Placental growth factor in assessment of women with suspected pre-eclampsia to reduce maternal morbidity: a stepped wedge cluster randomised control trial (PARROT Ireland)

OBJECTIVE

To determine whether the addition of placental growth factor (PlGF) measurement to current clinical assessment of women with suspected pre-eclampsia before 37 weeks' gestation would reduce maternal morbidity without increasing neonatal morbidity.

DESIGN

Stepped wedge cluster randomised control trial from 29 June 2017 to 26 April 2019.

SETTING

National multisite trial in seven maternity hospitals throughout the island of Ireland PARTICIPANTS: Women with a singleton pregnancy between 20⁺⁰ to 36⁺⁶ weeks' gestation, with signs or symptoms suggestive of evolving pre-eclampsia. Of the 5718 women screened, 2583 were eligible and 2313 elected to participate.

INTERVENTION

Participants were assigned randomly to either usual care or to usual care plus the addition of point-of-care PlGF testing based on the randomisation status of their maternity hospital at the time point of enrolment.

MAIN OUTCOMES MEASURES

Co-primary outcomes of composite maternal morbidity and composite neonatal morbidity. Analysis was on an individual participant level using mixed-effects Poisson regression adjusted for time effects (with robust standard errors) by intention-to-treat.

RESULTS

Of the 4000 anticipated recruitment target, 2313 eligible participants (57%) were enrolled, of whom 2219 (96%) were included in the primary analysis. Of these, 1202 (54%) participants were assigned to the usual care group, and 1017 (46%) were assigned the intervention of additional point-of-care PlGF testing. The results demonstrate that the integration of point-of-care PlGF testing resulted in no evidence of a difference in maternal morbidity-457/1202 (38%) of women in the control group versus 330/1017 (32%) of women in the intervention group (adjusted risk ratio (RR) 1.01 (95% CI 0.76 to 1.36), P=0.92)-or in neonatal morbidity-527/1202 (43%) of neonates in the control group versus 484/1017 (47%) in the intervention group (adjusted RR 1.03 (0.89 to 1.21), P=0.67).

CONCLUSIONS

This was a pragmatic evaluation of an interventional diagnostic test, conducted nationally across multiple sites. These results do not support the incorporation of PlGF testing into routine clinical investigations for women presenting with suspected preterm pre-eclampsia, but nor do they exclude its potential benefit.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02881073.

O10 Myocardial tolerance to exsanguination and retrieval using whole blood-selective aortic arch perfusion

Introduction

Exsanguination cardiac arrest is the leading preventable cause of death in trauma. Treatment modalities are limited, and prognosis remains dismal. Selective aortic arch perfusion (SAAP) is an emerging endovascular resuscitation technique consisting of aortic occlusion and perfusion of coronary and cerebral circulation with oxygenated resuscitation fluid. Translational research has demonstrated promising outcomes; however, little is known about the duration of cardiac arrest beyond which the myocardium cannot be resuscitated. The aims of this study are to assess the myocardial tolerance to exsanguination cardiac arrest before successful return of spontaneous circulation (ROSC) following resuscitation with SAAP, and 1-hour survival.

Method

23 male adult swine were anaesthetised and instrumented. Controlled hemorrhage was performed until cardiac arrest defined by MAP <20 mmHg. Animals were randomized into 3 groups: 5, 10 and 15 minutes of cardiac arrest before resuscitation with SAAP. Following ROSC animals were observed for 60 minutes.

Result

Baseline characteristics were similar between groups (P > 0.05). ROSC was 100% (8/8) in the 5 min group, 75% (6/8) and 43% (3/7) in 10- and 15-min groups respectively (P = 0.042). 60 min survival was 75%, 50% and 14% in 5-, 10- and 15-min groups respectively (P = 0.015). 1-hour survivors in the 5 min group required less noradrenaline 23.6 (±7.4) compared to other animals 40.9 (±25.8), (P = 0.008).

Conclusion

Selective aortic arch perfusion is an effective resuscitative tool in eliciting ROSC in a swine model of exsanguination cardiac arrest lasting >5 min. Sustainable resuscitability using SAAP declines after 10 min of exsanguination cardiac arrest.

Take-home Message

SAAP is an emerging resuscitation technique with promising outcomes in exsanguination cardiac arrest and may be a segway to Extracorporeal life support. The time limit for resuscitability of the myocardium lies somewhere between 10 and 15 min after the start of exsanguination cardiac arrest.

Sonographic markers of fetal adiposity and risk of Cesarean delivery

OBJECTIVE

Increased fetal size is associated with shoulder dystocia during labor and subsequent need for assisted delivery. We sought to investigate if increased fetal adiposity diagnosed sonographically in late pregnancy is associated with increased risk of operative delivery.

METHODS

This secondary analysis of the Genesis Study recruited 2392 nulliparous women with singleton pregnancy in cephalic presentation, in a prospective, multicenter study, to examine prenatal and intrapartum predictors of Cesarean delivery. Participants underwent ultrasound and clinical evaluation between 39 + 0 and 40 + 6 weeks' gestation. Data on fetal biometry were not revealed to patients or to their managing clinicians. A fetal adiposity composite of fetal thigh adiposity and fetal abdominal wall thickness was compiled for each infant in order to determine whether fetal adiposity > 90^th centile was associated with an increased risk of Cesarean or operative vaginal delivery.

RESULTS

After exclusions, data were available for 2330 patients. Patients with a fetal adiposity composite > 90^th centile had a higher maternal body mass index (BMI) (25 ± 5 kg/m² vs 24 ± 4 kg/m² ; P = 0.005), birth weight (3872 ± 417 g vs 3585 ± 401 g; P < 0.0001) and rate of induction of labor (47% (108/232) vs 40% (834/2098); P = 0.048) than did those with an adiposity composite ≤ 90^th centile. Fetuses with adiposity composite > 90^th centile were more likely to require Cesarean delivery than were those with adiposity composite ≤ 90^th centile (P < 0.0001). After adjusting for birth weight, maternal BMI and need for induction of labor, fetal adiposity > 90^th centile remained a risk factor for Cesarean delivery (P < 0.0001). A fetal adiposity composite > 90^th centile was more predictive of the need for unplanned Cesarean delivery than was an estimated fetal weight > 90^th centile (odds ratio, 2.20 (95% CI, 1.65-2.94; P < 0.001) vs 1.74 (95% CI, 1.29-2.35; P < 0.001). Having an adiposity composite > 90^th centile was not associated with an increased likelihood of operative vaginal delivery when compared with having an adiposity composite ≤ 90^th centile (P = 0.37).

