Mercury-induced Oxidative Stress May Adversely Affect Pregnancy Outcome among Dental Staff: A Cohort Study

BACKGROUND: Dental staff may be at increased risk of adverse pregnancy outcome secondary to their chronic exposure to mercury. OBJECTIVE: To investigate obstetric outcome among dental staff and explore the oxidative stress induced by mercury exposure. METHODS: A cohort of 64 pregnant dental staff (exposed group) and 60 pregnant employees (non-exposed group) were studied. Urinary mercury level and blood antioxidant activity were measured. Participants were followed to assess their obstetric outcome. RESULTS: The exposed group had a higher mean urinary mercury level and a lower blood antioxidant activity during the three trimesters compared to non-exposed group (p<0.001). Women in the exposed group were experienced more frequently spontaneous abortion and pre-eclampsia (p<0.05). Babies born to the women in the exposed group tended to be smaller for gestational age compared to those of non-exposed group (p<0.001). CONCLUSION: Pregnant dental staff suffered higher odds of developing spontaneous abortion and pre-eclampsia and giving birth to babies smaller for gestational age. This may be linked to oxidative stress induced by exposure to mercury.