Comparison of noninvasive prenatal screening with combined first-trimester screening as a frontline screening approach for common trisomies in a public hospital in Australia.

BACKGROUND: Combined first-trimester screening (cFTS) for fetal anomalies involves maternal serum screening for biochemical markers and measurement of the nuchal translucency (NT) by ultrasound. Noninvasive prenatal screening (NIPS) analyses cell-free DNA present in a maternal blood sample for presence of fetal chromosomal aneuploidies. AIMS: To compare NIPS with cFTS as frontline screening in a public hospital in Australia. MATERIALS AND METHODS: Women were offered NIPS in addition to the usual cFTS routinely offered to all women at a public hospital in NSW, Australia. The cFTS sample was collected at ten weeks' gestation and the NIPS sample at 12 weeks' gestation at the ultrasound appointment. RESULTS: In a low-risk population of 997 women, frontline NIPS had a screen-positive rate of 0.5% (5/997) vs 4.2% (42/997) with cFTS. cFTS correctly identified one trisomy 21 case and one trisomy 18 case; however, there were two trisomy 18 false negatives. Of five positive NIPS calls, four were correctly identified as trisomy 21 (one) and trisomy 18 (three); there were no NIPS false negatives. Overall, the false-positive rate with NIPS was 0.1% vs 4.0% by cFTS. CONCLUSIONS: The lower screen-positive rate with NIPS for common trisomies was a result of the significantly lower false-positive rate with NIPS. Consequently, NIPS as first-line screening, even if funded by the hospital, may provide cost savings. We believe NIPS should be used from ten weeks' gestation in conjunction with morphology ultrasound for routine first-trimester prenatal management.

Maternal diabetes independent of BMI is associated with altered accretion of adipose tissue in large for gestational age fetuses.

AIM: To analyse the effects of maternal diabetes mellitus (DM) and body mass Index (BMI) on central and peripheral fat accretion of large for gestational age (LGA) offspring. METHODS: This retrospective study included LGA fetuses (n = 595) with ultrasound scans at early (19.23 ± 0.68 weeks), mid (28.98 ± 1.62 weeks) and late (36.20 ± 1.59 weeks) stages of adipogenesis and measured abdominal (AFT) and mid-thigh (TFT) fat as surrogates for central and peripheral adiposity. Women were categorised according to BMI and DM status [pre-gestational (P-DM; n = 59), insulin managed (I-GDM; n = 132) and diet managed gestational diabetes (D-GDM; n = 29)]. Analysis of variance and linear regressions were applied. RESULTS: AFT and TFT did not differ significantly between BMI categories (normal, overweight and obese). In contrast, AFT was significantly higher in pregnancies affected by D-GDM compared to non-DM pregnancies from mid stage (0.44 mm difference, p = 0.002) and for all DM categories in late stage of adipogenesis (≥ 0.49 mm difference, p < 0.008). Late stage TFT accretion was higher than controls for P-DM and I-GDM but not for D-GDM (0.67 mm difference, p < 0.001; 0.49 mm difference, p = 0.001, 0.56 mm difference, p = 0.22 respectively). In comparison to the early non-DM group with an AFT to TFT ratio of 1.07, the I-GDM group ratio was 1.25 (p < 0.001), which normalised by 28 weeks becoming similar to control ratios. CONCLUSIONS: DM, independent of BMI, was associated with higher abdominal and mid-thigh fat accretion in fetuses. Use of insulin improved central to peripheral fat ratios in fetuses of GDM mothers.

Re-evaluating the role of cerebroplacental ratio in predicting adverse perinatal outcome.