CONCLUSIONS

Fetuses with increased adipose deposition are more likely to require Cesarean delivery than are those without increased adiposity. Consideration should, therefore, be given to adding fetal thigh adiposity and abdominal wall thickness to fetal sonographic assessment in late pregnancy. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

The lipidome of Thoroughbred racehorses before and after supramaximal exercise

BACKGROUND

A comprehensive study of the effect of supramaximal exercise in lipid homeostasis of Thoroughbreds provides the basis for future research on the role of lipids on energy metabolism in racehorses.

OBJECTIVE

To compare the plasma lipidome of Thoroughbreds before and after supramaximal exercise using an untargeted lipidomics approach.

STUDY DESIGN

Pilot experimental study.

METHODS

Four Thoroughbred horses were used. The maximal oxygen consumption (VO_{2 max} ) was calculated for each horse. Horses then underwent treadmill exercise at the speed for which the oxygen requirements had been calculated to be 115% VO_{2 max} . Plasma samples were obtained before (T0) and immediately (T1), 15 (T2) and 30 (T3) minutes post-exercise, and evaluated using liquid chromatography/mass spectrometry. Data analysis consisted of principal component analysis and one-way repeated measures analysis of variance.

RESULTS

A total of 933 plasma lipids were detected. Supramaximal exercise-induced significant changes in the signal intensity of 13 lipids; all ubiquitous in the organism as major components of biological membranes or energy substrates.

MAIN LIMITATIONS

A treadmill was used to replicate track conditions. Also, sample size involved only four horses and the statistical analyses failed to achieve the desired power of 80%.

CONCLUSIONS

The findings in this pilot study suggest that supramaximal exercise induces changes in specific plasma lipids in Thoroughbred racehorses. While the biological significance of these findings remains to be determined, these results provide baseline information for future studies in lipidomics applied to equine exercise physiology. Further research is warranted to better understand the role of lipids on energy metabolism in Thoroughbred racehorses.

Admission cardiotocography versus intermittent auscultation of the fetal heart in low-risk pregnancy during evaluation for possible labour admission - a multicentre randomised trial: the ADCAR trial

OBJECTIVE

To assess the effect of admission cardiotocography (ACTG) versus intermittent auscultation (IA) of the fetal heart (FH) in low-risk pregnancy during assessment for possible labour on caesarean section rates.

DESIGN

A parallel multicentre randomised trial.

SETTING

Three maternity units in the Republic of Ireland.

POPULATION

Healthy, low-risk pregnant women, at term and ≥ 18 years old, who provided written informed consent.

METHODS

Women were randomised to receive IA of the FH or 20 minutes ACTG on admission for possible labour onset, using remote telephone randomisation. Both groups received IA during labour, with conversion to continuous CTG as clinically indicated.

MAIN OUTCOME MEASURES

Caesarean section (primary outcome), obstetric interventions (e.g. continuous CTG during labour, fetal blood sampling, augmentation of labour) and neonatal morbidity (e.g. metabolic acidosis, admission to the neonatal intensive care unit, neonatal death).

RESULTS

Based on 3034 women (1513 and 1521 randomised to IA and ACTG, respectively), there was no statistical difference between the groups in caesarean section [130 (8.6%) and 105 (6.9%) for IA and ACTG groups, respectively; relative risk (RR) 1.24; 95% CI 0.97-1.58], or in any other outcome except for use of continuous CTG during labour, which was lower in the IA group (RR 0.90, 95% CI 0.86-0.93).

CONCLUSION

Our study demonstrates no differences in obstetric or neonatal outcomes between IA and ACTG for women with possible labour onset, other than an increased risk for continuous CTG in women receiving ACTG.

TWEETABLE ABSTRACT

No differences in outcomes between intermittent auscultation and admission cardiotocography for women with possible labour onset.

The use of aortic balloon occlusion in traumatic shock: first report from the ABO trauma registry

PURPOSE

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a technique for temporary stabilization of patients with non-compressible torso hemorrhage. This technique has been increasingly used worldwide during the past decade. Despite the good outcomes of translational studies, clinical studies are divided. The aim of this multicenter-international study was to capture REBOA-specific data and outcomes.

METHODS

REBOA practicing centers were invited to join this online register, which was established in September 2014. REBOA cases were reported, both retrospective and prospective. Demographics, injury patterns, hemodynamic variables, REBOA-specific data, complications and 30-days mortality were reported.

RESULTS

Ninety-six cases from 6 different countries were reported between 2011 and 2016. Mean age was 52 ± 22 years and 88% of the cases were blunt trauma with a median injury severity score (ISS) of 41 (IQR 29-50). In the majority of the cases, Zone I REBOA was used. Median systolic blood pressure before balloon inflation was 60 mmHg (IQR 40-80), which increased to 100 mmHg (IQR 80-128) after inflation. Continuous occlusion was applied in 52% of the patients, and 48% received non-continuous occlusion. Occlusion time longer than 60 min was reported as 38 and 14% in the non-continuous and continuous groups, respectively. Complications, such as extremity compartment syndrome (n = 3), were only noted in the continuous occlusion group. The 30-day mortality for non-continuous REBOA was 48%, and 64% for continuous occlusion.

CONCLUSIONS

This observational multicenter study presents results regarding continuous and non-continuous REBOA with favorable outcomes. However, further prospective studies are needed to be able to draw conclusions on morbidity and mortality.

A systematic review and meta-analysis of the use of resuscitative endovascular balloon occlusion of the aorta in the management of major exsanguination

BACKGROUND

Circulatory collapse is a leading cause of mortality among traumatic major exsanguination and in ruptured aortic aneurysm patients. Approximately 40% of patients die before hemorrhage control is achieved. Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an adjunct designed to sustain the circulation until definitive surgical or endovascular repair. A systematic review was conducted for the current clinical use of REBOA in patients with hemodynamic instability and to discuss its potential role in improving prehospital and in-hospital outcome.

METHODS

Systematic review and meta-analysis (1900-2017) using MEDLINE, Cochrane, EMBASE, Web of Science and Central and Emcare using the keywords "aortic balloon occlusion", "aortic balloon tamponade", "REBOA", and "Resuscitative Endovascular Balloon Occlusion" in combination with hemorrhage control, hemorrhage, resuscitation, shock, ruptured abdominal or thoracic aorta, endovascular repair, and open repair. Original published studies on human subjects were considered.

RESULTS

A total of 490 studies were identified; 89 met criteria for inclusion. Of the 1436 patients, overall reported mortality was 49.2% (613/1246) with significant differences (p < 0.001) between clinical indications. Hemodynamic shock was evident in 79.3%, values between clinical indications showed significant difference (p < 0.001). REBOA was favored as treatment in trauma patients in terms of mortality. Pooled analysis demonstrated an increase in mean systolic pressure by almost 50 mmHg following REBOA use.

