It may be difficult to interpret and compare much of literature due to varying definitions and diagnostic criteria for pregnancy-induced hypertension and preeclampsia.
The treatment thresholds and goals for blood pressure during pregnancy also vary greatly.
Many of the trials are observational studies or retrospective chart reviews; thus, it is hard to determine if other factors obscure the results.
Smaller study populations in some clinical trials may make it more difficult to apply results to a larger population.