Peter Muller

Guidelines for the management of hypertensive disorders of pregnancy 2008

This is the Executive Summary of updated guidelines developed by the Society of Obstetric Medicine of Australia and New Zealand for the management of hypertensive diseases of pregnancy. They address a number of challenging areas including the definition of severe hypertension, the use of automated blood pressure monitors, the definition of non‐proteinuric pre‐eclampsia and measuring proteinuria. Controversial management issues are addressed such as the treatment of severe hypertension and other significant manifestations of pre‐eclampsia, the role of expectant management in pre‐eclampsia remote from term, thromboprophylaxis, appropriate fluid therapy, the role of prophylactic magnesium sulfate and anaesthetic issues for women with pre‐eclampsia. The guidelines stress the need for experienced team management for women with pre‐eclampsia and mandatory hospital protocols for treatment of hypertension and eclampsia. New areas addressed in the guidelines include recommended protocols for maternal and fetal investigation of women with hypertension, preconception management for women at risk of pre‐eclampsia, auditing outcomes in women with hypertensive diseases of pregnancy and long‐term screening for women with previous pre‐eclampsia.

Recommendations for the diagnosis and treatment of deep venous thrombosis and pulmonary embolism in pregnancy and the postpartum period

Venous thromboembolism (VTE) in pregnancy and the postpartum is an important cause of maternal morbidity and mortality; yet, there are few robust data from clinical trials to inform an approach to diagnosis and management. Failure to investigate symptoms suggestive of pulmonary embolism (PE) is a consistent finding in maternal death enquiries, and clinical symptoms should not be relied on to exclude or diagnose VTE. In this consensus statement, we present our recommendations for the diagnosis and management of acute deep venous thrombosis (DVT) and PE. All women with suspected DVT in pregnancy should be investigated with whole leg compression ultrasonography. If the scan is negative and significant clinical suspicion remains, then further imaging for iliofemoral DVT maybe required. Imaging should be undertaken in all women with suspected PE, as the fetal radiation exposure with both ventilation/perfusion scans and CT pulmonary angiography is within safe limits. Low‐molecular‐weight heparin (LMWH) is the preferred therapy for acute VTE that occur during pregnancy. In observational cohort studies, using once‐daily regimens appears adequate, in particular with the LMWH tinzaparin; however, pharmacokinetic data support twice‐daily therapy with other LMWH and is recommended, at least initially, for PE or iliofemoral DVT in pregnancy. Treatment should continue for a minimum duration of six months, and until at least six weeks postpartum. Induction of labour or planned caesarean section maybe required to allow an appropriate transition to unfractionated heparin to avoid delivery in women in therapeutic doses of anticoagulation.

Recommendations for the prevention of pregnancy-associated venous thromboembolism.

Pregnancy is a risk factor for venous thromboembolism (VTE), an important cause of maternal morbidity and mortality. Although there is a 4–5‐fold increased risk compared to that of nonpregnant women of the same age, the absolute risk is low at no more than two episodes of VTE per 1000 pregnancies. There is uncertainty about which women require thromboprophylaxis during pregnancy or postpartum because of a lack of data from appropriate clinical trials. For this reason, recommendations for prophylaxis should be made only after explaining the available evidence to the patient and taking into account her perception of the balance of risk and benefit in thromboprophylaxis. The aim of these recommendations is to provide clinicians with practical advice to assist in decisions regarding thromboprophylaxis in women considered to be at risk of VTE during pregnancy and the postpartum. The authors are clinicians from across New Zealand and Australia representing the fields of haematology, obstetric medicine, anaesthesiology, maternal–fetal medicine and obstetrics. Authors were invited to review the relevant literature and then worked collaboratively to devise recommendations and resolve areas of controversy. The recommendations contained herein were reached by consensus and represent the opinion of the panel. The absence of randomised clinical trials in this area limits the strength of evidence that can be used, and it is acknowledged that they represent level C evidence. The panel advocates for appropriate clinical studies to be carried out in this patient population to address the inadequacy of present evidence.

Interobserver variability in the measurement of fetal middle cerebral artery peak systolic velocity in a tertiary fetal medicine unit

To investigate the interobserver variability of fetal middle cerebral artery (MCA) peak systolic velocity (PSV) Doppler measurements in a tertiary fetal medicine unit.

Combining first and second trimester markers for Down syndrome screening: Think twice.

Aims: This study compares different screening strategies for the detection of Down syndrome and considers practical implications of using multiple screening protocols.

Precise mid-trimester placenta localisation: does it predict adverse outcomes?

A low‐lying placenta detected at the mid‐pregnancy ultrasound is commonly reported to warn against potential morbidity associated with placenta praevia. There is no information on what distance away from the internal cervical os is safe.

Re: Comparison between prenatal ultrasound and postmortem findings in fetuses and infants with developmental anomalies

In their study, Vogt et al.1 review retrospectively 455 autopsies of fetuses and infants with developmental abnormalities, as performed at Trondheim University Hospital, Norway, between 1995 and 2004. For each autopsy, the authors compare the postmortem findings with those yielded from the corresponding antenatal ultrasound scan. In order to do so, they measure the ‘agreement’ between the ultrasound and autopsy findings. Finally, the paper comments on the implications of this ‘agreement’, with reference to the utility of postmortem examinations for patients. The paper finds that of the 455 autopsies studied, only four (< 1%) yielded additional information that influenced patient counseling. Several specialists at the Women’s and Children’s Hospital (WCH), South Australia, were surprised by this low figure. This prompted us to conduct a brief analysis of our own autopsies in the past year. We reviewed the reports of 58 autopsies performed in 2012 following second-trimester terminations. We excluded terminations indicated for maternal health reasons, and ‘external only’ autopsies. Each case was examined and sorted according to whether the autopsy revealed new information or merely confirmed the findings of the antenatal ultrasound exam. This was determined in a case-by-case fashion. The data were further categorized according to whether or not the findings of the autopsy altered patient counseling. Findings were deemed to have influenced counseling if they changed an abnormality’s recurrence risk, if they led to a new diagnosis, or if they confirmed a diagnosis suggested hesitantly on ultrasound (but not if they confirmed one made confidently.) We found that 53% (31/58; 95% CI, 13%) of autopsies found significant new information and that 45% (26/58; 95% CI, 13%) affected counseling. This result differs significantly from that found by Vogt et al.1. Several different factors are hypothesized to contribute towards this marked discrepancy. Firstly, the two departments may have adopted different definitions: it is unknown precisely how the authors defined ‘influence patient counseling’. It is also not known what constituted ‘additional findings’. For example, perhaps if a diagnosis postulated tentatively in an antenatal ultrasound report were then to be corroborated definitively by postmortem findings, Vogt et al. would not consider the autopsy as having provided further information, whereas our team would. Furthermore, the WCH routinely makes use of numerous resources in its postmortem examination process, including magnetic resonance imaging, DNA microarray testing, histology and microbiology. When consent is obtained, the placenta and fetus are always examined grossly and histologically. In addition, every case is presented to at least one multidisciplinary advisory meeting. Vogt et al.1 do not disclose whether their autopsies feature more than general radiography and gross fetal examination. The paper concludes that, while antenatal imaging is rapidly improving, there are still cases in which postmortem findings alter the diagnosis and patient counseling. We agree with this conclusion; however, we posit that the extent to which this can be true may have been underrepresented by this study, especially when considering the scope of diagnostic facilities and multidisciplinary expertise available at specialist institutions like the WCH.