CONCLUSION

REBOA has been used in trauma patients and ruptured aortic aneurysm patients with improvement of hemodynamic parameters and outcomes for several decades. Formal, prospective study is warranted to clarify the role of this adjunct in all hemodynamic unstable patients.

3 Safely landing a resuscitative endovascular balloon occlusion of the aorta (REBOA) device in zone one

Background

Non-compressible torso haemorrhage is a leading cause of potentially preventable death following trauma. Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) is a technique to temporise haemorrhage. Areas for potential inflation have been characterised as zones I – III. Placement superior to zone I may cause harm. Fluoroscopy, used to confirm position, is often unavailable. The literature shows disagreement about whether a fixed insertion distance would be safe. Some papers advocate using a multi-variable insertion formula.

Methods

Three cohorts of patients underwent retrospective analysis of their aortic morphometry. The patients had undergone CT imaging of their torsos when they presented to one of three centres following serious traumatic injury. Aortic reconstructions were performed and measurements taken. Virtual balloons were inserted to both fixed distances and distances calculated using previously reported formulae.

Results

The study population consisted of trauma patients presenting to Camp Bastion, Afghanistan [n=177]; St Mary’s Hospital, London, UK [n=100]; Wilford Hall Hospital, Texas, US [n=88]. When compared, the 3 cohorts were sufficiently similar for combined analysis (n=365). The two fixed insertion distances (444 mm and 418 mm) each conveyed virtual balloon placement accuracies of 98.4% (359/365). The placements proximal to Zone I occurred in those patients with the smallest 2% of torso heights. The 2 formulae for calculating zone I insertion length each conveyed accuracy of 99.7% (364/365). Statistical analysis found no significant difference between formulaic and fixed insertion distance accuracies (p=0.07).

Conclusion

Fixed distance insertion is more practical in an emergency situation; formulae conveyed no greater accuracy. Fixed distances may not suit a minority of patients who are in the extreme of a population’s height range. These findings support the trial of a zone I fixed distance insertion algorithm.

Maternal body mass index and spontaneous contractility of human myometrium in pregnancy

OBJECTIVE

There is controversy as to whether maternal body mass index (BMI) influences the contractility of human myometrium in pregnancy. The aim of this study was to examine spontaneous contractile activity of human pregnant myometrium in vitro, with respect to maternal BMI.

STUDY DESIGN

Myometrial tissue specimens were obtained at cesarean delivery from 74 women with BMI values ranging from 19 to 50.1 kg m^-2. By recording in vitro from eight strips per donor (590 strips in total), several parameters of spontaneous contractile activity were monitored. The relationship between BMI and contractility was evaluated using linear regression analysis.

RESULTS

There was a significant correlation between maximum amplitude (P=0.007) and mean contractile force (P=0.001) with increasing BMI. However, the time to onset of contractions (P=0.009), and time taken to reach maximal amplitude (P=0.020) also increased with increasing BMI. No significant correlation was observed with BMI for other parameters studied. The mean maximum amplitude value for spontaneous contractions was 37±1 mN, the mean contractile force for spontaneous contractions was 4.1±0.1 mN, the average time to the first spontaneous contraction was 11.3±0.6 min and the average frequency of contractions was 6.5±0.2 per hour.

CONCLUSIONS

These results suggest that the time to onset of contractions is increased with increasing maternal BMI, but that the force developed is greater. In all other respects, human uterine contractility is unaffected by increasing BMI. These findings underline the complexity of regulation of uterine contractility in labor with elevated maternal BMI.

Resuscitative endovascular balloon occlusion of the aorta: what is the optimum occlusion time in an ovine model of hemorrhagic shock?

PURPOSE

The aim of this study is to evaluate the early survival and organ damage following 30 and 60 min of thoracic resuscitative endovascular balloon occlusion of the aorta (REBOA) in an ovine model of severe hemorrhagic shock.

METHODS

Eighteen sheep were induced into shock by undergoing a 35 % controlled exsanguination over 30 min. Animals were randomized into three groups: 60-min REBOA 30 min after the bleeding (60-REBOA), 30-min REBOA 60 min after the bleeding (30-REBOA) and no-REBOA control (n-REBOA). Resuscitation with crystalloids and whole blood was initiated 20 and 80 min after the induction of shock. Animals were observed for 24 h with serial potassium and lactate measurements. Autopsy was performed to evaluate organ damage.

RESULTS

Two animals of the n-REBOA group died within 90 min of shock induction; no hemorrhagic deaths were observed in the REBOA groups. Twenty-four-hour survival for the 60-, 30-, and n-REBOA groups was 0/6, 5/6, and 4/6 (P = 0.002). In 60-REBOA, potassium and lactate were increased at 270-min time point: from 4.3 to 5.1 mEq/l and from 3.7 to 5.1 mmol/L, respectively. Both these values were significantly higher than in the n-REBOA group (P = 0.029 for potassium and P = 0.039 for lactate). Autopsy revealed acute tubular necrosis in all died REBOA group animals.

CONCLUSIONS

In this ovine model of severe hemorrhagic shock, REBOA can be used to prevent early death from hemorrhage; however, 60 min of occlusion results in significant metabolic derangement and organ damage that offsets this gain.

An orthogonal C–H borylation – cross-coupling strategy for the preparation of tetrasubstituted “A2B2”-chrysene derivatives with tuneable photophysical properties

Cl-substituents serve as a functionalisable regiocontrol element for the orthogonal functionalisation of chrysene.

Changes in blood transfusion practices in the UK role 3 medical treatment facility in Afghanistan, 2008-2011

OBJECTIVE

To document blood component usage in the UK medical treatment facility, Afghanistan, over a period of 4 years; and to examine the relationship with transfusion capability, injury pattern and survival.

BACKGROUND

Haemostatic resuscitation is now firmly established in military medical practice, despite the challenges of providing such therapy in austere settings.

MATERIALS AND METHODS

Retrospective study of blood component use in service personnel admitted for trauma. Data were extracted from the UK Joint Theatre Trauma Registry.

RESULTS

A total of 2618 patients were identified. Survival increased from 76 to 84% despite no change in injury severity. The proportion of patients receiving blood components increased from 13 to 32% per annum; 417 casualties received massive transfusion (≥10 units of RCC), the proportion increasing from 40 to 62%. Use of all blood components increased significantly in severely injured casualties, to a median (IQR) of 16 (9-25) units of red cell concentrate (P = 0·006), 15 (8-24) of plasma (P = 0·002), 2 (0-5) of platelets (P < 0·001) and 1 (0-3) of cryoprecipitate (P < 0·001). Cryoprecipitate (P = 0·009) and platelet use (P = 0·005) also increased in moderately injured casualties.

