Clinical features and outcomes of pregnancies complicated by pre-ecplampsia necessitating in-utero transfer
Introduction
Pre-eclampsia (PE), defined as hypertension with signs of end organ damage developing after 20 weeks’ gestation, is a leading cause of maternal and perinatal mortality and morbidity [1]. The World Health Organisation (WHO) estimates PE affects 10% of all pregnancies globally, and accounts for 14% of maternal mortality [2], [3]. In Australia, 6.3% of all maternal deaths between 2012 and 2014 were associated with PE [4]. End-organ complications of PE include proteinuria, acute renal failure, liver dysfunction and/or rupture, cerebrovascular stroke, pulmonary oedema, coagulation disorders and eclampsia [1]. Fetal consequences of severe PE include fetal growth restriction (FGR), placental abruption, stillbirth, preterm birth and neonatal death [5]. Pregnancies complicated by PE are considered high-risk given the associated risks of morbidity and mortality [6], [7].
All women with high-risk pregnancies should ideally be managed in a tertiary perinatal centre with access to maternal-fetal medicine specialists and neonatal intensive care facilities [7], [8], [9], [10]. This recommendation is based on data from local and international studies consistently demonstrating improved maternal [11] and fetal outcomes when high-risk pregnancies are managed in a tertiary perinatal centre [10], [12], [13], [14], [15].
In the State of Victoria, Australia, there are three tertiary level perinatal centres, available to receive referrals from 70 non-tertiary maternity services throughout the State. There are more than 80,000 births per annum in Victoria [16]. High-risk pregnancies requiring tertiary care can be transferred in-utero to one of these perinatal centres, which are all located in the Melbourne metropolitan area. A single centralised service, the Paediatric Infant Perinatal Emergency Retrieval (PIPER) coordinates in-utero transfers statewide.
Women transferred to a tertiary centre for specialist management of PE represent a unique population, as not all women who develop PE will require tertiary care. However, there are limited local contemporaneous data reporting characteristics and outcomes of this population. Most studies report outcomes of all in-utero transfers (with pre-eclampsia reported as a common indication for transfer) or report on transfers for threatened preterm labour only [17], [18], [19], [20].
Our aim was to report clinical features and outcomes of a population-based cohort of women referred to a statewide perinatal emergency service with a primary diagnosis of pre-eclampsia and subsequently transferred in-utero.
Section snippets
Methods
We conducted a retrospective population-based audit of consecutive pregnancies referred to PIPER in Victoria, Australia, over a two-year period from 1 January 2013 to 31 December 2014. Inclusion criteria were women referred to PIPER with a diagnosis of PE at or after 20 weeks’ gestation and subsequently transferred to a higher level of care for ongoing management. Levels of care were defined as primary maternity services (Level 1), secondary maternity services (Level 2) and tertiary maternity
Results
Over the two-year period, 2374 women were referred to the Perinatal Emergency Referral Service at PIPER during pregnancy. Of these, 244 (10%) were referred with a primary diagnosis of pre-eclampsia ≥20 weeks’ gestation (Fig. 1). Following consultation, 199/244 (82%) women were transferred in-utero.
Perinatal characteristics of the cohort are reported in Table 1. Mean gestational age at the time of in-utero transfer was 30.7 weeks’ gestation (SD 3.3 weeks). Overall, 64% (127/199) of women were
Discussion
This is the first study to report clinical features and outcomes of pregnancies referred to the statewide perinatal emergency service at PIPER in Victoria with a primary diagnosis of pre-eclampsia at or after 20 weeks’ gestation, and subsequently transferred in-utero.
We found women referred to PIPER predominantly had severe pre-eclampsia. Proteinuria was reported in 72% of cases and a wide range of other signs and symptoms, including raised uric acid, neurological symptoms, altered hepatic and
Limitations
As this was a retrospective study, clinical features at the time of referral to PIPER were limited to data recorded in the PIPER perinatal consultation records. Outcome data were only collected until 7 days post transfer and were limited to birth details (gestational age, birth weight, sex, mode of delivery) and major maternal morbidity. Long-term maternal and neonatal morbidity could not be identified. Moreover, the population presented in this audit is a subset of patients, and therefore
Strengths
We have reported outcomes from a statewide dataset of all perinatal referrals to PIPER over a continuous two-year time-period. We reported outcomes on every woman referred to PIPER with PE and transferred in-utero. This enabled identification of the complexity of clinical presentations, acute management and outcomes of these pregnancies.
Conclusion
Management of women who develop pre-eclampsia necessitating in-utero transfer to a higher level of care requires an individualised approach. Consultation and collaboration with the referring and receiving hospital clinician, the Ambulance Service, and tertiary obstetric and neonatal staff is essential to ensure safe and timely in-utero transfer. Data from studies such as ours demonstrate the critical role of a regionalised perinatal emergency referral service in providing equitable and timely
Acknowledgements
The authors wish to thank Christine Fry and Frank Millen for their assistance with case identification and selection, and the staff of PIPER for their assistance with data queries during data extraction.
Contributors
SR and RAB designed the study, wrote the ethics and analysed the data. SR wrote the draft manuscript. RAB, SB, JS and MS supervised and contributed to the study design, and edited the manuscript. Each author has reviewed the manuscript and approved submission of this version. The authors take full responsibility for the manuscript. At the time of the study’s design and data collection, SR was a final year medical student at the University of Melbourne.
Declarations of interest
None.
Funding
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
RAB currently holds a Postdoctoral Research Fellowship funded by the Murdoch Children’s Research Institute, Melbourne.
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