The October issue of Ultrasound in Obstetrics & Gynecology contains the latest research on the procedure-related risk of miscarriage following amniocentesis or chorionic villus sampling, including a cohort study and Systematic Review providing updated estimates of this risk. Articles on other topics include studies on the effect of sildenafil treatment on neonatal pulmonary hemodynamics and lung function in lambs with diaphragmatic hernia, the value of assessment of fetal head descent during active pushing before operative vaginal delivery, and the association between early-pregnancy events and subsequent antenatal, delivery and neonatal outcomes.
Risks of miscarriage following amniocentesis or chorionic villus sampling
The procedure-related risks of miscarriage following amniocentesis or chorionic villus sampling (CVS) quoted by professional bodies are varied and there is considerable evidence suggesting that these estimates are overstated. Beta et al. estimated the procedure-related risks of miscarriage following CVS and amniocentesis in a large cohort of women. It was found that the risks were much lower than those cited currently. This study along with 14 others were included in a Systematic Review by Salomon et al., which aimed to provide an updated estimate of the risk of miscarriage following these procedures. The risk was similarly found to be lower than that quoted currently and it was not significantly increased over the background risk. View the accompanying Journal Club slides and video abstract:
Also on this topic is an Opinion by Navaratnam and Alfiveric, discussing some of the methodological issues that they faced when meta-analyzing the procedure-related risks of amniocentesis and CVS. Topics discussed include which control data to use, whether to use fixed or random effects and whether to pool results.
Articles on other topics
Antenatal sildenafil treatment improves neonatal pulmonary hemodynamics and gas exchange in lambs with diaphragmatic hernia
In congenital diaphragmatic hernia, abdominal organs herniate into the thorax during embryogenesis, interfering with fetal lung development and resulting in severe pulmonary hypoplasia. While antenatal sildenafil treatment has been shown to attenuate abnormal pulmonary vascular and alveolar development in animal congenital diaphragmatic hernia models, it is unclear if this translates into improved pulmonary hemodynamics after delivery. Kashyap et al. evaluated the effect of antenatal sildenafil on neonatal pulmonary hemodynamics and lung function in lambs with diaphragmatic hernia. Sustained maternal antenatal sildenafil infusion was found to reduce pulmonary arterial pressure and increase pulmonary blood flow for the first 120 min after birth, which is consistent with the previously reported improvements in pulmonary vascular structure.
Descent of fetal head during active pushing: secondary analysis of prospective cohort study investigating ultrasound examination before operative vaginal delivery
While descent of the fetal head is considered to be predictive of successful vaginal delivery, evidence of this has not been documented and its predictive value is not mentioned in guidelines. Kahrs et al. investigated if fetal head descent assessed using transperineal ultrasound during active pushing is associated with duration of operative vaginal delivery, mode of delivery and neonatal outcome in nulliparous women with prolonged second stage of labor. Minimal or no fetal head descent was found to be associated with longer duration of operative vaginal delivery and higher frequency of Cesarean section.
Early-pregnancy events and subsequent antenatal, delivery and neonatal outcomes: prospective cohort study
While women with pelvic pain and/or vaginal bleeding in early pregnancy are not considered to be a high-risk group that warrants closer surveillance, there is evidence that these symptoms may be associated with subsequent complications including fetal growth restriction and preterm birth. Al-Memar et al. assessed prospectively the association between early-pregnancy events and the incidence of later adverse pregnancy outcomes. It was found that there is an increased incidence of antenatal complications in women experiencing pelvic pain and/or vaginal bleeding in the first trimester, and vaginal bleeding was associated with an increased incidence of neonatal complications.
Coming up in the next issue…
- A Systematic Review by di Pasquo et al. on non-visualization of the fetal gallbladder by ultrasound in the second trimester. Preview the Accepted Article.
- An Original Article by Le Bras et al. on the cost-effectiveness of five screening strategies for trisomies and other unbalanced chromosomal abnormalities. Preview the Accepted Article.