Variations on fetal heart rate variability.

This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1113/JP27071

The feasibility and accuracy of ultrasound assessment in the labor room

OBJECTIVE: Vaginal examination is widely used to assess the progress of labor; however, it is subjective and poorly reproducible. We aim to assess the feasibility and accuracy of transabdominal and transperineal ultrasound compared to vaginal examination in the assessment of labor and its progress. METHODS: Women were recruited as they presented for assessment of labor to a tertiary inner city maternity service. Paired vaginal and ultrasound assessments were performed in 192 women at 24-42 weeks. Fetal head position was assessed by transabdominal ultrasound defined in relation to the occiput position transformed to a 12-hour clock face; fetal head station defined as head-perineum distance by transperineal ultrasound; cervical dilatation by anterior to posterior cervical rim measurement and caput succedaneum by skin-skull distance on transperineal ultrasound. RESULTS: Fetal head position was recorded in 99.7% (298/299) of US and 51.5% (154/299) on vaginal examination (p < .0001 1 ). Bland-Altman analysis showed 95% limits of agreement, -5.31 to 4.84 clock hours. Head station was recorded in 96.3% (308/320) on vaginal examination (VE) and 95.9% (307/320) on US (p = .79 1 ). Head station and head perineum distance were negatively correlated (Spearman's r = -.57, p < .0001). 54.4% (178/327) of cervical dilatation measurements were determined using US and 100% on VE/speculum (p < .0001). Bland-Altman analysis showed 95% limits of agreement -2.51-2.16 cm. The presence of caput could be assessed in 98.4% (315/320) of US and was commented in 95.3% (305/320) of VEs, with agreement for the presence of caput of 76% (p < .05). Fetuses with caput greater than 10 mm had significantly lower head station (p < .0001). CONCLUSIONS: We describe comprehensive ultrasound assessments in the labor room that could be translated to the assessment of women in labor. Fetal head position is unreliably determined by vaginal examination and agrees poorly with US. Head perineum distance has a moderate correlation with fetal head station in relation to the ischial spines based on vaginal examination. Cervical dilatation is not reliably assessed by ultrasound except at dilatations of less than 4 cm. Caput is readily quantifiable by ultrasound and its presence is associated with lower fetal head station. Transabdominal and transperineal ultrasound is feasible in the labor room with an accuracy that is generally greater than vaginal examinations

Ultrasound is better tolerated than vaginal examination in and before labour

BACKGROUND: Intrapartum ultrasound has been proposed as a method of assessing labour progress but its acceptability has not been comprehensively assessed. AIMS: We evaluated the acceptability of intrapartum ultrasound in women having vaginal examination (VE) and ultrasound (US) assessment (transabdominal (TA) and transperineal (TP)) prior to delivery, with and without regional analgesia (RA). MATERIALS AND METHODS: Women at 24-42 weeks gestation were included in a prospective observational cohort study. The acceptability of digital VE and TP US were assessed pre- and post-examination using the modified validated Wijma Delivery Experience Questionnaire. Acceptability scores ranged 6-36 (6 being most and 36 being least positive) in six domains: positive-trust and relax, negative-harmful to baby, worrying, painful, intrusive. RESULTS: Of 119 women recruited, 104 completed both pre- and post-assessment questionnaires. Eighty-nine per cent of women were nulliparous with median gestation 40 + 2 weeks (25-42+1 ). Thirty-two per cent had RA before assessment, 91% in total. The combined acceptability scores of both negative and positive experiences (6 = most acceptable, 36 = least acceptable) for VE and US pre-assessment were 15 and 7 respectively (P < 0.0001: Mann-Whitney U-test). VE was associated with less positive / more negative domain scoring post-assessment 12 and 6, respectively (P < 0.0001). Although RA made no difference to the perceived experience pre-VE (P = 0.9), post-VE, women with RAs considered VEs more acceptable than those without RA (P = 0.0022). CONCLUSION(S): This is the first study to comprehensively assess the acceptability of VE and intrapartum US. US assessment prior to delivery is more acceptable than VE. RA ameliorated the negative experience of the VE post-assessment

Change in maternal cardiac output from preconception to mid-pregnancy is associated with birth weight in healthy pregnancies.

