The October issue of Ultrasound in Obstetrics & Gynecology includes a systematic review and meta-analysis providing the most up-to-date evidence on the performance of the sliding sign for detecting pouch of Douglas obliteration and bowel involvement in patients with endometriosis, the first study to investigate the diagnostic yield of whole-genome sequencing for non-immune hydrops fetalis, a study investigating the optimal method for selective fetal reduction in complicated monochorionic pregnancies, and a study evaluating the diagnostic test accuracy of magnetic resonance imaging and pelvic floor ultrasound for diagnosis of levator ani muscle avulsion. Additionally, the October issue features the latest research on the impact of pre-eclampsia on the maternal brain, including its detrimental effects on functional organization of the brain and integrity of the blood–brain barrier, detectable years after the complicated pregnancy.

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

Diagnostic accuracy of sliding sign for detecting pouch of Douglas obliteration and bowel involvement in women with suspected endometriosis: systematic review and meta-analysis

In patients with endometriosis, pouch of Douglas obliteration and bowel involvement increase the duration and complexity of surgery, highlighting the importance of timely preoperative detection of these complications. Alcázar et al. present a systematic review and meta-analysis on the diagnostic performance of the sliding sign on transvaginal ultrasound in women with suspected deep endometriosis, reporting pooled sensitivity of 88% and 81% and pooled specificity of 94% and 95% for detecting pouch of Douglas obliteration and bowel involvement, respectively. Such high performance demonstrates that the sliding sign is an excellent tool for detecting pouch of Douglas obliteration and bowel involvement and confirms the fundamental role of transvaginal ultrasound as a diagnostic technique in women with suspected endometriosis.

Diagnostic yield using whole-genome sequencing and in-silico panel of 281 genes associated with non-immune hydrops fetalis in clinical setting

Although around 50% of non-immune hydrops fetalis (NIHF) cases are caused by chromosomal aberrations, the etiology of a large proportion of the remaining cases is unknown. In their new study, Westenius et al. investigate the value of clinical whole-genome sequencing in prenatally diagnosed NIHF cases without chromosomal aberrations, demonstrating an incremental diagnostic yield of 52%. Most of the causative variants were found in the HRAS gene, highlighting Costello syndrome as an important cause of NIHF. These findings suggest that whole-genome sequencing could be an effective first-line test for NIHF, with a diagnostic yield being as high as 75% when including cases with chromosomal and non-chromosomal abnormalities.

Perinatal and neurodevelopmental outcome in complicated monochorionic pregnancy after selective fetal reduction: radiofrequency ablation vs microwave ablation

Monochorionic pregnancy can be associated with serious complications, including twin-to-twin transfusion syndrome, twin reversed arterial perfusion sequence, twin anemia–polycythemia sequence and selective intrauterine growth restriction. Selective fetal reduction may be employed to target these complications. The study by Wu et al. compares the outcome following microwave ablation (MWA) and radiofrequency ablation for selective fetal reduction of complicated monochorionic pregnancy. While their results suggest similar survival rate and neurodevelopmental outcome associated with the two procedures, MWA appears to have an advantage of a reduced risk of preterm birth. The study also demonstrates that some procedure-related factors, such as indication, number of ablation cycles and gestational age at procedure, have a significant impact on perinatal outcome, which may help obstetricians and patients make better-informed decisions about such intervention.

Functional connectivity of limbic system and prefrontal cortex years after pre-eclampsia: 7-Tesla functional magnetic resonance imaging study

Compared with their normotensive counterparts, formerly pre-eclamptic women appear to be at higher risk of psychological symptoms and cognitive complaints following pregnancy. The new functional magnetic resonance imaging study by Canjels et al. demonstrates that women with a history of pre-eclampsia also have alterations in the local functional organization of the limbic system and prefrontal cortex, which are detectable years after the index pregnancy. Given that these brain regions play a distinct role in cognition and emotion, future studies should examine the relationship between the reported subjective complaints and the observed functional brain network changes in women with a history of pre-eclampsia and investigate how these brain changes can be treated.

Diagnostic test accuracy of magnetic resonance imaging and pelvic floor ultrasound for diagnosis of levator ani muscle avulsion

Levator ani muscle (LAM) avulsion occurs in 13–36% of women during their first vaginal delivery, putting them at an increased risk of pelvic organ prolapse and cystocele recurrence. Early detection of LAM avulsion may help identify at-risk women and inform treatment strategy. Magnetic resonance imaging (MRI) is currently considered to be the reference standard for LAM avulsion diagnosis, but ultrasound is also appealing as a less expensive and more widely available diagnostic option. The new study by van Gruting et al. compares the diagnostic performance of MRI and pelvic floor ultrasound for LAM avulsion in a general parous population. Their results show that ultrasound has lower sensitivity but higher specificity for LAM avulsion compared with MRI. MRI and endovaginal ultrasound have high predictive values for major LAM avulsion, while transperineal ultrasound has high predictive values for minor LAM avulsion. The authors conclude that pelvic floor ultrasound can be implemented as a triage test to assess parous women for LAM avulsion, but it cannot substitute for MRI. A positive test should be confirmed by a different observer or imaging technique.

Coming up next month…

  • A systematic review and meta-analysis comparing transvaginal ultrasound vs magnetic resonance imaging for preoperative staging of myometrial and cervical invasion in patients with endometrial cancer. Preview the Accepted Article.
  • A State-of-the-Art Review on sFlt-1 and PlGF in screening, prediction, diagnosis and monitoring of pre-eclampsia and fetal growth restriction. Preview the Accepted Article.

A selection of studies on open spina bifida, including:

  • A study evaluating white matter changes on diffusion tensor imaging and their association with ambulatory skills in infants with open neural tube defect. Preview the Accepted Article.
  • A prospective study comparing outcome following primary skin closure vs patch-based repair for spina bifida. Preview the Accepted Article.
  • A study investigating the efficacy of watertight fetal spina bifida aperta repair in achieving neuroprotection in the fetal lamb model of the disease. Preview the Accepted Article.