Table 2

Risk of PROM and preterm PROM associated with the levels of Pb in maternal urine

Pb (μg/g creatinine)CaseOR* (95% CI)OR (95% CI)
PROM
 Tertile 1 (<2.65)2411.001.00
 Tertile 2 (2.65–4.70)2911.24 (1.03 to 1.48)1.23 (1.02 to 1.47)
 Tertile 3 (≥4.70)3491.52 (1.27 to 1.81)1.51 (1.27 to 1.80)
 P for trend<0.01<0.01
Preterm PROM
 Tertile 1 (<2.65)371.001.00
 Tertile 2 (2.65–4.70)461.25 (0.81 to 1.93)1.24 (0.80 to 1.92)
 Tertile 3 (≥4.70)641.74 (1.16 to 2.62)1.73 (1.15 to 2.60)
 P for trend<0.01<0.01
  • *Unadjusted OR.

  • †Adjusted for maternal age, family income, pre-BMI, parity, passive smoking and pregnancy-induced hypertension.

  • Pb, lead; PROM, premature rupture of membranes.