OBJECTIVE: Birth weight (BW) is thought to be determined by maternal health and genetic, nutritional and placental factors, the latter being influenced by anatomical development and perfusion. Maternal cardiovascular changes contribute to uteroplacental perfusion; however, they have not yet been investigated in relation to fetal growth or BW. Our aim was to explore the relationship between maternal cardiovascular adaptation, fetal growth and BW in healthy pregnancies. METHODS: This was a longitudinal prospective study of women planning to conceive a pregnancy. Maternal cardiac output (CO), cardiac index (CI), pulse-wave velocity, aortic augmentation index, central blood pressure and peripheral vascular resistance were assessed prior to pregnancy and at 6, 23 and 33 weeks' gestation. Fetal growth was assessed using serial ultrasound measurements of biometry. RESULTS: In total, 143 women volunteered to participate and were eligible for study inclusion. A total of 101 women conceived within 18 months and there were 64 live births with normal pregnancy outcome. There were positive correlations between BW and the pregnancy-induced changes in CO (ρ = 0.4, P = 0.004), CI (ρ = 0.3, P = 0.02) and peripheral vascular resistance (ρ = 0.3, P = 0.02). There were significant associations between second-to-third-trimester fetal weight gain and the prepregnancy-to-second-trimester increase in CO (Δ, 0.8 ± 1.2 L/min; ρ = 0.3, P = 0.02) and CI (Δ, 0.4 ± 0.6 L/min/m2 ; ρ = 0.3, P = 0.04) and reduction in aortic augmentation index (Δ, -10 ± 9%; ρ = -0.3, P = 0.04). CONCLUSIONS: In healthy pregnancy, incremental changes in maternal CO in early pregnancy are associated with third-trimester fetal growth and BW. It is plausible that this association is causative as the changes predate third-trimester fetal growth and eventual BW. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd

Quantitating skill acquisition with optical ultrasound simulation

Objective To investigate and compare the effect of simulator training on quantitative scores for ultrasound‐related skills for trainees with novice level ultrasound experience and expert ultrasound operators. Methods Three novice (comprising of 11, 32, 23 participants) and one expert (10 participants) subgroups undertook an ultrasound simulation training session. Pre‐ and post‐training test scores were collected for each subgroup. Outcome measures were as follows: mean accuracy score for obtaining the correct anatomical plane, percentage of correctly acquired target planes, mean number of movements, time to achieve image, distance travelled by probe and accumulated angling of the probe. Results The novices showed improvement in image acquisition after completion of the simulation training session with an improvement in the rate of correctly acquired target planes from 28–57% to 39–83%. This was not replicated in the experts. The novice’s individual ratios based on pre‐ vs. post‐training metrics improved between 1.7‐ and 4.3‐fold for number of movements, 1.9‐ and 6.7‐fold for distance, 2.0‐ and 5.2‐fold for time taken and 1.8‐ and 7.3‐fold for accumulated angling. Among the experts, there was no relationship between pre‐training simulator metrics and years of ultrasound experience. Conclusions The individual simulation metrics suggest the sessions were delivered at an appropriate level for basic training as novice trainees were able to show demonstrable improvements in both efficiency and accuracy on the simulator. Experts did not improve after the simulation modules, and the novice scores post‐training were similar to those of experts, suggesting the exercises were valid in testing ultrasound skills at novice but not expert level

Change in maternal cardiac output from pre-conception to mid-pregnancy is associated with birth weight in healthy pregnancies

OBJECTIVE: Birth weight (BW) is thought to be determined by maternal health, and genetic, nutritional and placental factors; the latter being influenced by anatomical development and perfusion. Maternal cardiovascular changes contribute to uteroplacental perfusion, however they have not been investigated in relation to fetal growth/BW. Our aim was to explore the relationship between maternal cardiovascular adaptation, fetal growth and BW in healthy pregnancies. METHODS: This was a longitudinal prospective study of women planning to conceive a pregnancy. Maternal cardiac output (CO), cardiac index (CI), pulse-wave velocity, aortic augmentation index (AIx), central blood pressure and peripheral vascular resistance (PVR) were assessed prior to pregnancy and at 6, 23 and 33 weeks' gestation. Fetal growth was assessed by serial ultrasound measurements of biometry. RESULTS: In total, 143 women volunteered to participate and were eligible for study inclusion. One hundred and one women conceived within 18 months and there were 64 live births with normal pregnancy outcome. There were positive correlations between BW and the prepregnancy-to-second trimester changes in CO (ρ = 0.4, P = 0.004), CI (ρ = 0.3, P = 0.02) and PVR (ρ = 0.3, P = 0.02). There were significant associations between third-trimester estimated fetal weight gain and the prepregnancy-to-second trimester increase in CO (Δ, 0.8 ± 1.2 L/min; ρ = 0.3, P = 0.02) and CI (Δ, 0.4 ± 0.6 L/min/m(2) ; ρ = 0.3, P = 0.04) and reduction in AIx (Δ, -10 ± 9%; ρ = -0.3, P = 0.04). CONCLUSIONS: In healthy pregnancy, third-trimester fetal growth and BW are associated with incremental changes in maternal CO in early pregnancy. It is plausible that this association is causative, as changes predate third-trimester fetal growth and eventual BW

