Association between light rare earth elements in maternal plasma and the risk of spontaneous preterm birth: a nested case-control study from the Beijing birth cohort study

Table 3 Association between rare earth elements and SPB in the third trimester

Elements	Case	Control	OR	AOR
La
low	74 (30.3)	89 (36.6)	1.00	1.00
intermediate	90 (36.9)	72 (29.6)	1.50 (0.97–2.33)	1.70 (1.07–2.68) *
high	80 (32.8)	82 (33.7)	1.17 (0.76–1.81)	1.28 (0.81–2.02)
P_trend			0.471	0.289
Ce
low	79 (32.4)	84 (34.6)	1.00	1.00
intermediate	79 (32.4)	83 (34.2)	1.01 (0.66–1.56)	1.05 (0.67–1.64)
high	86 (35.2)	76 (31.3)	1.20 (0.78–1.86)	1.25 (0.80–1.96)
P_trend			0.405	0.327
Pr
low	77 (31.6)	86 (35.4)	1.00	1.00
intermediate	70 (28.7)	92 (37.9)	0.85 (0.55–1.32)	0.88 (0.56–1.37)
high	97 (39.8)	65 (26.7)	1.67 (1.07–2.59) *	1.65 (1.05–2.59) *
P_trend			0.023*	0.033*
Nd
low	81 (33.2)	82 (33.7)	1.00	1.00
intermediate	79 (32.4)	83 (34.2)	0.96 (0.62–1.49)	1.04 (0.66–1.62)
high	84 (34.4)	78 (32.1)	1.09 (0.71–1.68)	1.12 (0.71–1.75)
P_trend			0.698	0.626
Sm
low	74 (30.3)	89 (36.6)	1.00	1.00
intermediate	89 (36.5)	73 (30.0)	1.47 (0.95–2.27)	1.43 (0.91–2.24)
high	81 (33.2)	81 (33.3)	1.20 (0.78–1.86)	1.23 (0.78–1.92)
P_trend			0.405	0.365
Eu
low	147 (60.2)	151 (62.1)	1.00	1.00
high	97 (39.8)	92 (37.9)	1.08 (0.75–1.56)	1.11 (0.76–1.62)

^a: Adjusted for ethnicity (Han & others), education level (Junior college and below, Undergraduate & Postgraduate and above), age (20–29, 30–34 & ≥35), BMI (slim, normal & overweight), parity (Primiparous & Multiparous), and family income (< 10,000, 10,000–19,999 & ≥20,000)
*: P < 0.05

ISSN: 1476-069X