Interpretation of findings
We hypothesised that the four subgroups of women with CH represent different stages of the disease. Studies in non-pregnant individuals have demonstrated that in the progression from normal blood pressure to mild and then severe hypertension there is increasing endothelial dysfunction. Groups 1 and 2 are likely to represent the early phase of CH with mild endothelial dysfunction but sufficient ability to achieve physiological adaptation to pregnancy with normalisation of BP in the latter group. Groups 3 and 4 may represent moderate to severe endothelial dysfunction with less capacity to achieve early vasodilation and normalisation in BP without antihypertensive medications. We further postulated that the severity of underlying endothelial disease, as represented by the four groups, might be reflected in the first trimester angiogenic and inflammatory profiles.