The February issue of Ultrasound in Obstetrics & Gynecology includes a systematic review evaluating adverse perinatal outcome in dichorionic twin pregnancy complicated by selective fetal growth restriction, a study deriving chorionicity-specific reference ranges for fetal growth in twin pregnancy, an analysis of emergency Cesarean delivery in placenta previa and placenta accreta spectrum and an evaluation of the diagnostic test accuracy of a standardized transvaginal examination for deep endometriosis of the uterosacral ligaments and torus uterinus.

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

Selective fetal growth restriction in dichorionic diamniotic twin pregnancy: systematic review and meta-analysis of pregnancy and perinatal outcomes 

There is limited evidence on the outcome of dichorionic twin pregnancies complicated by selective fetal growth restriction (sFGR), and clinical guidelines recommend untailored management akin to that for growth-restricted singletons. This systematic review and meta-analysis by D’Antonio et al. investigates the risk of adverse perinatal outcome in dichorionic twin pregnancies with sFGR compared to uncomplicated dichorionic twins. They report a 5-fold higher risk of perinatal death and a 3-fold higher risk of composite morbidity or admission to a neonatal intensive care unit in pregnancies with vs without sFGR. These findings should prompt a reassessment of the clinical guidance and encourage prospective research on this patient group to improve antenatal surveillance, counseling and management.

Fetal Medicine Foundation charts for fetal growth in twins 

It is accepted that twin gestations have divergent growth trajectories compared with singletons, but whether twin-specific growth charts are necessary to avoid overdiagnosis of growth restriction remains a matter of debate. In this study, Wright et al. derive chorionicity-specific reference distributions of estimated fetal weight in twin pregnancy. Fetuses from twin pregnancies tended to be smaller than singletons in the early second trimester, underwent a period of catch-up growth until 24 weeks, and then showed reduced growth that became more pronounced with advancing gestational age. The authors contend that singleton growth charts should be used uniformly as a standardized benchmark for fetal growth in all pregnancies, and that supplementation with twin-specific reference ranges enables comprehensive growth assessment in twin pregnancy. 

Determinants of emergency Cesarean delivery in pregnancy complicated by placenta previa with or without placenta accreta spectrum disorder: analysis of ADoPAD cohort 

If not suspected antenatally, placenta previa and placenta accreta spectrum disorder are associated with a high burden of maternal morbidity and mortality, and often necessitate emergency Cesarean delivery due to antepartum hemorrhage. In a secondary analysis of a large multicenter prospective study, the ADoPAD Study Group report that emergency Cesarean delivery occurred in 20% of women with placenta previa and placenta accreta spectrum and 30% of those with placenta previa only, and that both groups experienced more complications compared to women delivering by elective Cesarean. None of the maternal, pregnancy or ultrasound characteristics tested in a multivariate analysis was found to be predictive of emergency Cesarean delivery. The authors stress that identifying new prenatal sonographic predictors of this outcome should be a priority for future research in this patient group.

Prospective diagnostic test accuracy of transvaginal ultrasound posterior approach for uterosacral ligament and torus uterinus deep endometriosis 

Although the diagnosis of endometriosis has become increasingly imaging-based, transvaginal ultrasound continues to show limited accuracy in diagnosing deep endometriosis in its most common location: the uterosacral ligaments. In this prospective study, Freger et al. evaluate the diagnostic test accuracy of a standardized transvaginal assessment, with the probe placed in the posterior vaginal fornix, for deep endometriosis of the uterosacral ligaments and torus uterinus. Using surgical visualization as the reference standard, they report accuracy, sensitivity and specificity in the range of 75-100%, representing an improvement over previous studies. While these findings require external validation, they demonstrate the value of a standardized approach in assisting a notoriously elusive diagnosis.

Coming up next month…

  • A systematic review on the diagnostic yield of prenatal exome sequencing in agenesis of the corpus callosum. Preview the Accepted Article
  • A study comparing singleton vs twin growth charts in the prediction of neonatal morbidity in twin pregnancy. Preview the Accepted Article
  • A prospective study evaluating the performance of the updated M6 model in pregnancy of unknown location. Preview the Accepted Article.
  • A prospective study assessing a new machine-learning model for predicting first-trimester pre-eclampsia in a Latin American population. Preview the Accepted Article