Impact of amniotic fluid “sludge” on the risk of preterm delivery

Objective: To evaluate the impact of amniotic fluid “sludge” (AFS) on the risk of preterm delivery and to describe the effect of antibiotic treatment in that situation.

Methods: Case–control study including singleton pregnancies with or without AFS, between 15–32 weeks of gestation. Factors associated with preterm delivery before 32 weeks, 34 weeks and 37 weeks were evaluated with univariate and multivariate logistic regression. Since all women with AFS in this study were treated with antibiotics, a historical comparison was performed with similar patients with AFS found before 2007 and not treated with antibiotics.

Results: AFS was observed in 90/1220 patients (7.4%). AFS was associated with shorter cervical length, greater body mass index, cervical cerclage and preterm birth before 28 weeks. However, after adjustment, AFS did not remain associated with preterm delivery before 32 or 34 weeks. The historical comparison suggested that azithromycin could significantly reduce the risk of preterm delivery before 34 weeks (odds ratio: 0.2; 95% CI: 0.04–0.92).

Conclusions: AFS, treated with azithromycin, was associated with a higher risk of prematurity, but not independently after adjustment for cervical length and second trimester vaginal bleeding. Further studies need to evaluate the effect of antibiotics in pregnancies with AFS.     

Three-dimensional versus two-dimensional ultrasound for fetal nasal bone evaluation in the second trimester

Objectives: To compare two-dimensional with three-dimensional ultrasound evaluation of the fetal nasal bone in the second trimester.

Methods: A prospective, non-interventional study was conducted, in 55 singleton fetuses, between 18 and 24 weeks’ gestation. Fetal nasal bone length was measured in the midsagittal plane by two-dimensional imaging and in the midsagittal and coronal plane with three-dimensional ultrasound. All three measurements were compared with one another using one-way repeated samples-measures ANOVA and paired samples t-test.

Results: The average fetal nasal bone length (mean?±?SD) as determined by the three methods was 7.01?±?0.94?mm for the two-dimensional midsagittal, 6.96?±?1.34?mm for the three-dimensional midsagittal, and 6.98?±?1.32?mm for the three-dimensional coronal plane; comparisons between one another were not statistically significant. Unilateral hypoplasia and bifid shape of the fetal nasal bone were detected in 8.2% and 20.4% of cases, respectively, by three-dimensional ultrasound, whereas all cases evaded detection with two-dimensional ultrasound (p?<?0.001 and p?=?0.001, respectively).

Conclusions: Fetal nasal bone length measured with two-dimensional ultrasound does not differ significantly from three-dimensional measurements. However, three-dimensional ultrasound is superior in detecting unilateral nasal bone hypoplasia or absence and in assessing fetal nasal bone shape. Hence, fetal nasal bone examination in the second trimester should include three-dimensional ultrasound evaluation.     

The utility of ultrasound in late pregnancy compared with clinical evaluation in detecting small and large for gestational age fetuses in low-risk pregnancies

Objective: To determine the utility of ultrasound (US) in late pregnancy for identifying fetuses with growth disturbances.

Methods: This study was designed as a retrospective study of birth weights over a 12-month period at the Royal Hobart Hospital (RHH) and Barwon Health (BH). Data were collected from the discharge summaries and medical records at both hospitals targeting abnormal fetal weight below 10th percentile (small for gestational age – SGA) and above 90th percentile (large for gestational age – LGA).

Results: There were 4079 study patients from both hospitals. After weight adjustment by gender and gestational age, an abnormal fetal weight was detected in 741 cases (babies over the 90th percentile or below 10th percentile). One hundred and twenty-eight patients with high-risk pregnancies were excluded. Therefore, a total of 613 patients remained that were considered to be low-risk pregnancies with abnormal foetal growth; 305 patients from RHH and 308 from BH. The antenatal detection rate for LGA was 35.9%, at RHH by combination of US and clinical evaluation, while for BH it was 34.8% by clinical evaluation alone (p?=?0.910). The antenatal detection rate for SGA was 36.8% via US and clinical evaluation at RHH and 54.5% by clinical evaluation alone at BH (p?=?0.006).

Conclusion: This study shows no benefit in the use of routine US for the antenatal diagnosis of LGA compared with clinical evaluation in low-risk pregnancies. US evaluation was inferior to clinical evaluation in the antenatal diagnosis of SGA in low-risk pregnancies.     

New technique for assessing fetal heart growth using three-dimensional ultrasonography: description of the technique and reference curves

Objective: To describe a new technique for assessing fetal growth using three-dimensional ultrasonography (3DUS) using the extended imaging virtual organ computer-aided analysis (XI VOCAL) software and its respective reference curves.

