The June issue of Ultrasound in Obstetrics & Gynecology has a special focus on pre-eclampsia, with relevant articles on the prediction of pre-eclampsia using serum biomarkers, maternal hemodynamic indices, and models combining these with maternal factors. Other articles in this issue include an Editorial describing a new app for interactive multiplanar navigation through the fetal brain.

Please see below a selection of articles from the June issue of the Journal chosen specially by the UOG team. To view all UOG content, become an ISUOG member today or login and upgrade.

Pre-eclampsia (PE) is a major cause of maternal mortality and morbidity worldwide, with an estimated incidence of between 3% and 10% of all pregnancies. Poor placentation is known to play an important part in its pathophysiology and there is now compelling evidence that the maternal cardiovascular system may make an equally important contribution. An Opinion piece by Basky Thilaganathan discusses, in the context of articles in this issue of UOG, evidence on the involvement of the maternal cardiovascular system and the use of cardiovascular parameters in screening for PE.

Serum biomarkers
Poor placentation in women with PE has led to the finding that serum concentrations of angiogenic biomarkers such as soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) are altered in affected women. The evolution of the sFlt-1/PlGF ratio in women with suspected or confirmed PE was investigated in an Original Article by Saleh et al., finding that, in up to 10% of women admitted for evaluation with a low sFlt-1/PlGF ratio at initial assessment, the ratio may increase in subsequent weeks, suggesting that multiple measurements are required. It was also found that, in women with a high sFlt-1/PlGF ratio at admission, the ratio doubles every week and decreases rapidly postpartum towards healthy levels.

Women with PE experience cardiovascular alterations; as such, the heart of affected women produces cardiac damage biomarkers. An Original Article by Sabriá et al. investigated the addition of N-terminal pro-B natriuretic peptide to the sFlt-1/PlGF ratio for prediction of delivery with PE within 1 week in women with suspected PE and sFlt-1/PlGF ratio > 38, finding it to significantly improve prediction and reduce the high false-positive rate associated with the sFlt-1/PlGF ratio. This article is accompanied by a Referee Commentary by Stefan Verlohren, further discussing the importance of the findings. The prediction of development of severe PE/HELLP syndrome within 1 and 2 weeks by a combination of angiogenic and vasoactive biomarkers in the third trimester in women with mild to moderate PE was investigated in an Original Article by Lind Malte et al., finding sFlt-1 to perform similarly to or better than the sFlt-1/PlGF ratio in this population, and that C-terminal pro-endothelin-1 is a promising predictor, particularly in combination with sFlt-1 and systolic blood pressure. 

Maternal hemodynamics 
The strong predictive ability of uterine artery (UtA) Doppler for PE is commonly thought to be grounded in PE having a placental origin. An Original Article by Rodríguez et al. investigated the rate of placental apoptosis and adverse perinatal outcome in patients with late-onset PE and abnormal UtA Doppler at diagnosis, finding that UtA Doppler in late PE has a strong association with placental apoptosis and adverse perinatal outcome and may therefore be a useful technique for identifying PE with placental origin. This article is accompanied by a Referee Commentary by Karin Leslie in which the findings are discussed in relation to the ‘chicken and egg’ debate of PE as a maternal cardiovascular vs placental syndrome. This debate is touched upon in a Systematic Review by Kalafat et al. in which ophthalmic artery Doppler was investigated as an alternative to UtA Doppler and found to be a simple, accurate and objective technique with a standalone predictive value for the development of early-onset PE equivalent to that of UtA Doppler evaluation. The authors advise that elucidation is needed of the underlying mechanism by which two seemingly unrelated maternal vessels can be used for prediction of a disease commonly referred to as a placental disorder.

Combining predictors
The development of a sensitive screening model for PE has been at the forefront of research priorities for several decades. A screening algorithm was developed previously by The Fetal Medicine Foundation (FMF) to identify women at high risk for PE in order to investigate the effect of treatment with aspirin on preterm PE in these women, finding aspirin to be effective. An Original Article by Poon et al. compares screening using the FMF algorithm to that using criteria of the National Institute for Health and Care Excellence (NICE) and the American College of Obstetricians and Gynecologists (ACOG). It was found that, in women who are screen positive for preterm PE according to the ACOG or NICE criteria but screen negative according to the FMF algorithm, the risk of preterm PE is reduced to within or below background levels (download the accompanying Journal Club slides). The ‘screening programme for pre-eclampsia’ (SPREE) study by Tan et al. goes on to provide validation of the FMF algorithm for first-trimester PE screening, demonstrating poor performance of and compliance with NICE guidelines, but that screening using the FMF algorithm markedly improves screening performance, doubling sensitivity for preterm PE to 82%.

Also in this issue…
An Editorial by Ghi et al. describes a new app, ‘Fetal Brain Tutor 4us’, which was developed as a tool for interactive multiplanar navigation through the normal mid-gestational fetal brain. It utilizes ultrasound-derived images to create a three-dimensional virtual object which allows the user to select different scanning planes of the fetal brain and to scroll through each one. The authors propose the app as a teaching and self-study tool that may in the future be incorporated into ultrasound machines as an intelligent navigator. 



Coming up in the next issue of UOG…

  • An Original Article by Nicolaides et al. presents FMF birth-weight charts derived using a reference population of all babies at a given gestational age, including those still in utero. Preview the Earlyview article.
  • An ISUOG guideline on intrapartum ultrasound provides guidance to practitioners on when ultrasound in labor is clinically indicated and how sonographic findings may affect labor management.