CONCLUSIONS

The number of blood components transfused to individual combat casualties increased during the 4-year period, despite no change in injury severity or injury pattern. Survival also increased. Combat casualties requiring massive transfusion have a significantly higher chance of survival than civilian patients. Survival is the product of the entire system of care. However, we propose that the changes in military transfusion practice and capability have contributed to increased combat trauma survival.

The UK military experience of thoracic injury in the wars in Iraq and Afghanistan

INTRODUCTION

Thoracic injury during warfare is associated with a high incidence of morbidity and mortality. This study examines the pattern and mortality of thoracic wounding in the counter-insurgency conflicts of Iraq and Afghanistan, and outlines the operative and decision making skills required by the modern military surgeon in the deployed hospital setting to manage these injuries.

METHODS

The UK Joint Theatre Trauma Registry was searched between 2003 and 2011 to identify all patients who sustained battle-related thoracic injuries admitted to a UK Field Hospital (Role 3). All UK soldiers, coalition forces and local civilians were included.

RESULTS

During the study period 7856 patients were admitted because of trauma, 826 (10.5%) of whom had thoracic injury. Thoracic injury-related mortality was 118/826 (14.3%). There were no differences in gender, age, coalition status and mechanism of injury between survivors and non-survivors. Survivors had a significantly higher GCS, Revised Trauma Score and systolic blood pressure on admission to a Role 3 facility. Multivariable regression analysis identified admission systolic blood pressure less than 90, severe head or abdominal injury and cardiac arrest as independent predictors of mortality.

CONCLUSIONS

Blast is the main mechanism of thoracic wounding in the recent conflicts in Iraq and Afghanistan. Thoracic trauma in association with severe head or abdominal injuries are predictors of mortality, rather than thoracic injury alone. Deploying surgeons require training in thoracic surgery in order to be able to manage patients appropriately at Role 3.

Intra-operative correction of acidosis, coagulopathy and hypothermia in combat casualties with severe haemorrhagic shock

We assessed acidosis, coagulopathy and hypothermia, before and after surgery in 51 combat troops operated on for severe blast injury. Patients were transfused a median (IQR [range]) of 27 (17-38 [5-84]) units of red cell concentrate, 27 (16-38 [4-83]) units of plasma, 2.0 (0.5-3.5 [0-13.0]) units of cryoprecipitate and 4 (2-6 [0-17]) pools of platelets. The pH, base excess, prothrombin time and temperature increased: from 7.19 (7.10-7.29 [6.50-7.49]) to 7.45 (7.40-7.51 [7.15-7.62]); from -9.0 (-13.5 to -4.5 [-28 to -2]) mmol.l⁻¹ to 4.5 (1.0-8.0 [-7 to +11]) mmol.l⁻¹; from 18 (15-21 [9-24]) s to 14 (11-18 [9-21]) s; and from 36.1 (35.1-37.1 [33.0-38.1]) °C to 37.4 (37.0-37.9 [36.0-38.0]) °C, respectively. Contemporary intra-operative resuscitation strategies can normalise the physiological derangements caused by haemorrhagic shock.

Rural and urban distribution of trauma incidents in Scotland

Background

Trauma systems reduce mortality and improve functional outcomes from injury. Regional trauma networks have been established in several European regions to address longstanding deficiencies in trauma care. A perception of the geography and population distribution as challenging has delayed the introduction of a trauma system in Scotland. The characteristics of trauma incidents attended by the Scottish Ambulance Service were analysed, to gain a better understanding of the geospatial characteristics of trauma in Scotland.

Methods

Data on trauma incidents collected by the Scottish Ambulance Service between November 2008 and October 2010 were obtained. Incident location was analysed by health board region, rurality and social deprivation. The results are presented as number of patients, average annual incidence rates and relative risks.

Results

Of the 141 668 incidents identified, 72·1 per cent occurred in urban regions. The risk of being involved in an incident was similar across the most populous regions, and decreased slightly with increasing rurality. Social deprivation was associated with greater numbers and risk. A total of 53·1 per cent of patients were taken to a large general hospital, and 38·6 per cent to a teaching hospital; the distribution was similar for the subset of incidents involving patients with physiological derangements.

Conclusion

The majority of trauma incidents in Scotland occur in urban and deprived areas. A regionalized system of trauma care appears plausible, although the precise configuration of such a system requires further study.

Moderate and extreme maternal obesity

The aim of this study was to investigate the prevalence of moderate and extreme obesity among an Irish obstetric population over a 10-year period, and to evaluate the obstetric features of such pregnancies. Of 31,869 women delivered during the years 2000-2009, there were 306 women in the study group, including 173 in the moderate or Class 2 obese category (BMI 35-39.9) and 133 in the extreme or Class 3 obese category (BMI > or = 40).The prevalence of obese women with BMI > or = 35 was 9.6 per 1000 (0.96%), with an upward trend observed from 2.1 per 1000 in the year 2000, to 11.8 per 1000 in the year 2009 (P = 0.001). There was an increase in emergency caesarean section (EMCS) risk for primigravida versus multigravid women, within both obese categories (P < 0.001). However, there was no significant difference in EMCS rates observed between Class 2 and Class 3 obese women, when matched for parity. The prevalence of moderate and extreme obesity reported in this population is high, and appears to be increasing. The increased rates of abdominal delivery, and the levels of associated morbidity observed, have serious implications for such women embarking on pregnancy.

Associated injuries in casualties with traumatic lower extremity amputations caused by improvised explosive devices

BACKGROUND

Improvised explosive devices (IEDs) pose a significant threat to military personnel, often resulting in lower extremity amputation and pelvic injury. Immediate management is haemorrhage control and debridement, which can involve lengthy surgery. Computed tomography is necessary to delineate the extent of the injury, but it is unclear whether to perform this during or after surgery.

METHODS

The UK Joint Theatre Trauma Registry was searched to identify all UK service personnel who had a traumatic lower extremity amputation following IED injury between January 2007 and December 2010. Data were collected on injury pattern and survival.

RESULTS

There were 169 patients who sustained 278 traumatic lower extremity amputations: 69 were killed in action, 16 died from their wounds and 84 were wounded in action, but survived. The median (interquartile range) Injury Severity Score was 75 (21) for those killed in action, 46 (23) for those who died from wounds and 29 (12) for survivors. There were significantly more severe head, chest and abdominal injuries (defined as a body region Abbreviated Injury Scale score of 3 or more) in patients who were killed in action than in those reaching hospital (P < 0·001). Hindquarter amputations were the most lethal, with a mortality rate of 95 per cent. Of the 100 casualties who reached hospital alive, there were nine thoracotomies, one craniotomy and 34 laparotomies. All head or torso injuries that required immediate operation were clinically apparent on admission.

