Main findings
We have shown that a CPM based on pre-pregnancy and early pregnancy variables can moderately discriminate women destined for a severely morbid event or death from those likely to have uncomplicated pregnancies. The inclusion of prior pregnancy factors slightly enhanced these metrics. Our CPM displayed good calibration, indicating that a combination of routinely measured pre-pregnancy and early pregnancy factors can estimate the absolute risk of acute end-organ injury or death with reasonable accuracy. Using this CPM effectively increased the probability of identifying a very high-risk woman with this outcome by 40%, and reduced the probability in someone considered very low-risk by 20%31, but was less useful in classifying women in intermediate risk categories. This suggests that additional clinical, laboratory, or paraclinical factors are needed to accurately predict morbidity in all women, and further, that a certain proportion of these events are truly sudden and unpredictable.