Methods
For registrations to all pregnancy related events, we retrieved
information from Statistics Denmark. Statistics Denmark holds copies of
several national registries including the National Patient Registry,
which registers all in- and outpatient contacts in Denmark, including
procedural codes and dates of contact, using International
Classification of Diseases (ICD), 8th or
10th edition. Statistics Denmark utilized the civil
registration number and identified our Marfan syndrome women in the
registries and ensured identification of 100 age matched (year of birth)
female controls as well as accurate linkage of data. For two Marfan
syndrome women, no controls were given, thus, data were obtained for 195
Marfan syndrome women and their 19,500 controls, matched on age and
region.
Statistics Denmark holds no clinical data, for instance on aortic size
and blood pressure.