CONCLUSION

Higher levels of amputation were associated with greater injury burden and mortality. Intraoperative computed tomography had little value in identifying clinically significant covert injuries.

Ballistic thoracoabdominal injury: analysis of recent military experience in afghanistan

BACKGROUND

Military surgery has seen the arrival of the critical care provision and cross-sectional imaging enjoyed by civilian trauma surgeons. Ballistic injury to the thoracoabdominal region is uncommon but potentially devastating. The aim of this study was to analyze recent military experience of managing this injury complex.

METHODS

The study is a retrospective analysis of patients, admitted over a 12-month period, to the British Military Hospital in Afghanistan with ballistic thoracoabdominal injuries.

RESULTS

In total, 27 patients sustained combined thoracoabdominal injury with a mean new injury severity score of 29±12, revised trauma score of 5.94±2.93 and predicted survival of 71.1%±39.1%. In all, 20 (74%) patients underwent immediate operation, and 7 (26%) were initially managed nonoperatively. Of those requiring surgery, 11 required laparotomy and tube thoracostomy, and 9 required thoraco-laparotomy. Of the seven casualties who were initially observed and/or further investigated, two required laparotomy following computed tomography scanning, and five were managed conservatively, two of whom required delayed surgery. There were nine fatalities, all within 16 days of being wounded. Four patients died from exsanguination, one from a traumatic brain injury, and four from multiorgan failure. Five patients presented with cardiac arrest, two of whom survived.

CONCLUSIONS

Exploration remains the default treatment. Resuscitative thoracotomy may yield unexpected survivors, even if subsequent laparotomy is required. Nonoperative management appears to be feasible in a small proportion of patients but requires careful selection supported by cross-sectional imaging.

Is pre-hospital thoracotomy necessary in the military environment?

INTRODUCTION

Exsanguination from penetrating torso injury is a major source of mortality on the battlefield. Advanced Life Support guidelines suggest 'on-scene' thoracotomy for patients in cardiac arrest following penetrating chest trauma. This requires significant resourcing and training. Experience from published series (31 pre-hospital thoracotomies with 3 survivors) suggests that when this manoeuvre is applied to a well selected group it is a significant and life-saving procedure. Can this be applied to military injuries?

METHODS

Over a 12 month period on Operation Herrick all patients who sustained significant thoracic trauma were retrospectively reviewed. Parameters were recorded to allow detailed analysis of injury pattern and operative management. Our main objective was to determine if an early (pre-hospital) thoracotomy would have influenced the outcome.

RESULTS

Over the period, 81 patients required operative intervention following thoracic trauma: 8 patients underwent emergency thoracotomy (performed as part of the resuscitation) and 14 underwent urgent thoracotomy (performed after physiology partly restored). There were 9 fatalities--7 undergoing emergency thoracotomy and 2 post-operatively from multi-organ failure. Of the 7 intra-operative deaths 4/7 patients had thoracic injury and 6/7 had additional abdominal injuries. The median predicted survival of fatalities was 2.0% using Trauma Injury Severity Scoring.

DISCUSSION

Emergency thoracotomy should be performed in cardiac arrest following penetrating trauma as soon as possible. Highest survival rates in both in-hospital and pre-hospital thoracotomy are found in isolated cardiac stab wounds (19.4%). Poorest survival is found in multiply, ballistic injured patients (0.7%). The latter best reflects the injury pattern of military patients who have cardiac arrest following penetrating torso injury.

CONCLUSION

As our injury pattern suggests, any pre-hospital thoracotomy on military patients is likely to require complex intervention in very challenging environments. Our evidence does not support the notion that earlier thoracotomy could improve survival.

Trends in the obstetric features and management of twin pregnancies

There are no reports outlining the trends in obstetric features and clinical management of twin pregnancies in an Irish obstetric population. The aim of this study was to investigate these factors for all twin pregnancies delivered during the 19 year period between 1989 and 2007, at Galway University Hospital (GUH). There were 52,199 infants delivered at GUH, of which 1594 infants (3.05% of births) were twins, related to 797 twin pregnancies. The overall incidence of twin pregnancies was 1.52%, increasing from 0.8%-1.0% in the early years of the study to 1.7-1.8% in the latter years of the study (P<0.001). There was a significant increase in incidence of twins born to mothers aged 30-39 years, alongside a significant reduction to mothers aged 20-29 years (P<0.01). The caesarean section rate overall was 41.5% (331/797), of which 54% (n=179) were elective, and 46% (n=152) were emergency, representing an emergency caesarean section rate of 19.1% of all twin pregnancies, and of 24.6% after exclusion of elective caesarean sections. The caesarean section rate for twins increased from 30% in 1989 to greater than 50% in the latter years of the study (P<0.01), related largely to a significant increase in elective caesarean sections (P<0.01). The combined vaginal-caesarean delivery rate was remarkably low at 0.75% of all twin pregnancies, and 1% after exclusion of elective caesarean sections. The preterm delivery rates were 4.1% (<32 weeks), and 16.3% (<36 weeks), with an overall perinatal mortality rate of 37 per 1000. These findings highlight the altered demographic and clinical aspects of twin pregnancies in an Irish obstetric population.

SAR150640, a selective beta3-adrenoceptor agonist, prevents human myometrial remodelling and activation of matrix metalloproteinase in an in vitro model of chorioamnionitis

BACKGROUND AND PURPOSE

The uterine pathophysiology underlying inflammatory conditions such as chorioamnionitis remains largely unclear. As we have shown that beta(3)-adrenoceptors act as regulators of myometrial inflammation, we wanted to investigate the potential role of beta(3)-adrenoceptors in preventing uterine remodelling induced by inflammation.

EXPERIMENTAL APPROACH

The consequences of human chorioamnionitis on myometrial remodelling were characterized by Sirius Red staining and metalloproteinase (MMP) expression, and compared with the effects of incubating human myometrial samples with Escherichia coli lipopolysaccharide (LPS) in vitro. We also assessed the effect of SAR150640, a selective beta(3)-adrenoceptor agonist, on the production and activity of MMPs.

KEY RESULTS

Chorioamnionitis was associated with a 46% decrease in total collagen, as well as over-expression of MMP2 (+61%) and MMP9 (+84%); both effects were reproduced by incubation with LPS (10 microg x mL(-1), 48 h). LPS-induced over-expression of MMP2 and MMP9 in normal human myometrium was paralleled by an overactivity of the proteins. Both over-expression and overactivity were prevented by the beta(3)-adrenoceptor agonist SAR150640 in a concentration-dependent manner. SAR150640, by itself, did not exhibit any effect on MMP production in control tissues.

