This unprecedented about-turn marked the sudden end of a lawsuit that had been mounted by advocacy groups, such as Moms Against Mercury, who are seeking to ban the use of mercury in amalgam fillings and children's vaccinations.
In an official statement, which has been posted on the FDA website, the regulator admitted that mercury-containing dental fillings "may have neuro-toxic effects on the nervous systems of developing children and fetuses."
The statement puts the US in line with a handful of other countries that already ban the use of mercury fillings in pregnant women. The FDA is calling for further research, and may announce a complete ban on amalgam fillings next year.
As we exclusively reported in an earlier E-news bulletin, Denmark imposed a complete ban on amalgam fillings this year.
In the meantime, pregnant women, and people with "a health condition that makes them more sensitive to mercury exposure", or with high levels of mercury already, should talk to their dentists about safer alternatives, the FDA has announced.
Mercury has also been traditionally used as a preservative in children's vaccinations, although the process of removing it began in 2000, and current stocks contain no mercury-based thimerosal.
(Source: FDA website).