Table 2.

Baseline characteristics of the 864 sons, enrolled in the FEPOS cohort between 2017 and 2019 and their mothers, according to tertiles of maternal plasma PFOS concentrations.

Characteristics	All	Maternal PFOS level in tertiles
		Low	Medium	High
	$n=864$	$n=288$	$n=288$	$n=288$
Mother
Age at birth (y) ($\text{mean}\pm \text{SD}$)	$31\pm 4$	$31\pm 4$	$30\pm 4$	$30\pm 4$
Prepregnancy BMI (${\mathrm{kg}/\mathrm{m}}^2$) [median (5th–95th P)a	22 (18–30)	22 (18–28)	22 (19–30)	23 (18–31)
Smoking in first trimester [$n$ (%)]
Nonsmoker	668 (77)	217 (76)	222 (77)	229 (80)
Light smoker	168 (19)	64 (22)	56 (19)	48 (17)
Heavy smoker	28 (3)	7 (2)	10 (3)	11 (4)
Household occupational status [$n$ (%)]
High-grade profession	290 (34)	102 (35)	98 (34)	90 (31)
Low-grade profession	288 (33)	99 (34)	92 (32)	97 (34)
Skilled or unskilled worker	247 (29)	77 (27)	79 (27)	91 (32)
Student or economically inactive	39 (5)	10 (3)	19 (7)	10 (3)
Parity [$n$ (%)]
Primipara	374 (44)	94 (33)	127 (45)	153 (55)
Multipara	473 (56)	187 (67)	159 (55)	127 (45)
Son
Age at clinical visit (y) ($\text{mean}\pm \text{SD}$)	$19\pm 0$	$19\pm 0$	$19\pm 0$	$19\pm 0$
BMI (${\mathrm{kg}/\mathrm{m}}^2$) [median (5th–95th P)]a	22 (18–28)	22 (18–28)	22 (18–27)	22 (18–29)
Smoking habits [$n$ (%)]
Never	405 (47)	123 (43)	132 (46)	150 (52)
Occasional or former smoker	245 (28)	75 (26)	79 (28)	91 (32)
Current smoker	211 (25)	89 (31)	76 (26)	46 (16)
Time of day for blood sampling [$n$ (%)]
Morning	310 (36)	100 (35)	100 (35)	110 (39)
Midday	454 (53)	156 (55)	152 (54)	146 (51)
Evening	91 (11)	30 (10)	32 (11)	29 (10)
Minutes from semen collection to analysis ($\text{mean}\pm \text{SD}$)	$50\pm 20$	$50\pm 19$	$52\pm 22$	$49\pm 19$
Period of abstinence (d) [$n$ (%)]
$<2$	296 (35)	110 (39)	93 (32)	93 (33)
2–4	508 (60)	149 (53)	184 (64)	175 (62)
$\ge \mathrm{5}$	47 (6)	21 (8)	10 (3)	16 (6)
Spillage of semen sample [$n$ (%)]
Spillage	149 (17)	57 (20)	41 (14)	51 (18)
No spillage	707 (83)	227 (80)	246 (86)	234 (82)

Note: Tertiles are as follows: low ($\mathrm{6}.\mathrm{28}–\mathrm{23}.\mathrm{38}\mathrm{ng}/\mathrm{mL}$), medium ($\mathrm{23}.\mathrm{51}–\mathrm{31}.\mathrm{49}\mathrm{ng}/\mathrm{mL}$), high ($\mathrm{31}.\mathrm{66}–\mathrm{92}.\mathrm{59}\mathrm{ng}/\mathrm{mL}$). Missing: Maternal age ($n\le \mathrm{5}$), prepregnancy BMI ($n=22$), maternal smoking ($n=0$), household occupational status ($n=0$), parity ($n=\mathrm{17}$), age at clinical visit ($n=0$), BMI ($n\le \mathrm{5}$), smoking habits ($n\le \mathrm{5}$), time of day for blood sampling ($n=\mathrm{9}$), minutes from semen collection to analysis ($n=\mathrm{11}$), days of abstinence ($n\le \mathrm{5}$, spillage ($n=8$). BMI, body mass index; FEPOS, Fetal Programming of Semen Quality; P, percentile; PFOS, perfluorooctane sulfonic acid; SD, standard deviation.

^a Pseudo median and percentiles were based on information from at least five individuals with values closest to the actual median/percentile.