Nature Reviews Rheumatology 16, 113–122 (2020) https://doi.org/10.1038/s41584-019-0351-2 Published online 13 January 2020

In the originally published version of this article there was an error in the text. The line beginning “However, the developing fetus is not recognized by the maternal immune system […]” has been corrected to “However, the developing fetus is recognized by the maternal immune system […]”. This error has now been corrected in the HTML and PDF versions of the manuscript.