The April issue of Ultrasound in Obstetrics & Gynecology includes a systematic review evaluating the safety and effectiveness of prenatal valacyclovir therapy in prevention and treatment of congenital cytomegalovirus infection, a large population-based study investigating the link between birth-weight centile and school performance, a prospective longitudinal study providing reference ranges for uterine artery pulsatility index across gestation and a Delphi consensus study focusing on ultrasound in the prenatal evaluation and management of patients at high risk of placenta accreta spectrum at delivery.

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

Effectiveness and safety of prenatal valacyclovir for congenital cytomegalovirus infection: systematic review and meta-analysis

The role of valacyclovir therapy in preventing and treating congenital cytomegalovirus (CMV) infection and reducing the risk of the associated adverse outcomes has been controversial. The new UOG systematic review and meta-analysis by D’Antonio et al. presents the latest evidence on the topic. The study demonstrates that, in pregnancies with primary maternal CMV infection, prenatal valacyclovir reduces the risk of vertical transmission of CMV, particularly in the first trimester of pregnancy, and increases the likelihood of asymptomatic infection. The treatment is associated with severe adverse events in a small proportion of women (3% in this study), which resolve after drug discontinuation. Future studies are required to establish whether prenatal valacyclovir reduces the risk of fetal structural anomalies and neurocognitive impairment in cases with confirmed congenital CMV infection. However, the efficacy of valacyclovir in preventing infection supports the potential value of universal prenatal screening for CMV.

Birth-weight centile at term and school performance at 12 years of age: linked cohort study

Little is known about the associations of fetal growth and birth weight with the long-term development of cases that are conventionally considered appropriate-for-gestational age (AGA, birth weight between the 10th and 90th centiles). In this population-based cohort study of 266,440 liveborn singletons, Burger et al. demonstrate that birth-weight centile is associated positively with school performance at 12 years of age across the entire birth-weight spectrum and that many of those classified as AGA, with birth weight up to the 76th–80th centiles, are still at increased risk of lower school performance. These findings highlight the need for better tools to identify fetuses with growth restriction and estimate the risk of long-term adverse outcome.

Reference ranges of uterine artery pulsatility index from first to third trimester based on serial Doppler measurements: longitudinal cohort study

Uterine artery pulsatility index (UtA-PI) is a key metric required in the assessment of maternal and fetal wellbeing. In this study, Cavoretto et al. used high-quality prospective longitudinal data of a low-risk population to derive reference ranges of the mean UtA-PI between 10 + 0 and 39 + 0 gestational weeks, using the rigorous methodology proposed by the INTERGROWTH-21st Project. These reference ranges may be useful in the assessment of low-risk populations and in the context of screening for pre-eclampsia, fetal growth restriction and other pathologies. However, external validation of the proposed reference ranges is warranted to confirm their value in predicting pregnancy outcome.

Modified Delphi study of ultrasound signs associated with placenta accreta spectrum

Prenatal diagnosis of placenta accreta spectrum (PAS) reduces the risk of morbidity and mortality associated with the disorder. Jauniaux et al. present the results of a Delphi study in which 37 experts were surveyed on the role of old and new ultrasound signs of PAS. The study confirms the value of seven established standardized ultrasound signs of PAS, including loss of the ‘clear zone’, myometrial thinning, bladder-wall interruption, placental bulge, uterovesical hypervascularity, placental lacunae and bridging vessels. It also corroborates the importance of performing a transvaginal ultrasound examination to establish the placental position and anatomy of the cervix when screening for PAS. No consensus was reached with regard to the eight new ultrasound signs identified as part of the systematic review. Future studies should evaluate whether these new signs of PAS can be useful in the prenatal evaluation and management of high-risk patients.

Coming up next month…

  • A systematic review and meta-analysis comparing perinatal outcome following early vs late selective termination in dichorionic twin pregnancies. Preview the Accepted Article.
  • A prospective study assessing the prevalence of deep and ovarian endometriosis in women attending a general gynecology clinic. Preview the Accepted Article.
  • A secondary analysis of prospectively collected data evaluating the performance of fetal fibronectin and cervical length in predicting spontaneous preterm birth in asymptomatic high-risk women with cervical cerclage. Preview the Accepted Article.