Main findings
For the first time, in an unbiased population of women with Marfan syndrome, including both pre-pregnancy undiagnosed and diagnosed cases, we show that pregnancy is relatively safe in diagnosed women with Marfan syndrome. However, undiagnosed Marfan syndrome is associated with birth-related aortic disease.
We also identified a significantly decreased number of registrations related to maternal health, indicative of fewer pregnancies, relative to the background population among diagnosed females with Marfan syndrome, while women not yet diagnosed with Marfan syndrome had just as many pregnancies as in the background population. Thus, knowledge of the diagnosis seems to impact both women with Marfan syndromes decisiveness and how the health care system advices on pregnancy.