CONCLUSIONS AND IMPLICATIONS

This study shows that inflammation was associated with an intense remodelling of human myometrium, a process likely to be explained by MMP activation. Our study emphasizes the potential therapeutic relevance of beta(3)-adrenoceptor agonists to the treatment of preterm labour and other uterine inflammatory conditions.

Occupational predictors of pregnancy outcomes in Irish working women in the Lifeways cohort

OBJECTIVE

The objective of this study was to explore the association between occupational factors and pregnancy outcomes in a prospective cohort of Irish pregnant women.

DESIGN

This study has a prospective design.

POPULATION

The Lifeways cohort included 1124 pregnant women, 676 of whom delivered a single baby and were working at their first prenatal care visit when they filled in a self-administered questionnaire.

METHODS

Occupational factors were measured using this questionnaire and included eight factors describing job and working conditions. Data including pregnancy outcomes were also obtained from clinical hospital records. Logistic regression analysis was used to adjust for well-known risk factors.

MAIN OUTCOME MEASURES

Birthweight (< or =3000 g and < or =2500 g), preterm delivery (<37 gestation weeks) and small-for-gestational-age.

RESULTS

Significant associations were found between physical work demands and low birthweight (< or =2500 g) and working with between a temporary contract and preterm delivery. Trends were also observed between working 40 hours or more a week and shift work, and birthweight of 3000 g or less. The study of a cumulative index showed that being exposed to at least two of these occupational factors significantly predicted birthweight of < or =3000 g (OR = 2.44, 95% CI: 1.17-5.08) and of < or =2500 g (OR = 4.65, 95% CI: 1.08-20.07) and preterm delivery (OR = 5.18, 95% CI: 1.00-27.01).

CONCLUSIONS

Our findings suggest that occupational factors may predict birthweight through their predictive effects on preterm delivery. This is one of the few prospective studies on pregnancy outcomes that include working conditions. As they may be modifiable, occupational factors deserve more attention in relation to birth outcomes.

Dietary habits of pregnant women in Ireland

This analysis of the Lifeways Cohort study mothers during pregnancy (n = 1124), utilises information from a standard food frequency questionnaire completed at baseline recruitment during early pregnancy. We demonstrate that 76% of women achieved recommended intakes of 5 plus portions of fruit and vegetables daily, though this is strongly socially patterned, inversely associated with age and positively associated with level of education. Achievement of the other recommended shelf intakes of the Food Pyramid is much lower, ranging from 12% achieving the recommended sparing intake of foods high in fat, salt or sugar, to 45% consuming the recommended 3 portions per day of meat and poultry. General medical services eligible respondents are generally less likely to achieve recommended intakes. While 61% of women under 25 years old stopped drinking during pregnancy, this dropped to 38% of expectant mothers over 35 years. Less than half (45%) of those (n = 860) who responded specifically to the question reported peri-conceptual folate supplement intake, again strongly socially patterned. These findings both provide important prevalence data and highlight the need for more concerted and supportive health promotion interventions during pregnancy.

Self-reported pre-pregnancy maternal body mass index and infant birth-weight

This analysis examines the association between maternal characteristics, particularly body mass index (BMI) and infant birth weight in 1048 live infants. Mean reported pre pregnancy BMI of mothers was 23.74 kg/m2 (SD 4.21). The educational level of the mother's parents was independently associated with maternal BMI, those with higher educated parents having a lower reported BMI (F = 2.787, p = 0.029). Mean infant birth weight was 3493 g (SD 18.1) and there was a strong graduated relationship to estimated gestational age. In a sub-group of participating maternal grandmothers (n = 171), reported BMI was 26.7Kg/m2. The BMI of expectant mothers was significantly associated with their own mother's BMI. (r = 0.179, p = 0.005) in this sub-group. These preliminary findings, which will be investigated further with recorded height and weight information, suggest that familial factors are influential, perhaps through genetic predisposition or shared socio-cultural factors such as diet.

Socio-demographic, lifestyle and cross-generation predictors of self-rated health in mothers during pregnancy

The Lifeways Cross-generation study was established to assess the influence of socio-economic and familial characteristics on the health status and early development of children. Between October 2001 and June 2002, 1124 women were recruited to the Lifeways study at booking or first visit to maternity hospital. Lifeways mothers were 29.4 (SD 5.9) years old at recruitment, two-thirds from greater Dublin area, 17.9% held a General Medical Services (GMS) card, 64.3% were married and 40.8% were third level educated. At uni-variate level, GMS eligibility, own and parents' education and marital status all predicted mother's self rated health during pregnancy, whilst in the final multivariate logistic regression model, GMS status, household-adjusted income, marital status and grand-maternal education were each independently predictors. The Lifeways cohort confirms the importance of social position in predicting health in pregnant Irish women.

Medium-Fidelity Medical Simulators: Use in a Pre-Hospital,Operational, Military Environment

On Operation Telic 6, the UK Med Group consisting of 3 Close Support Medical Regiment and 205 Field Hospital (Volunteers) deployed to provide medical support to coalition forces in Iraq. Personnel were drawn from Regular and Territorial Units, plus additional medical support from Armies of the Czech Republic and Denmark. The efficient delivery of operational emergency medical care hinged upon the successful integration of personnel from these units. We report on the use of a medium-fidelity simulator, in a pre-hospital and hospital environment over a three month period on an operational tour. In conducting 42 exercises (12 of which commenced in a pre-hospital environment), we have demonstrated the feasibility of the system in rehearsing the management of the major trauma patient. This training was used to enhance teamwork, identify system deficiencies and practise solutions in a safe environment. This paper discusses our experiences in relation to the current literature on this expanding area of trauma training.

Fetal cortisol in relation to labour, intrapartum events and mode of delivery

We set out to measure fetal cortisol in the human umbilical vein in relation to onset of labour, intrapartum complications and mode of delivery. Umbilical cord venous samples were obtained after delivery from 98 infants and serum total cortisol was measured. The onset of spontaneous labour, induction of labour, elective caesarean section, spontaneous vaginal delivery, emergency caesarean section in labour, instrumental delivery, the presence of meconium staining of the liquor and umbilical artery pH were examined in relation to serum fetal cortisol. Spontaneous onset of labour, mode of delivery, meconium staining of the liquor and gestational age were independent predictors of umbilical venous cortisol levels. Those infants delivered by elective caesarean section had the lowest cortisol levels, while the highest levels were recorded in those infants following instrumental delivery. Fetal cortisol is significantly elevated in association with spontaneous human parturition and is highest Its among babies born by instrumental delivery.

