
Nuchal translucency (NT) (cm)	1.9 (0.4)
Fetal heart rate (FHR) (bpm)	160.4 (6.1)

7 miscarriages and two mothers lost to follow-up.