Table 3.

Associations between PFASs (ng/mL) and irregular and long cycles in preconception women in Shanghai, China, 2013–2015.

PFASs	Irregular cycle			Long cycle
	$n$	Crude OR (95%CI)	Adjusteda OR (95%CI)	$n$	Crude OR (95%CI)	Adjusteda OR (95%CI)
PFOA
Continuousb	947	1.34 (0.97, 1.85)	1.52 (1.08, 2.15)	924	1.38 (1.00, 1.92)	1.50 (1.06, 2.10)
Q1 ($\le 10.08$)	238	ref	ref	231	ref	ref
Q2 (10.08–13.84)	236	1.67 (1.04, 2.66)	1.71 (1.05, 2.78)	231	1.49 (0.93, 2.38)	1.50 (0.92, 2.42)
Q3 (13.84–18.83)	236	1.32 (0.82, 2.14)	1.34 (0.81, 2.22)	231	1.20 (0.74, 1.94)	1.21 (0.73, 1.99)
Q4 ($>18.83$)	237	1.70 (1.07, 2.70)	1.99 (1.22, 3.24)	231	1.76 (1.11, 2.79)	1.95 (1.21, 3.14)
PFOS
Continuousb	947	1.26 (0.97, 1.63)	1.29 (0.98, 1.70)	924	1.32 (1.01, 1.71)	1.34 (1.02, 1.75)
Q1 ($\le 7.55$)	238	ref	ref	230	ref	ref
Q2 (7.55–10.49)	237	0.85 (0.53, 1.36)	0.93 (0.57, 1.51)	235	1.03 (0.65, 1.65)	1.11 (0.69, 1.80)
Q3 (10.49–15.37)	236	1.24 (0.80, 1.94)	1.27 (0.80, 2.03)	230	1.21 (0.77, 1.92)	1.30 (0.81, 2.08)
Q4 ($>15.37$)	236	1.24 (0.80, 1.94)	1.32 (0.83, 2.09)	229	1.38 (0.88, 2.17)	1.44 (0.90, 2.30)
PFNA
Continuousb	947	1.37 (0.98, 1.91)	1.50 (1.03, 2.07)	924	1.42 (1.01, 1.99)	1.49 (1.05, 2.11)
Q1 ($\le 1.04$)	234	ref	ref	232	ref	ref
Q2 (1.04–1.36)	242	1.27 (0.79, 2.03)	1.24 (0.76, 2.02)	230	1.31 (0.82, 2.10)	1.36 (0.84, 2.22)
Q3 (1.36–1.85)	233	1.34 (0.84, 2.12)	1.38 (0.85, 2.23)	235	1.38 (0.86, 2.20)	1.48 (0.92, 2.40)
Q4 ($>1.85$)	238	1.52 (0.96, 2.40)	1.60 (0.99, 2.58)	227	1.59 (1.00, 2.53)	1.67 (1.03, 2.70)
PFHxS
Continuousb	947	1.66 (1.10, 2.51)	1.80 (1.17, 2.77)	924	1.65 (1.08, 2.50)	1.73 (1.13, 2.65)
Q1 ($\le 0.56$)	235	ref	ref	230	ref	ref
Q2 (0.56–0.69)	240	1.50 (0.91, 2.46)	1.41 (0.84, 2.35)	235	1.44 (0.87, 2.38)	1.35 (0.81, 2.25)
Q3 (0.69–0.88)	232	2.12 (1.31, 3.43)	2.16 (1.31, 3.57)	228	2.24 (1.39, 3.62)	2.24 (1.37, 3.66)
Q4 ($>0.88$)	240	2.06 (1.28, 3.34)	2.14 (1.30, 3.51)	231	2.05 (1.27, 3.33)	2.08 (1.27, 3.40)

Note: Irregular cycle is defined as $\ge 7\text{d}$ of variation. Long cycle is defined as $>35\text{d}$ and is compared with a normal cycle (21–35 d) as reference (ref).

^aAdjusted for age (continuous), BMI (continuous), income (categorical), age at menarche (continuous) and parity (categorical).

^bLog-transformed PFASs as continuous variables.