Effects of thyrotropin-releasing hormone on human myometrium and umbilical vasculature in vitro

OBJECTIVE

The purpose of this study was to investigate the direct effects of thyrotropin-releasing hormone on isolated human myometrium that was obtained during pregnancy and on human umbilical vasculature in vitro.

STUDY DESIGN

Isolated human myometrial strips were dissected from biopsy specimens that were obtained at elective cesarean delivery and suspended for isometric recording under physiologic conditions. The effects of cumulative additions of thyrotropin-releasing hormone (10(-9)-10(-4) mol/L) on oxytocin-induced myometrial contractility were evaluated. The effects of thyrotropin-releasing hormone (10(-9)-10(-4) mol/L) on umbilical vessel (artery and vein) resistance in vitro were investigated with the use of isolated ring preparations.

RESULTS

Thyrotropin-releasing hormone exerted a significant concentration-dependent relaxant effect on pregnant human myometrial tissue, which ranged from 3.54% (10(-9) mol/L, P=.935) to a net cumulative total of 21.06% (10(-4) mol/L, P<.001). Thyrotropin-releasing hormone also exerted a concentration-dependent relaxant effect on human umbilical vasculature that ranged from 12.51% (10(-9) mol/L, P=.994) to a net cumulative total of 23.27%+/-4.87% (SEM, 10(-4) mol/L, P<.01) in umbilical artery. For umbilical vein, the relaxant effect ranged from 1.80% (10(-9) mol/L, P=.998) to a net cumulative total of 14.64% (10(-4) mol/L, P<.009).

CONCLUSION

Thyrotropin-releasing hormone exerts a significant relaxant effect in human myometrium and in human umbilical vasculature and highlights a potential physiologic role for this neuropeptide in these tissues. These findings have clinical implications for the therapeutic use of thyrotropin-releasing hormone antenatally.

Attitudes towards routine prenatal diagnostic investigations in obstetric practice in the Republic of Ireland

The aim of this study was to evaluate the attitudes of pregnant women towards prenatal diagnosis in the Republic of Ireland. A questionnaire was administered to all women attending the antenatal clinic at University College Hospital, Galway between January and May 1999. 1042 women participated in the study and 1012 (97%) questionnaires were completed correctly. The majority of women, 763 (75.4%) and 748 (73.9%) respectively, would avail of a fetal anomaly scan or biochemical screening if available. However, confusion exists about the purpose of ultrasound scans currently available. The majority of respondents (71%) thought that the purpose of the currently available scan was to detect fetal abnormality. In reality, the primary purpose of the scan currently available is for other purposes and the detection of fetal abnormality is performed opportunistically rather than systematically. This confusion may reflect poor provision of information to our antenatal patients and should be addressed within by the obstetric service.

Surgically relevant structure on the ascending aorta

We have examined the transverse vascularized ridge observed on the anterior surface of the intra-pericardial aorta during cardiac surgery. The ridge was a consistent feature of 20 consecutive cardiac patients and 11 cadavers no more than 2 days post-mortem. The aortic ridge was absent, however, in four of five embalmed cadavers additionally examined, probably due to the embalming process. Histological examination showed the ridge to be well vascularized, well innervated and composed of adipose tissue. This structure has surgical relevance as a possible source of post-operative hemorrhage, sometimes necessitating re-sternotomy.

Ultrasound detection and perinatal outcome of fetal trisomies 21, 18 and 13 in the absence of a routine fetal anomaly scan or biochemical screening

OBJECTIVES

To determine the prenatal detection rate of abnormality (fetal anomaly or growth restriction) in pregnancies complicated by fetal trisomies 21, 18 and 13 in an obstetric population managed without routine biochemical or sonographic screening tests and to assess the perinatal outcome of these pregnancies.

SUBJECTS AND METHODS

This was a retrospective analysis of obstetric and neonatal data pertaining to infants born with trisomy 21, 18 or 13 (n = 82) diagnosed between 1989 and 1997 (23 762 deliveries).

RESULTS

Antenatal suspicion of aneuploidy, based on the detection of growth restriction or fetal anomaly, was present in 18.3% (11 of 60) of fetuses with trisomy 21, in 81.2% (13 of 16) of fetuses with trisomy 18, and in 83.3% (five of six) of fetuses with trisomy 13. The antenatal detection rates for growth restriction were accurate whereas the antenatal detection rates for fetal anomalies were poor. Intrauterine fetal death occurred in 18.8% of fetuses with trisomy 18 (three of 16) and in 50% (three of six) of cases of trisomy 13. For babies born alive with trisomy 18 or 13 the neonatal mortality was 93.8% (15 of 16). All cases of trisomy 21 fetuses survived beyond the perinatal period and the antepartum and intrapartum details of these pregnancies were unremarkable.

CONCLUSION

In obstetric practice without routine biochemical or sonographic screening tests the detection of findings suggestive of aneuploidy is low for trisomy 21, but is high for trisomies 18 and 13. These findings provide information for counseling about the antenatal, intrapartum, and neonatal course of these trisomies.

Expression of mRNA transcripts for ATP-sensitive potassium channels in human myometrium

The molecular mechanisms regulating human uterine quiescence and parturition are poorly understood. Potassium channels are central to regulation of cell membrane potential and contractility of smooth muscle. The aim of this study was to examine the expression of ATP-sensitive potassium channel (K(ATP) channel) subunits in human myometrium, and to investigate for possible differential expression of these subunits in myometrium obtained from three different functional states: (i) non-pregnant (NP); (ii) late pregnant not in labour (PNL); and (iii) late pregnant in labour (PL). RT-PCR detected the presence of mRNA for four subunits of K(ATP) channels (Kir6.1, Kir6.2, SUR1 and SUR2B) in the three tissue types. Quantitative analysis of these subunits was achieved with real-time RT-PCR using Lightcycler(TM) technology. This analysis showed that there were significantly higher levels of Kir6.1 and SUR2B transcripts in NP myometrium compared with those measured in myometrium obtained during pregnancy (P < 0.001). Lower levels of Kir6.2 and SUR1 mRNA expression were found, although higher transcript levels in NP myometrium (P < 0.05) were still observed. Our results indicate that the major K(ATP) channel expressed in human myometrium is composed of Kir6.1 and SUR2B, and that down-regulation of this channel may facilitate myometrial function during late pregnancy.

Corticosteroids and fetal vasculature: effects of hydrocortisone, dexamethasone and betamethasone on human umbilical artery

OBJECTIVE

To investigate the direct effects of corticosteroids on human umbilical artery resistance, in vitro.

DESIGN

Prospective laboratory study.

SETTING

University teaching hospital.