AIM: This meta-analysis evaluates the use of cerebroplacental ratio (CPR) in predicting adverse perinatal outcome. METHODS: An electronic search of PubMed, Embase, Google scholar, Cochrane Library and Up-to-Date was done using variations of 'cerebroplacental ratio' and 'cerebroumbilical ratio'. We included studies where CPR was measured and postpartum outcomes were available. Selected articles were evaluated for quality of study methodology using the Newcastle-Ottawa Scale, and aggregate statistics for relative risks, odds ratios and 95% confidence interval were calculated. RESULTS: Data from 66,392 patients in 47 studies was extracted. There were 25 prospective, 17 retrospective and 5 case-control studies. Data on each obstetric or perinatal outcome was separately analysed. When analysing the prospective data, it showed abnormal CPR can predict the need for operative delivery due to foetal distress [RR: 2.52, 95%CI: 2.10-3.02; I2 = 65.78, P < 0.001], low pH [RR: 2.19, 95%CI: 1.01-4.75; I2 = 70.26, P = 0.005] and low Apgar score [RR: 2.05, 95%CI: 1.39-3.03; I2 = 37.15, P = 0.10], foetal or neonatal demise [RR: 2.49, 95%CI: 1.00-6.20], as well as NICU admission [RR: 2.23, 95%CI: 1.84-2.70; I2 48.53, P = 0.14].The retrospective data showed a statistically significant correlation in all outcomes but the low pH. CONCLUSION: Our meta-analysis shows that CPR can be used to identify foetuses with higher risk of operative delivery due to foetal distress, low Apgar score, NICU admission, neonatal morbidity as well as stillbirth and neonatal death rates.

Screening the second-trimester fetal heart in women with an increased body mass index using three-dimensional volume sweep.

PURPOSE: To determine the percentage of fetal cardiac anatomy as detailed in the International Society of Ultrasound in Obstetrics and Gynecology Practice Guidelines on sonographic screening examination of the fetal heart, which can be visualised in women with a body mass index (BMI) >30 kg/m2 using three-dimensional (3D) volume sweeps. METHODS: 3D volumes of the fetal heart were taken prospectively in 40 fetuses during routine second-trimester fetal anatomy scan. Scans and 3D volume sweeps were performed by two experienced sonographers and two experienced raters interpreted the 3D data. 3D volume acquisitions and post-processing analysis were performed according to the techniques described by Weissmann-Brenner et al. RESULTS: The two raters were able to detect an average of 12.9 and 14.1 of the 16 parameters in the 40 patients. Agreement between raters for the 16 parameters had an average of 80%. Five parameters (stomach, situs, heart occupies a third of thoracic area, majority of heart in the left chest and cardiac axis) were detected by both raters on all patients. The range of agreement was between 40% and 100%. The three-vessel view and bifurcation had agreement <60%. CONCLUSION: Consistent identification of all views of the fetal heart was not achieved using the simple method described in women with a BMI > 30 kg/m2.

Sonographic diagnosis of spontaneous uterine rupture at the site of cornual wedge resection scar - a case report.

Introduction: Uterine rupture and uterine dehiscence during pregnancy are known complications of a scarred uterus. Spontaneous uterine rupture at the site of prior cornual wedge resection has been previously reported in the literature, however remains rare. Discussion: We present a case of uterine rupture at 30 weeks gestation. This woman had previous right sided interstitial pregnancy treated with uncomplicated laparoscopic cornual wedge resection at eight weeks gestation. The index pregnancy occurred eight months after surgery. An emergency ultrasound prompted by non-specific abdominal pain and tenderness at 30 weeks gestation enabled diagnosis of uterine dehiscence. At emergency caesarean section four hours later full thickness wall rupture and haemoperitoneum were found. Surgical intervention resulted in a good outcome for both mother and baby. Conclusion: A brief account on uterine rupture in late pregnancy and relevant sonographic features related to this case are presented. This case demonstrates the value of ultrasound in the assessment of subtle clinical signs and symptoms in patients at risk of uterine rupture.

A futuristic vision of pocket ultrasound machines: watch this space.

