Predicting Complications in Women With Toxaemia

In North America, pre-eclampsia ('toxaemia of pregnancy') is the most common cause for women to die during or shortly after pregnancy. It is also the most common reason for babies who are otherwise doing well to be delivered prematurely; this is with the intent purpose of protecting maternal health and safety. In many ways it is similar to the systemic inflammatory response syndrome ('septicaemia').

This project is part of a three part strategy to better understand the mechanisms of disease in pre-eclampsia and to investigate a potential disease-modifying therapy, namely, recombinant human activated protein C. We have surveyed Canadian practice, and undertaken both feasibility and pilot studies for this project.

At present, the management of pre-eclampsia is guided by expert opinions that are not well-based on firm evidence. What is required is a clinical tool that can accurately determine a women's risk for adverse outcomes, and thereby reduce the risk for women while safely prolonging pregnancies remote from term (to improve fetal outcomes). This research project, 'a severity score for pre-eclampsia,' will develop such a clinical tool that is specific to the condition. To develop and validate the tool we will recruit 3000 women in Canada, the UK, and Australasia who are admitted to a hospital with either pre-eclampsia or one of its variants. At the same time, because the majority of deaths associated with pre-eclampsia occur in low and middle income countries, we will recruit 3000 women from Uganda, China, Fiji, South Africa and Pakistan with pre-eclampsia. We will use this cohort to test the model and ensure it accurately predicts risk in this new population.

This severity score will be used clinically (to guide management) and in research (in both clinical trials and basic science research), and will provide an evidence base on which to build future practice, improving outcomes for pregnant women and their babies.

Inclusion criteria

These criteria reflect the evidence that pre-eclampsia is more than hypertension and proteinuria, particularly at onset:

• Hypertension. sBP >140mmHg and/or dBP >90mmHg, twice, >4h apart after 20 weeks' gestation. sBP will be included to reflect international guidelines.
• Proteinuria. 24h urinary protein >0.3g/d3, or in the absence of a 24h urine collection: >2+ dipstick proteinuria after 20wk or a random protein:creatinine ratio >30mg protein/mmol creatinine106-108.
• HELLP syndrome that is non-hypertensive and non-proteinuric, using Sibai's criteria109,
• One eclamptic seizure without preceding hypertension or proteinuria ('BEST' definition of eclampsia38).
• Women admitted with suspected 'superimposed pre-eclampsia' will also be included (e.g., those with a history of pre-existing hypertension with new proteinuria (>2+) or accelerated hypertension3;23;24).

Exclusion criteria

• Occurrence of the maternal outcome (e.g., recurrent eclampsia) prior to collection of the predictors.
• Admission to hospital in spontaneous labour (as clinicians will not attempt to stop these labours).