Table 1.

Characteristics of the included ($n=356$) and excluded ($n=128$) population from the cohort SEPAGES in this study. Included population corresponds to children who had at least both one prenatal oxidative potential assessment and one test of lung function.

Characteristics	Included populationa ($n=356$)	Excluded populationa ($n=128$)	$p$-Valueb
Sex of child	—	—	0.2
Male	185 (52%)	73 (59%)	—
Female	171 (48%)	51 (41 %)	—
Missing	0	4	—
Birth weight (g)	—	—	0.13
Median (IQR)	3,295 (3,048, 3,580)	3,220 (2,995, 3,507)	—
Missing	0	5	—
Preterm birth ($<37$ wk)	—	—	0.2
0 (No)	341 (96%)	115 (93%)	—
1 (Yes)	15 (4%)	9 (7%)	—
Missing	0	4	—
Parental educational level $>5$ y	—	—	0.048
0 (No)	100 (28%)	48 (38%)	—
1 (Yes)	256 (72%)	80 (62%)	—
Delivery mode	—	—	0.084
Vaginal	302 (85%)	96 (78%)	—
C-section	54 (15%)	27 (22%)	—
Missing	0	5	—
Still breastfed at 6 wk	—	—	0.11
0 (No)	49 (14%)	20 (20%)	—
1 (Yes)	306 (86%)	78 (80%)	—
Missing	1	30	—
Parental history of rhinitis	—	—	0.003
0 (No)	132 (40%)	26 (24%)	—
1 (Yes)	202 (60%)	83 (76%)	—
Missing	22	19	—
Parity	—	—	0.6
0 (nulliparous)	160 (45%)	62 (48%)
1 (primiparous)	162 (46%)	52 (41%)
2 or more (multiparous)	34 (9.6%)	14 (11%)
ETS in utero and $<6$ wk	—	—	0.7
0 (No)	259 (73%)	84 (75%)	—
1 (Yes)	95 (27%)	28 (25%)	—
Missing	2	16	—
ETS $<3$ y	—	—	0.7
0 (No)	270 (79%)	70 (77%)	—
1 (Yes)	73 (21%)	21 (23%)	—
Missing	13	37	—
Exposure to particulate air pollutionc
${\mathrm{PM}}_{2.5}$ (${\mathrm{\mu }\mathrm{g}/\mathrm{m}}^3$)	13.3 (10.6, 17.5)	12.2 (8.2, 16.6)	0.033
Missing	0	79	—
${\text{OP}}_{\mathrm{v}}^{\mathrm{DTT}}$ (${\text{nmol}/\text{min}/\mathrm{m}}^3$)	1.49 (1.11, 2.00)	1.53 (1.05, 1.91)	0.8
Missing	0	97	—
${\text{OP}}_{\mathrm{v}}^{\mathrm{AA}}$ (${\text{nmol}/\text{min}/\mathrm{m}}^3$)	1.56 (1.07, 2.21)	1.66 (0.93, 2.30)	$>0.9$
Missing	0	97
Mean temperature during pregnancy (°C)
Median (IQR)	13.0 (10.6, 14.6)	11.6 (10.1, 13.6)	0.001
Missing	0	4
${\mathrm{N}}_2\mathrm{M}\mathrm{B}\mathrm{W}$ parametersc (6 wk)
FRC (mL)	105 (95, 115)	108 (95, 115)	0.6
Missing	72	62	—
LCI	7.58 (6.75, 8.47)	7.49 (6.99, 8.12)	0.9
Missing	72	62	—
TBFVL parametersc (6 wk)
${\mathrm{V}}_{\mathrm{T}}$ (mL)	34 (29, 39)	33 (29, 36)	0.4
Missing	47	112	—
${\mathrm{t}}_{\text{PTEF}}{/\mathrm{t}}_{\mathrm{E}}$ (%)	35 (29, 42)	36 (26, 45)	0.8
Missing	47	112	—
AOS parametersc (3 y)
${\text{Rrs}}_7$ ($\text{hPa}\times \mathrm{s}/\mathrm{L}$)	11.53 (10.05, 13.04)	12.67 (10.87, 14.17)	0.021
Missing	108	70	—
${\text{Rrs}}_{7–19}$ ($\text{hPa}\times \mathrm{s}/\mathrm{L}$)	1.02 (0.56, 1.61)	1.18 (0.63, 1.98)	0.2
Missing	108	70	—
${\text{Xrs}}_7$ ($\text{hPa}\times \mathrm{s}/\mathrm{L}$)	$-3.88$ ($-4.56$, $-3.28$)	$-4.25$ ($-5.59$, $-3.51$)	0.037
Missing	108	70	—
AX ($\text{hPa}/\mathrm{L}$)	68 (45, 92)	70 (53, 105)	0.3
Missing	108	70	—

Note: —, no data; AA, ascorbic acid; AOS, airwave oscillometry; DTT, dithiothreitol; AX, area under the reactance curve; ETS, environmental tobacco smoke; FRC, functional residual capacity; LCI, lung clearance index; ${\mathrm{N}}_2\text{MBW}$, nitrogen multiple-breath washout; OP, oxidative potential; ${\text{OP}}_{\mathrm{v}}^{\mathrm{AA}}$, volume-normalized oxidative potential measured by the AA assay; ${\text{OP}}_{\mathrm{v}}^{\mathrm{DTT}}$, volume-normalized oxidative potential measured by the DTT assay; PM, particulate matter; ${\mathrm{PM}}_{2.5}$, PM with an aerodynamic diameter $<2.5\mathrm{\mu }\mathrm{m}$; ${\text{Rrs}}_7$, resistance at a frequency of 7 Hz; ${\text{Rrs}}_{7–19}$, difference between the resistance at 7 Hz and at 19 Hz; TBFVL, tidal breathing flow-volume loops; ${\mathrm{t}}_{\text{PTEF}}{/\mathrm{t}}_{\mathrm{E}}$ ratio of time to peak tidal expiratory flow to expiratory time; ${\mathrm{V}}_{\mathrm{T}}$, tidal volume, ${\text{Xrs}}_7$, reactance at a frequency of 7 Hz.

^a Expressed in $n$ (%) or Median (IQR).

^b $p$-Value from Wilcoxon rank sum test and Pearson’s chi-squared test comparing included and excluded population.

^c Variables used for population selection (selected children had prenatal exposure to PM and OP and either ${\mathrm{N}}_2\text{MBW}$ or TBFVL or AOS measures).