Introduction: Australian medical ultrasound started in 1959 with the establishment of the Ultrasonics Institute. Since then the technology has advanced tremendously. We are now not only able to obtain clearer images on high specification ultrasound machines but also on pocket-sized ultrasound machines that are compact, lightweight and affordable. Method: The following descriptive review will examine the indication for use of pocket ultrasound machines in different clinical settings as well as provide evidence of its image clarity and accuracy. Potentially eligible studies were sought primarily through searches of the electronic databases PubMed, Medline (1996-Present), Embase (1996-Present) and Cochrane Library. Conclusion: Pocket ultrasound machines, with appropriate ultrasound knowledge and training, can be incorporated successfully in patient management. The addition of point-of-care ultrasound has been shown to improve management recommendations and outcomes.

The effect of preliminary training on quantitative evaluation of sonographer performance in the fetal morphology ultrasound examination.

Introduction: The aim of this study is to provide a quantitative scoring system to assess sonographer performance by reviewing images from the fetal morphology examination. Methods: Ten ultrasound images from patients at 18-22 weeks gestation were assessed and scored for quality according to predefined criteria. One hundred normal cases were randomly selected and 10 images from each case were analysed by four experienced reviewers. The preliminary training incorporated the first 25 cases and involved a training period for reviewers; the remaining 75 cases were allocated to post training. The scores acquired by each reviewer were statistically analysed using Pearson's and intra-class correlations to determine the reproducibility of the results. Results: The preliminary training results were calculated separately and compared to the post training study. The preliminary intra-class correlation coefficient was 0.12. In the post training study the intra-class correlation coefficient was doubled at 0.24. The greatest correlation was observed between reviewers 1 and 4 with a coefficient of 0.71. Reviewers 3 and 4 demonstrated the lowest correlation coefficient of 0.30. Discussion: A significant increase in the intra-class correlation coefficient indicated that training reviewers achieves more reproducible results. Suggested improvements to the study include recording fetal position, maternal BMI and assessing individual reviewer variability. An instruction manual defining each criterion might also yield better results. Conclusion: The quantitative method used in this study assessed ultrasound images by placing a numerical value on image quality. Analysis of the preliminary training period demonstrates improved reproducibility of the results. Further investigation into the criteria is necessary to refine the quantitative method.

Comparison of maternal abdominal subcutaneous fat thickness and body mass index as markers for pregnancy outcomes: A stratified cohort study.

BACKGROUND: Obesity in pregnancy is associated with a number of adverse outcomes. The effects of central versus general obesity in pregnancy have not been well established. AIM: To compare subcutaneous fat thickness (SFT) with body mass index (BMI) as a marker for pregnancy outcomes. METHODS: A stratified retrospective cohort study was performed on 1200 pregnancies, selected from a total of 4862 nulliparous, nonsmoking women between 2006 and 2010. SFT was measured on routine ultrasound at 18-22 weeks gestation. BMI and SFT measurements were compared for estimating risks for obesity-related pregnancy outcomes using logistic regression adjusted for maternal age. RESULTS: The median SFT was 18.2 mm (range 6.3-50.9 mm), the median BMI was 23.8 kg/m(2) (range 15.2-52.5), and the correlation between SFT and BMI was 0.53. For every 5 mm increase in SFT and every 5 kg/m(2) increase in BMI, the odds ratios for developing gestational diabetes mellitus were 1.40 (CI 1.22-1.61, P < 0.001) and 1.16 (CI 0.95-1.40, P = 0.1), for caesarean section 1.28 (CI 1.16-1.40, P < 0.001) and 1.16 (CI 1.05-1.28, P = 0.003), large for gestational age 1.28 (CI 1.16-1.47, P = 0.001) and 1.10 (CI 0.95-1.28, P = 0.16) and cumulative adverse obesity-related pregnancy outcomes 1.16 (CI 1.10-1.28, P = 0.002) and 1.05 (CI 0.95-1.16, P = 0.45), respectively. CONCLUSION: SFT at 18-22 weeks gestation is better than BMI as a marker for obesity-related pregnancy outcomes. As SFT is considered a surrogate measure for visceral fat, these results suggest that central obesity is a stronger risk factor than general adiposity in pregnancy.