The December issue of Ultrasound in Obstetrics & Gynecology includes a Randomized Controlled Trial on the sonographic diagnosis of fetal head position before vacuum extraction, a Systematic Review on metformin for the prevention of hypertensive disorders of pregnancy in women with gestational diabetes or obesity, an Original Article on the diagnostic yield of chromosomal microarray analysis in fetuses with isolated increased nuchal translucency, and an Original Article on maternal blood-pressure trends throughout pregnancy and development of pre-eclampsia in women receiving first-trimester aspirin prophylaxis.
Randomised Italian Sonography for occiput POSition Trial Ante vacuum (R.I.S.POS.T.A.)
Although successful in most cases, a 4–6% failure rate has been reported following attempted instrumental vaginal delivery by vacuum extraction, with fetal head malposition being among the main determinants of failure. In this Randomized Controlled Trial, Ghi et al. assessed whether sonographic diagnosis of fetal head position before instrumental delivery can reduce the risk of failed vacuum extraction and improve delivery outcome. It was found that rate of emergency Cesarean section due to failed vacuum delivery was not significantly different between women who underwent only digital assessment of the fetal head position and those who had both digital and sonographic assessment before the procedure. Maternal and perinatal outcomes were also comparable between the two groups.
Metformin for prevention of hypertensive disorders of pregnancy in women with gestational diabetes or obesity: systematic review and meta-analysis of randomized trials
While aspirin has been shown to reduce the risk of early-onset pre-eclampsia, an effective preventative method also targeting late-onset disease has yet to be established. Metformin, an anti-diabetic agent, may be able to prevent pre-eclampsia by stabilization of vasoactive mediators, improving cardiovascular function and limiting gestational weight gain. In this Systematic Review of randomized trials, Kalafat et al. investigated the association of metformin use with hypertensive disorders of pregnancy in women with gestational diabetes or obesity. Metformin was found to be associated with a high probability of preventing any hypertensive disorder of pregnancy when compared with other treatments.
Diagnostic yield of chromosomal microarray analysis in fetuses with isolated increased nuchal translucency: a French multicenter study
Recently, several studies have demonstrated the advantages of implementing chromosomal microarray analysis (CMA) in the prenatal setting. In fetuses with increased nuchal translucency thickness, CMA can detect about 4% of copy number variants (CNVs) not visible by karyotyping. In this Original Article, Egloff et al. determined the frequency and nature of CNVs identified by CMA in fetuses with isolated increased nuchal translucency thickness. The study demonstrates benefit of CMA in the etiological diagnosis of these fetuses, with most of the detected pathogenic CNVs being cryptic and around 2% of cases having a cryptic pathogenic CNV.
Maternal blood-pressure trends throughout pregnancy and development of pre-eclampsia in women receiving first-trimester aspirin prophylaxis
While initiation of first-trimester aspirin prophylaxis is associated with reduced risk of pre-eclampsia, it does not mitigate all predisposing risks. Higher blood pressure measured on a single occasion between 11 and 14 weeks is associated with an increased risk for pre-eclampsia, although whether this association is related to sustained blood-pressure trends across all trimesters rather than a single observation in the first trimester was not determined. In this Original Article, Baschat et al. monitored blood-pressure trends in pregnant women who initiated first-trimester aspirin, finding that those who develop pre-eclampsia have significantly and sustained higher blood pressure from the onset of pregnancy.
Coming up in the next issue of UOG…
- An ISUOG Guideline on the role of ultrasound in screening for and follow-up of pre-eclampsia. View the Early View article.
- A Systematic Review by Sotiriadis et al. on maternal and perinatal outcomes after elective labor induction at 39 weeks in uncomplicated singleton pregnancy. Preview the Accepted Article.
- An Original Article by McKanna et al. on a fetal fraction-based algorithm for non-invasive prenatal testing to screen for trisomies 13 and 18 and triploidy in women with low cell-free fetal DNA. View the Early View article.