Abdomen

The abdomen constitutes that part of the body between the thorax and the pelvis. The abdominal cavity is bounded by the diaphragm above but is contiguous with the pelvis; the boundary is defined by the bony landmarks of the pelvic bones and lumbar spine. Anteriorly and laterally, the abdominal cavity is bounded by the soft muscular and fascial tissues of the anterior abdominal wall; posteriorly, the wall is more rigid, being formed by the parietal peritoneum that lies over the vertebral bodies with their muscular attachments. From a functional perspective, the abdominal cavity essentially acts as a repository for a number of organ systems responsible for metabolic processing. This includes the hollow tubular structure of the bowel, which enters cranially at the gastro-oesophageal sphincter and develops into the remaining parts of the digestive system, carrying and processing nutrients and waste before, at the caudal end, passing these products back to the external environment. Organ systems such as the liver and kidneys are developed through a number of embryologic stages bringing a variety of different cell lines together for functional effect. Other structures that pass through the diaphragm and run into the pelvis include the great vessels, lymphatics and peripheral nerves. Although prenatal assessment of the abdomen may not inspire clinicians as much as some other structures, this is the powerhouse of metabolic well-being and includes and is bounded by many complex structures that need to be coordinated with surrounding tissues. Abnormalities of these systems can be lethal or cause significant morbidity in a neonate, and there is significant value in prenatal diagnosis that allows timely and appropriate intervention after birth

The optimal age for childbearing

Introduction: In Australia there is a growing trend for women to give birth later in life. In 2013 the average age of all women who gave birth was 30.1 years, compared with 29.5 years in 2003. The average age of women having their first baby also increased from 27.8 to 28.6 over this ten-year period. More significantly, the proportion of mothers aged 35 and over increased from 19 to 22 percent during this time [1]. The social and demographic changes seen in our mothers has led many to ask, “What is the optimum age for childbearing?” The answer to this question is complex, as it is impacted by many social variables as well as medical outcomes. Families, couples, individuals, and their prospective health care providers are likely to have different personal ideologies about family life and the importance of good health. Examining this question from a biosocial view, there is evidence that women who delay childbearing are more likely to have completed a higher level of education, have stable employment and have more wealth. They are less likely to be smokers, more likely to have a healthy diet and are more likely to book early for and attend antenatal care. These factors are all likely to lead to better long-term health outcomes for both the women and their babies. [2, 3] The tradeoff to these social and educational benefits is that with increasing age there are increases in the risk of miscarriage and stillbirth, along with an increase in prevalence of medical conditions which potentially affect pregnancy, such as high blood pressure, diabetes, and kidney disease [3]. There is no single right answer to the question, “What is the optimal age for conception?”; rather, a need to recognize that individuals need to be able to balance their physical, emotional, social, and financial wellbeing. We have limited this review to focus on the medical impact of maternal age in relation to pregnancy

3-D Volume Assessment of the Corpus Callosum and Cerebellar Vermis Using Various Volume Acquisition and Post-Processing Protocols

Objectives: To determine which 3-D techniques are most effective for "real time" prenatal ultrasound assessment of the corpus callosum and cerebellar vermis. Methods: A prospective study involving 100 consecutive normal singleton pregnancies attending routine anomaly scan at 19-23 weeks' gestation. Midsagittal structures of the fetal brain were assessed using six different methods of 3-D image acquisition and three post-processing techniques. The quality of the resulting images were then assessed and scored by a second operator. The significance of the difference between various techniques was assessed using the Friedman test. Results: The best method for visualization of both corpus callosum and cerebellar vermis in one image involved 3-D acquisition in a sagittal plane through the sagittal suture with manipulated 3-D OVIX™ (Oblique View eXtended Imaging) reconstruction. Five other methods scored closely and were not significantly different; all were based on 3-D acquisition in the sagittal plane through either sagittal suture or anterior fontanel. Conclusions: We have applied described techniques for 3-D central nervous system volume acquisition and have shown that the best method of assessment, allowing assessment of both the corpus callosum and the cerebellar vermis, involves midsagittal acquisition through the sagittal suture with 3-D OVIX reconstruction. This technique can be applied successfully in 83% of cases

