The May issue of Ultrasound in Obstetrics & Gynecology includes a study presenting an automated method for modelling second-to-third trimester placentae, a study assessing the value of pregnancy-associated plasma protein-A for preterm pre-eclampsia screening, a systematic review reporting the incremental yield of prenatal exome sequencing in phenotypically normal fetuses, a study assessing the ability of ultrasound examiners to detection infiltration of ovarian cancer, and a study comparing intrauterine transfusion techniques in hemolytic disease of the fetus and newborn.
Please see below a selection of articles from the May issue of the Journal chosen specially by the UOG team. To view all UOG content, become an ISUOG member today or login and upgrade.
Screening for pre-eclampsia using pregnancy-associated plasma protein-A or placental growth factor measurements in blood samples collected at 8–14 weeks' gestation
Pregnancy-associated plasma protein-A (PAPP-A) and placental growth factor (plGF) collected after 11 weeks are reliable markers for predicting the development of pre-eclampsia (PE) later in pregnancy, but there is limited evidence regarding their predictive performance in PE screening when collected before 10 weeks. Rode et al. investigated the value of PAPP-A collected before 11 weeks and PlGF collected at 8–14 weeks in screening for preterm PE, and found that PAPP-A did not significantly improve the detection rate. However, PlGF collected at or after 10 weeks increased the detection rate for preterm PE by 25.0% (95% CI, 4.3–44.4%) when combined with maternal factors, and by 16.4% (95% CI, 5.6–29.0%) when collected at 11–14 weeks and combined with maternal factors, mean arterial pressure and uterine artery pulsatility index, at a 10% screen-positive rate. While PlGF is of value at 10–14 weeks' gestation, there is no evidence to support the use of PAPP-A or PlGF in first-trimester PE screening when measured before 10 weeks' gestation.
Incremental yield of exome sequencing over standard prenatal testing in structurally normal fetuses: systematic review and meta-analysis
Since the development of prenatal exome sequencing (PES), it has become an emerging clinical practice in non-resource limited countries or those with or privately funded health services to perform PES in fetuses without a detected structural anomaly. Sotiriadis et al. conducted a systematic review and meta-analysis to determine the incremental yield of PES in phenotypically normal fetuses with a normal G-banded karyotype or chromosomal microarray. The pooled incremental yield was found to be 1.6% (95% CI, 1.0–2.6%), and the majority of variants (18/32) were de novo within genes associated with autosomal dominant inherited conditions (pooled incremental yield, 0.9% (95% CI, 0.5–1.7%)). The likelihood of a variant being associated with severe disease was 0.5% (95% CI, 0.1–1.5%). The authors conclude that further research is needed to develop a universal classification of disease severity and to apply this evidence in clinical practice.
Automated multivolume placental reconstruction using three-dimensional power Doppler ultrasound and infrared camera tracking
Recent developments have seen the evaluation of placental volumetric perfusion performed directly using power Doppler ultrasound (PD-US), however, by the second trimester, the size of the growing placenta exceeds the capacity of a single US volume. To overcome this limitation, Xue et al. developed a novel method that uses automated infrared camera tracking and multiple 3D PD-US volumes that were stitched to model the vasculature and structure of entire second-to-third-trimester placentae. The authors constructed a custom phantom whose dimensions accurately mimicked those of a term placenta, enabling a feasibility study; this included 17 women with an uncomplicated singleton pregnancy and 49 3D-US datasets, showing a 92% reconstruction success rate per placental volume set with 100% participant achievability. The verified accuracy and clinical feasibility of this model builds a foundation on which to develop a practical screening tool for detecting placental insufficiency and has the potential for widespread application to reconstruction of adult organs.
Comparison of intrauterine transfusion techniques in hemolytic disease of the fetus and newborn
Severe hemolytic disease of the fetus and newborn (HDFN) is a serious perinatal condition that can result in fetal demise or long-term neurological sequelae if not treated in early pregnancy; intrauterine transfusion (IUT) is the gold standard for treatment, but it carries a high risk of complications when performed at an early gestation. In this study, van ‘t Oever et al. conducted a comparison of IUT techniques, finding a lower rate of Hb level decline when using intrahepatic + intraperitoneal transfusion compared to intrahepatic transfusion alone, with a mean difference of 0.48 (95% CI, 0.29–0.66) g/dL/week, and a 5 day prolongation of the interval between IUT procedures. This slower decline may be beneficial in early-onset severe HDFN to bridge the gap until term gestation, however, the potential benefits should be weighed against the increased complexity and extended duration of the procedure on an individual basis.
Ultrasound examiners' ability to describe ovarian cancer spread using preacquired ultrasound videoclips from a selected patient sample with high prevalence of cancer spread
While ultrasound examination for the detection of infiltration of ovarian cancer is a viable alternative to computed tomography or magnetic resonance imaging, ultrasound quality and efficacy are operator dependent. Fischerova et al. evaluated the ability of 25 ultrasound examiners with different levels of ultrasound experience to correctly detect infiltration of ovarian cancer in predefined anatomical locations. The probability of correct classification ranged from 0.956 to 0.975, thus showing that examiners with a minimum of 6 months ultrasound training could correctly classify infiltration, when assessing preacquired videoclips obtained by an expert sonographer. Depending on the anatomical site, inter-rater agreement ranged from substantial to very good. However, the authors acknowledge that these results are likely to be overoptimistic and call for well-designed studies that evaluate the diagnostic accuracy and reliability of ultrasound for the estimation of ovarian cancer spread in clinical practice.