Comparison of possible risk factors for developing severe maternal morbidity and mortality caused by cardiovascular disease between cases and the general pregnant population.

n/a = data not available. RR = relative risk (95% confidence interval) significant.*includes hypertension, diabetes, cardiac disease and coagulation disorders. National reference values from.**[11] Statistics Netherlands (exact study period) and.***[12] The Netherlands Perinatal Registry (LVR-2, 2005).