Intraabdominal masses

Intraabdominal masses are rare and often only recognized in the third trimester of pregnancy. There are typically multiple options for diagnosis, but the differential diagnosis can be narrowed by considering the locality and consistency of the lesion. Magnetic resonance imaging may be useful. Some cases will have other concurrent pathology. Karyotyping may be needed

Quantifying tissue-stiffening behaviour of the cervix in shear-wave elastography

Shear-wave elastography is a useful tool in imaging mechanical properties of soft-tissue. It has great potential to improve the predictive accuracy of preterm birth. This imaging modality, however, has high inter- and intraobserver variability. This is due its sensitivity to changes in pressure and the natural variation in elasticity across the cervix. The aim of this study is to use the artefacts caused by the pressure-dependent increase in shear-wave speed to derive fourth order hyperelastic elasticity tensor of the tissue. The method proposed is as follows: the strain-map of the tissue is extracted by tracking the deformation of the cervix in two raw B-mode images of the ultrasound. Each B-mode image is correlated to a shear-wave map acquired at the same pressure. The relation of the shear-wave speed to the strain is used to derive the parameters of the hyperelastic material model of cervical tissue. A continuous measure of the cervical elasticity parameters is taken. The maps of the parameters are then used to predict the delivery date. In this paper, this method is demonstrated through simulation in FEBio in preparation for a large-scale clinical study at the Royal Prince Alfred Hospital. In the simulation, a tissue of Mooney Rivilin hyperelastic material is indented from 0 mm to 6 mm using a model of the ultrasound probe. The maximum factor increase in shear modulus was 2.63 times which translates to 62 % increase in measured shear-wave speed. The function of the change in shear-wave speed is unique to the parameters of the model

Home blood pressure measurement in women with pregnancy-related hypertensive disorders

Objectives To determine if home blood pressure measurement (HBPM) provides comparable results to clinic blood pressure (BP) measurement. Study design A prospective, single-centre study of 37 pregnant and early post-partum women with a hypertensive pregnancy or at high-risk of developing a hypertensive pregnancy were asked to perform HBPM for a minimum period of one week. This was subsequently compared to clinic BP measurement both before and after the period of home measurement. Main outcome measures The accuracy of HBPM compared to clinic measurement, and the acceptability by patients for HBPM. Results The HBPM was comparable to clinic measurements [for the systolic blood pressure (SBP), the mean home reading was 123.4 mmHg (122.0–124.9 mmHg) versus 123.9 mmHg (121.3–126.5 mmHg) for the clinic reading (p = 0.69); for the diastolic blood pressure (DBP) the mean home reading was 81.6 mmHg (80.4–82.8 mmHg) versus 84.4 mmHg (82.6–86.2 mmHg) for the clinic (p < 0.01)]. There were no reported issues associated with the use of HBPM, but it did lead to 5 women contacting health care professionals for management of their BP between clinic visits. Conclusions HBPM provides comparable results to the clinic BP measurement. It is also an acceptable technique for pregnant and early post-partum women. However, it should be used as an adjunct to clinic measurement, and cannot at this present stage replace clinic visits or clinic BP measurement

Molecular targets of aspirin and prevention of preeclampsia and their potential association with circulating extracellular vesicles during pregnancy

Uncomplicated healthy pregnancy is the outcome of successful fertilization, implantation of embryos, trophoblast development and adequate placentation. Any deviation in these cascades of events may lead to complicated pregnancies such as preeclampsia (PE). The current incidence of PE is 2-8% in all pregnancies worldwide, leading to high maternal as well as perinatal mortality and morbidity rates. A number of randomized controlled clinical trials observed the association between low dose aspirin (LDA) treatment in early gestational age and significant reduction of early onset of PE in high-risk pregnant women. However, a substantial knowledge gap exists in identifying the particular mechanism of action of aspirin on placental function. It is already established that the placental-derived exosomes (PdE) are present in the maternal circulation from 6 weeks of gestation, and exosomes contain bioactive molecules such as proteins, lipids and RNA that are a “fingerprint” of their originating cells. Interestingly, levels of exosomes are higher in PE compared to normal pregnancies, and changes in the level of PdE during the first trimester may be used to classify women at risk for developing PE. The aim of this review is to discuss the mechanisms of action of LDA on placental and maternal physiological systems including the role of PdE in these phenomena. This review article will contribute to the in-depth understanding of LDA-induced PE prevention

