Therapeutic anticoagulation may be required during pregnancy to treat venous thromboembolism (VTE), for patients considered to be at high risk of thrombosis and for the management of mechanical heart valves (MHVs). Expert opinion varies on the use of therapeutic anticoagulation during the peripartum period. To date no randomised control trials have been undertaken to evaluate best practice. This is a highly specialised area of Obstetric Medicine with patients often managed in the tertiary hospital setting. This Master of Philosophy thesis aimed to investigate the current practices regarding therapeutic anticoagulation during the peripartum period to add to the body of knowledge surrounding this specialised area of Obstetric Medicine and ultimately lead to improved patient care. In this study, the peripartum period was defined as 28 days prior to and post delivery.With few evidence based recommendations available, Phase 1 of this research assessed current clinical practice by conducting a 2 year retrospective study investigating women who received therapeutic unfractionated heparin (UFH) during the peripartum period. Prescribing and administration information was obtained from the Queensland Health heparin infusion order form and medical notes were studied to document the approaches utilised when prescribing therapeutic heparin. The results of this study suggested that variance from the Queensland Health heparin infusion protocol or specific specialist instructions occur in a number of key areas. Lack of familiarity with the Queensland Health heparin infusion protocol may be a significant factor, as well as a lack of underlying knowledge about prescribing heparin in the peripartum period. Often specific instructions are outlined by the treating consultant when prescribing therapeutic UFH to mitigate the risk associated with post-partum haemorrhage. The desire by clinicians to target a lower activated partial thromboplastin time (APTT) range during the postnatal peripartum period to balance bleeding risk was highlighted by this study however, currently there is no evidence that this is best clinical practice with further research required to address this gap. To further ascertain the variations in clinical practice profiles at a national level, Phase 2 surveyed the management of therapeutic anticoagulation during the postnatal peripartum period around Australia and New Zealand. The survey results indicated that the respondent’s anticoagulant of choice in this setting is LMWH for both women considered at low and high risk of rethrombosis. Most clinicians would recommence LMWH subtherapeutically 6 hours post delivery and then increase to therapeutic at 12-24 hours. In women with MHVs a majority of respondents would utilise UFH with a trend to earlier recommencement of therapeutic anticoagulation in this high risk group. This may reflect the desire for more aggressive anticoagulation in these high risk patients with UFH providing the reassurance of reversibility should bleeding occur. Results from the study indicated that practice regarding the utilisation of bolus dosing is varied. Whilst a majority of respondents indicated it was usual to omit bolus dosing when using therapeutic UFH in the postnatal peripartum period, in patients considered being at high risk of thrombosis, some clinicians may elect to optimise UFH therapy by use of bolus dosing. Whilst the survey included a relatively small cohort of respondents, the results do indicate certain trends that exist amongst therapeutic anticoagulation in the postnatal peripartum period. However, it is evident that practice is varied around Australia and New Zealand and highlights the challenges facing clinicians and the need for further research. Further research into the most efficacious management options would assist clinicians in the development of evidence based guidelines protocols and policy.Phase 3 of the research consisted of a case series of patients prescribed therapeutic UFH in accordance with a low target APTT range nomogram. Whilst the small patient numbers in this study precludes meaningful statistical analysis, it is evident that the provision of a low target APTT range guideline provides a platform to which clinicians can refer and individualise patient treatment.The use of therapeutic UFH during the peripartum period is a specialist area which is reflected by the small patient numbers. This should however not diminish the overall importance of the research as the complex nature of these cases warrants investigation to optimise and improve management. This study has identified a number of key findings. Firstly, in order to optimise the management of UFH infusions, further education and competency training of medical and nursing staff caring for women requiring therapeutic anticoagulation during the peripartum partum period is required. Secondly, revisiting the development and implementation of state-wide healthcare guidelines would likely aid clinicians by providing a resource to which to refer to assist in the management of these complex patients. Thirdly, further research is required to validate the use of a low target APTT range nomogram for use during the peripartum period.
