Objective: This study was to investigate the association of Bisphenol A and unexplained recurrent spontaneous abortion.
Methods: A hospital-based 1:1 matched case-control study was conducted. Sixty patients with unexplained recurrent abortion were included. Each case was matched with one normal control by age (± 2 years), living district and the same gestational age. The levels of Bisphenol A in urine for 60 cases and 60 controls were detected using high performance liquid chromatography after fluorescent derivatization. The levels of urinary Bisphenol A in case was compared with that in control in education levels, occupation, smoking history. Data was analyzed by means of Wilcoxon-test, Student-Newman-Keuls after rank transform, univariate and multivariate conditional Logistic regression analysis. The software used was SAS 9.1.3.
Results: The values of urinary Bisphenol A in cases and controls were (0.10 ± 0.21) µg/ml, (0.03 ± 0.08) µg/ml, respectively. The level of urinary Bisphenol A in cases was significantly higher than that in controls (Z = 3.988, P < 0.0001). The urinary Bisphenol A levels in cases were significant higher than those in controls from senior middle school (the levels were 0.10, 0.06 µg/ml respectively, Z = 1.996, P = 0.0459), college (the levels were 0.14, 0.03 µg/ml respectively, Z = 2.586, P = 0.0097), workers or farmers (the levels were 0.08, 0.03 µg/ml respectively, Z = 2.265, P = 0.0235), businessmen (the levels were 0.10, 0.03 µg/ml respectively, Z = 2.544, P = 0.0109), and no passive smokers (the levels were 0.09, 0.03 µg/ml respectively, Z = 3.767, P = 0.0002). After adjustment by age, body mass index, marital status during pregnancy and other factors, compared to Bisphenol A below 0.06 µg/ml, the adjusted OR was 4.03 (1.67 - 9.74) for Bisphenol A levels between 0.06 µg/ml and 0.20 µg/ml, and was 5.46 (1.95 - 15.27) for Bisphenol A over 0.20 µg/ml. The risk of unexplained recurrent spontaneous abortion increased progressively with the growth of urinary Bisphenol A levels (χ(2) = 13.042, trend test P = 0.0003). There were significant differences on Bisphenol A among controls, two abortions, and three or more abortions (the levels were 0.03 µg/ml, 0.09 µg/ml, 0.21 µg/ml respectively, F = 9.04, P = 0.0002).
Conclusion: Exposure to Bisphenol A may be associated with unexplained recurrent spontaneous abortion.