ISUOG Practice Guidelines: diagnosis and management of small-for-gestational-age fetus and fetal growth restriction

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Performance of a wearable acoustic system for fetal movement discrimination

Fetal movements (FM) are a key factor in clinical management of high-risk pregnancies such as fetal growth restriction. While maternal perception of reduced FM can trigger self-referral to obstetric services, maternal sensation is highly subjective. Objective, reliable monitoring of fetal movement patterns outside clinical environs is not currently possible. A wearable and non-transmitting system capable of sensing fetal movements over extended periods of time would be extremely valuable, not only for monitoring individual fetal health, but also for establishing normal levels of movement in the population at large. Wearable monitors based on accelerometers have previously been proposed as a means of tracking FM, but such systems have difficulty separating maternal and fetal activity and have not matured to the level of clinical use. We introduce a new wearable system based on a novel combination of accelerometers and bespoke acoustic sensors as well as an advanced signal processing architecture to identify and discriminate between types of fetal movements. We validate the system with concurrent ultrasound tests on a cohort of 44 pregnant women and demonstrate that the garment is capable of both detecting and discriminating the vigorous, whole-body ‘startle’ movements of a fetus. These results demonstrate the promise of multimodal sensing for the development of a low-cost, non-transmitting wearable monitor for fetal movements

Feedlot Factors Influencing the Incidence of Dark Cutting in Australian Grain-Fed Beef

It has been well-established that dark cutting (DC) is a multifactorial issue that is associated with numerous animal and management factors. However, there is limited understanding of the feedlot-based factors that contribute to the influence of DC. The aim of this study was to evaluate the effect of climate, animal, and feedlot factors on the incidence of pH non-compliance in Australian grain-fed cattle. For this study, feedlot and abattoir records from 142,228 individual cattle over a 1-year period were investigated. These data incorporated records from seven feedlots that consigned cattle to three abattoirs. The average incidence of DC in these carcasses was 2.8%. The production factors that were associated with increased risk of DC included feedlot, sex, hormone growth promotants (HGP), cattle health, and days on feed (DOF). Additionally, DC also increased by reduced solar radiation (SR, W/m2), lower wind speeds (WS, m/s), increased ambient temperature (TA, °C), higher rainfall, a higher average temperature–humidity index (THI), and increased duration of time above heat-load-index threshold of 86 (HLI ≥ 86) during the 7 days prior to feedlot departure. This study identified the feedlot factors that increase the risk of DC from a feedlot-management perspective

The stroke oxygen pilot study: a randomized control trial of the effects of routine oxygen supplementation early after acute stroke--effect on key outcomes at six months

Introduction: Post-stroke hypoxia is common, and may adversely affect outcome. We have recently shown that oxygen supplementation may improve early neurological recovery. Here, we report the six-month outcomes of this pilot study. Methods: Patients with a clinical diagnosis of acute stroke were randomized within 24 h of admission to oxygen supplementation at 2 or 3 L/min for 72 h or to control treatment (room air). Outcomes (see below) were assessed by postal questionnaire at 6 months. Analysis was by intention-to-treat, and statistical significance was set at p#0.05. Results: Out of 301 patients randomized two refused/withdrew consent and 289 (148 in the oxygen and 141 in the control group) were included in the analysis: males 44%, 51%; mean (SD) age 73 (12), 71 (12); median (IQR) National Institutes of Health Stroke Scale score 6 (3, 10), 5 (3, 10) for the two groups respectively. At six months 22 (15%) patients in the oxygen group and 20 (14%) in the control group had died; mean survival in both groups was 162 days (p= 0.99). Median (IQR) scores for the primary outcome, the modified Rankin Scale, were 3 (1, 5) and 3 (1, 4) for the oxygen and control groups respectively. The covariate-adjusted odds ratio was 1.04 (95% CI 0.67, 1.60), indicating that the odds of a lower (i.e. better) score were non-significantly higher in the oxygen group (p= 0.86). The mean differences in the ability to perform basic (Barthel Index) and extended activities of daily living (NEADL), and quality of life (EuroQol) were also non-significant. Conclusions: None of the key outcomes differed at 6 months between the groups. Although not statistically significant and generally of small magnitude, the effects were predominantly in favour of the oxygen group; a larger trial, powered to show differences in longer-term functional outcomes, is now on-going. Trial Registration: Controlled-Trials.com ISRCTN12362720; Eudract.ema.europa.eu 2004-001866-4