The May issue of Ultrasound in Obstetrics & Gynecology includes an Opinion presenting ultrasound images of fetal abnormalities before 11 weeks, a ‘How to’ article on performing lung ultrasound in pregnant women with suspected COVID-19, a study assessing the impact of the Growth Assessment Protocol program on stillbirth rate in over 11 million births, and a study on whether cell-free DNA testing should be used in pregnancy with increased fetal nuchal translucency. Also online this month are new ISUOG Practice Guidelines on the role of ultrasound in the diagnosis and management of congenital infection, and updated Interim Guidance on COVID-19 during pregnancy and puerperium.
Sonographic detection of fetal abnormalities before 11 weeks of gestation
The unprecedented uptake and rapid clinical introduction of cell-free DNA (cfDNA) analysis have led to an increasing uptake of pretest ultrasound scans performed at 6–10 weeks of gestation, which creates a window of opportunity for early screening and diagnosis of fetal anatomical defects by experienced ultrasound specialists. In this article, Rolnik et al. illustrate 2D and 3D ultrasound images of pregnancies with fetal abnormality identified between 6+0 and 10+6 weeks of gestation, including those of the central nervous system, spine, heart, abdominal wall, urinary tract and limbs. Early ultrasound screening can provide a definitive diagnosis in cases with certain fetal defects, while in others a defect may be suspected and require confirmation later in pregnancy. In cases with a suspected defect, it may be appropriate that counseling is in favor of discouraging cfDNA testing with re-evaluation of fetal anatomy at 11–14 weeks and consideration of definitive genetic testing.
How to perform lung ultrasound in pregnant women with suspected COVID-19
Under certain circumstances, such as during the current COVID-19 outbreak, pregnant women can be a target for respiratory infection, and lung examination may be required as part of their clinical evaluation, ideally while avoiding exposure to radiation. Moro et al. propose a practical approach for obstetricians/gynecologists to perform lung ultrasound examination, discussing potential applications, semiology and practical aspects. Pathological ultrasound patterns were compared to those expected in a normal lung, with particular emphasis on those more indicative of COVID-19 disease. This approach could be of particular importance in emergency situations, such as the current pandemic infection of COVID-19. Watch the accompanying ‘How To’ video:
UK stillbirth trends in over 11 million births provide no evidence to support effectiveness of Growth Assessment Protocol program
Use of the Growth Assessment Protocol (GAP) program has increased internationally under the assumption that it reduces the stillbirth rate. On the basis that widespread implementation of GAP in England and Wales predated any implementation in Scotland, and as the health services are otherwise similar between the two regions, Iliodromiti et al. assessed the assertion that implementation of GAP leads to a reduced stillbirth rate by comparing the stillbirth trends between England/Wales and Scotland. A decline in stillbirth rate was observed in England and Wales, which coincided with implementation of the GAP program. However, a concurrent decline in stillbirth rate was observed in Scotland in the absence of increased implementation of GAP. The authors therefore conclude that further implementation of the GAP program and use of customized growth centiles is not warranted on the basis of their findings (read the press release).
Should cell-free DNA testing be used in pregnancy with increased fetal nuchal translucency?
With the introduction of fetal cell-free DNA (cfDNA) as a screening test for fetal aneuploidy, the utility of the components of first-trimester combined screening, such as nuchal translucency (NT) measurement, has been challenged. Miranda et al. assessed the frequency of atypical chromosomal and submicroscopic anomalies, as well as fetal structural abnormalities, observed on first-trimester ultrasound scan in fetuses with NT thickness >99th centile, in order to evaluate the suitability of using standard cfDNA testing as the sole screening test in these pregnancies. It was found that cfDNA does not appear to be the appropriate genetic test in fetuses with NT >99th centile, given that it would miss 12–19% of genetic anomalies in this group. Additionally, first-trimester ultrasound will identify a major structural abnormality in 11% of the fetuses with NT >99th centile and no genetic anomaly (view the accompanying Journal Club slides).
Also online this month…
Updated Interim Guidance on SARS-CoV-2 infection during pregnancy and puerperium.
ISUOG Practice Guidelines: role of ultrasound in congenital infection
Ultrasound examination is key in the diagnosis and management of congenital infection. New ISUOG Practice Guidelines on the role of ultrasound in congenital infection discuss the ultrasound signs and the prognostic value of ultrasound findings. Six types of infection and their causative agents are looked at in detail: cytomegalovirus, Toxoplasma, parvovirus B19, rubella virus, varicella-zoster virus (which causes chickenpox) and Zika virus. For each, the ultrasound signs, timing of infection in relation to gestational age and diagnosis of maternal and fetal infection are discussed, and a brief outline of appropriate management is provided.
Coming up next month…
- An Opinion piece discussing the current evidence regarding intrauterine vertical transmission of SARS-CoV-2. Preview the Accepted Article.
- A Systematic Review and accompanying Editorial on the learning curves of different fetal spina bifida closure techniques.
- A study and accompanying Editorial on the reasons for a missed diagnosis of congenital heart defect on prenatal ultrasound.