Analysis of the integrity of ultrasound probe covers used for transvaginal examinations

Background: Ultrasound probe covers should be used for any ultrasound procedure where there is contact with body fluids or mucous membranes. The type and quality of probe covers used in clinical practice differ widely and studies in the early 1990s showed that condoms were more superior for use with transvaginal examinations than commercial probe covers. Since then, although products have changed, there have been no further studies to assess the breakage rate of different probe covers. The objectives of this study were to assess the integrity of the most commonly used probe covers for transvaginal ultrasound examinations under clinical conditions and report the breakage rate. Methods: The study was conducted in public and private hospitals and private practices. A total of 500 covers for each of 10 brands of commercial covers and condoms (latex and latex free) were distributed to ultrasound practitioners. The transvaginal ultrasound examination practice was unchanged except that all covers were placed in a container for assessment instead of discarding post ultrasound examination. All covers were collected and subjected to a water leak test. Covers that broke upon deployment onto the ultrasound probe prior to the ultrasound examination were recorded. All covers that were broken or had microtears or leaks were recorded as well as photographed. Statistical analysis was performed along with Chi-squared analysis of the data and significance considered at P < 0.05. Results: None of the commercial covers broke upon deployment onto the ultrasound probe prior to ultrasound examination. A total of 5000 probe covers were examined post-transvaginal ultrasound examinations. The breakage rate for condoms ranged from 0.4% to 13% and for commercial covers 0–5%. Statistical analysis of the data by comparison of p-values revealed that the best performing group were the commercial non-latex probe covers and worst performing group were the non-latex condoms. Conclusion: The breakage rates for commercial covers were not as high as previously reported and do not break upon deployment onto the ultrasound probe. This is the first comprehensive study that thoroughly evaluated the integrity of commercial covers and condoms used for transvaginal ultrasound examination in a clinical setting, with regards to brand, numbers and types of covers assessed

Effect of corticosteroids on cardiac function in growth-restricted fetuses

OBJECTIVE: To determine the acute effects of corticosteroids on the cardiovascular system in growth-restricted fetuses.METHODS: This was a prospective cohort study conducted at a tertiary hospital between January 2011 and October 2013. Fetal cardiovascular function in fetuses with intrauterine growth restriction (IUGR) was assessed immediately before and 24 h after the first dose of betamethasone, administered in routine management of IUGR. Fetal arterial and venous Dopplers were assessed. Fetal cardiac function was evaluated by tissue Doppler echocardiography, with the assessment of both left and right ventricular function by calculating myocardial performance index (MPI') and E':A' ratios. Values were compared before and after exposure.RESULTS: Seventeen patients were included at a mean gestational age of 34 + 1 (range, 29 + 1 to 37 + 4) weeks. Fifteen fetuses were below the 5(th) percentile and two were below the 10(th) percentile for estimated fetal weight and abdominal circumference and all had no interval growth during a 2-week period. There was a decrease in right MPI' (from 0.56 to 0.47; P = 0.007) after corticosteroid exposure but no change in left MPI' (from 0.49 to 0.48). Right MPI' was higher than left MPI' before exposure (0.56 vs 0.49, respectively; P = 0.001), but not after exposure (P = 0.55). There was no change in left or right ventricular E':A' ratios and no difference was detected in umbilical artery, middle cerebral artery or ductus venosus pulsatility index following administration of corticosteroids.CONCLUSIONS: Corticosteroids altered right-sided, but not left-sided, tissue Doppler MPI' in IUGR fetuses, with no detectable change in arterial or venous Doppler pulsatility indices. Before exposure, the mean right MPI' was higher than the left. However, after exposure, there was no difference, suggesting that corticosteroids may reverse the negative effect of IUGR on fetal heart function. Large prospective studies with a larger sample size are needed to confirm this finding