Methods: We conducted a cross-sectional study on 303 normal singleton pregnancies between their 20th and 34th weeks. To assess fetal heart growth, we used the XI VOCAL software with 10 planes in which the reference lines (beginning and end) were placed at the cardiac apex, the output level of the vessels and the base above the diaphragm, respectively. To assess the correlation between distance and interval, polynomial regressions were performed with adjustments using the coefficient of determination (R²). To assess the inter-observer reproducibility, we used the intraclass correlation coefficient (ICC).

Results: The mean distance between the apex and the base of the fetal heart ranged from 14.41?±?1.24?mm to 26.24?±?2.62?mm between the 20th and 34th weeks, respectively. The mean interval between the apex and the base of the fetal heart ranged from 1.56?±?0.13?mm and 2.94?±?0.30?mm between the 20th and 34th weeks, respectively. We observed good correlation of distance and interval with the gestational age, with R²?=?0.73 and 0.74, respectively. We observed a good inter-observer to the interval and distance with ICC?=?0.983 and 0.996, respectively.

Conclusion: We described a new technique for assessing fetal heart growth using 3DUS and determined reference curves for the distance and interval between the 20th and 34th weeks of pregnancy.     

Ultrasound evaluation of cortical brain development in fetuses with intrauterine growth restriction

Objective: We evaluated the ultrasound appearance of brain volume and cortical development in fetuses with early growth restriction and placental insufficiency.

Methods: We examined a cohort of 20 fetuses with severe intrauterine growth restriction (IUGR) and evidence of placental insufficiency by three-dimensional (3D) ultrasound between 24 and 34 weeks. We graded cortical development and measured the supratentorial intracranial volume. The cortical grading and volume were compared to data obtained from a reference population of 28 adequate for gestational age (AGA) fetuses.

Results: Ultrasound examinations were performed in 20 fetuses with IUGR. The biometry and brain volume were significantly reduced in IUGR fetuses. There was evidence of accelerated cortical development in IUGR fetuses.

Conclusion: This study confirms that the smaller brain volume in IUGR fetuses, with normal or accelerated cortical maturation as previously depicted with postnatal MRI examination, can be demonstrated by prenatal 3D ultrasound.     

Epidermoid cyst in intrapancreatic accessory spleen: A systematic review

Background/Objectives

Due to its rarity, epidermoid cyst in intrapancreatic accessory spleen (ECIPAS) is still a diagnostic dilemma during clinical practice. The aim of this review was to summarize the epidemiologic features and management of ECIPAS.

Microscopic observation of chemical modification in sections using scanning acoustic microscopy

A scanning acoustic microscope (SAM) calculates the speed of sound (SOS) through tissues and plots the data on the screen to form images. Hard tissues result in greater SOS; based on these differences in tissue properties regarding SOS, SAM can provide data on tissue elasticity. The present study evaluated whether tissue modifications, such as formalin fixation, periodic acid‐Schiff (PAS) reactions and protein degradation, changed the acoustic properties of the tissues and whether SAM could be a useful tool for following chemical changes in sections. The fixation process was observable by the increased SOS. During the PAS reaction, the glycosylation of tissues was characterized by an increased SOS. Mucous or glycogen distribution was visualized and was found to be statistically comparable among lesions and states. Protease digestion by pepsin led to a decreased SOS. Tissue sensitivity to proteases varied due to the stage, cause and duration of inflammation or ageing. Changes in acoustic properties were more sensitive than those in optical histology. SAM facilitates the visualisation of the time course or distribution of chemical modifications in tissue sections, thus aiding their comparison among tissues. SAM may be an effective tool for studying changes such as protein cross‐linkage, tissue repair and ageing.     

2D Dose Reconstruction by Artificial Neural Network for Pretreatment Verification of IMRT Fields

The use of intensity-modulated radiation therapy (IMRT) is developing rapidly in clinical routines. Because of the high complexity and uniqueness of IMRT treatment plans, patient-specific pretreatment quality assurance is generally considered a necessary prerequisite for patient treatment. In this work, we proposed a modified methodology of electronic portal imaging device (EPID)–based dose validation for pretreatment verification of IMRT fields by applying artificial neural networks (ANNs). The ANN must be trained and validated before use for pretreatment dose verification. For this purpose, 20 EPID fluence maps of IMRT prostate anterior-posterior fields were used as an input for ANN (feed forward type) and a dose map of those fluence maps that were predicted by treatment planning system as an output for ANN. After the training and validation of the neural network, the analysis of 10 IMRT prostate anterior-posterior fields showed excellent agreement between ANN output and dose map predicted by the treatment planning system. The average overall fields pass rate was 96.0% ± 0.1% with 3 mm/3% criteria. The results indicated that the ANN can be used as a low-cost, fast, and powerful tool for pretreatment dose verification, based on an EPID fluence map.