Background: This article is a critical appraisal of a study done in 2016 that examined whether exposure to dental amalgam during pregnancy affected birth outcomes.
Clinical question: Does exposure to amalgam restorations during pregnancy affect birth outcomes?
Methods and results: This study is a prospective cohort study of 69,474 pregnancies and subsequent birth outcomes. Two questionnaires were sent out to pregnant Norwegian women at 17 and 30 weeks of pregnancy in order to determine exposure to dental amalgam. The data was then linked to the Medical Birth Registry of Norway, which records all pregnancy outcomes in the country. Logistic regression was performed to determine whether a mother's exposure to amalgam during pregnancy affected birth outcomes. The logistic regression revealed that the pregnancy outcomes early preterm delivery, late preterm delivery, low birth weight, malformation, and stillbirth were unrelated to the number of teeth with amalgam restorations during pregnancy. The authors found no evidence that exposure to dental amalgam during pregnancy is associated with serious perinatal outcomes after adjusting for confounding variables. This study was well planned and well implemented, and the findings are consistent with the findings of other large-scale studies done by independent groups.
Clinical implications: There is no evidence to suggest that the presence or placement of dental amalgam restorations during pregnancy will adversely affect birth outcomes. Practitioners should present this evidence to those patients who are thinking of delaying dental treatment until after pregnancy out of concerns regarding prenatal effects of amalgam.