SAMPLES AND METHODS

Umbilical artery samples were obtained following normal, term deliveries (n = 50) and dissected rings were suspended for isometric recording under physiological conditions. The effects of hydrocortisone (10(-9) - 10(-4) M), dexamethasone (10(-9) - 10(-4) M) and betamethasone (10(-9) - 10(-4) M) on umbilical artery resistance were measured in vitro.

MAIN OUTCOME MEASURES

Changes in umbilical artery resistance, in vitro.

RESULTS

Hydrocortisone (n = 12) exerted a vasodilatory effect on human umbilical artery at all concentrations studied compared with vehicle control experiments (n = 12) (P < 0.0001). The mean net relaxant effect of hydrocortisone ranged from 11.77% (10(-9) M) to 57.01% (10(-4)). Both exogenous compounds, dexamethasone (n = 12) and betamethasone (n = 12), similarly exerted a significant relaxant effect on human umbilical artery tone (P < 0.05-0.01), compared with vehicle control experiments (n = 12). The mean net relaxant effect of dexamethasone ranged from 14.43% (10(-9) M) to 38.12% (10(-4)) and that of betamethasone ranged from 6.02% (10(-9) M) to 42.30% (10(-4)), in a cumulatively increasing fashion. There was a non-significant trend towards a greater vasodilatory effect of dexamethasone than betamethasone at lower bath concentrations studied.

CONCLUSION

Corticosteroids exert a direct and potent vasodilatory effect on human umbilical artery resistance in vitro, thus providing an explanation for the previously unexplained vascular effects associated with antenatal administration of corticosteroids.

Amino-terminal pro-brain natriuretic peptide in normal and hypertensive pregnancy

OBJECTIVES

To investigate serum levels of amino-terminal pro-brain natriuretic peptide (Nt pro-BNP) as an index of left-ventricular function in normal pregnancy and pregnancies complicated by hypertension and also to investigate levels in both primigravid and multigravid women.

METHODS

Women with hypertension in pregnancy (at least two readings of systolic blood pressure > 140 mm Hg and diastolic blood pressure > 90 mm Hg) (n = 24) and normotensive women (n = 42) were included in the study. Serum Nt pro-BNP was measured using an enzyme-linked immunosorbent assay technique.

RESULTS

The median serum Nt pro-BNP level in pregnancies complicated by hypertension was 420 fmol/L, which was significantly greater than that measured in samples obtained from normotensive women in pregnancy (340 fmol/L) (p = 0.03). There was a nonsignificant trend toward increased levels in proteinuric as compared to nonproteinuric hypertension in pregnancy. Multigravida had higher Nt pro-BNP levels (n = 26; median Nt pro-BNP = 358 fmol/L) than primigravida (n = 16; median Nt pro-BNP = 278 fmol/L) (p = 0.01) in association with normal pregnancy. Multigravida also demonstrated a dramatic rise in serum Nt pro-BNP levels in association with hypertension in pregnancy (n = 13; median Nt pro-BNP = 572 fmol/L) as compared to normal pregnancy (n = 26; median Nt pro-BNP = 358 fmol/L) (p = 0.009).

CONCLUSION

Serum Nt pro-BNP is elevated in women with hypertensive disorders of pregnancy, indicating elevated left-ventricular filling pressures. Measured serum levels in both normal and hypertensive pregnancy are higher in multigravida than in primigravida.

Expression and modulation of Rho kinase in human pregnant myometrium

There is little information outlining the role of Rho kinase, RhoA, and calcium sensitization in regulation of human uterine contractility during pregnancy. The aims of this study were to investigate the expression of RhoA, and the Rho kinases ROCK I and ROCK II in human pregnant myometrium, to evaluate the effects of Rho kinase inhibition on pregnant human myometrial contractility in vitro, and to compare these effects with those of the calcium channel blocker nifedipine. RT-PCR using primers for RhoA, ROCK I and ROCK II was performed on mRNA isolated from human pregnant myometrium. Isometric recording was performed in isolated myometrial strips obtained at Caesarean section. The effects of the Rho kinase inhibitor Y-27632 (1 nmol/l to 10 mmol/l), and nifedipine (1 nmol/l to 10 mmol/l), on oxytocin (0.5 nmol/l) induced contractions were measured and compared. Expression of RhoA, ROCK I and ROCK II mRNA was identified in human pregnant myometrium (n = 3). Y-27632 exerted a potent relaxant effect on myometrial contractility with a pD(2) value (+/- SEM) of 7.63 +/- 0.38 (n = 6). The maximum net relaxant effect (+/- SEM) was 72.3 +/- 6.1% (n = 6). Corresponding values for nifedipine were 7.24 +/- 0.48 (n = 6; P = 0.469) and 93.40 +/- 3.1% (n = 6; P = 0.028). Rho A/Rho kinase-mediated calcium sensitization may play role in the physiology of human parturition, and pharmacological inhibition of this pathway may therefore provide a novel approach to tocolysis for pre-term labour.

Uterine relaxant effects of cyclooxygenase-2 inhibitors in vitro

OBJECTIVE

To compare the effects of three cyclooxygenase-2 (COX-2) inhibitors: nimesulide, meloxicam, and celecoxib, which exhibit varying COX-2 selectivity, on contractile activity in pregnant (before and after labor) and nonpregnant human myometrial tissue in vitro.

METHODS

Isometric tension recording was performed under physiologic conditions in isolated myometrial strips obtained from 33 women undergoing hysterectomy or either elective or emergency cesarean section. The effects of cumulative additions of nimesulide, meloxicam, and celecoxib (between 1 nmol/L and 100 micromol/L) on myometrial contractility were measured, and values for -log(10) EC(50) and mean maximal inhibition were compared.

RESULTS

Nimesulide, meloxicam, and celecoxib exerted significant relaxant effects on contractility in nonpregnant, pregnant nonlabor, and pregnant labor myometrial strips. Values for -log(10) EC(50) values (+/- standard error of the mean) were as follows: nimesulide (nonpregnant) 5.14 +/- 0.93 (n = 6), (pregnant nonlabor) 4.91 +/- 0.75 (n = 6), and (pregnant labor) 5.84 +/- 0.35 (n = 6); meloxicam (nonpregnant) 6.53 +/- 0.57 (n = 6), (pregnant nonlabor) 4.80 +/- 0.71 (n = 6), and (pregnant labor) 5.62 +/- 0.21 (n = 6); celecoxib (nonpregnant) 6.15 +/- 0.99 (n = 6), (pregnant nonlabor) 7.08 +/- 0.98 (n = 6), and (pregnant labor) 7.25 +/- 0.99 (n = 3). Celecoxib exhibited greater potency than nimesulide or meloxicam (P < .01). The range of maximal relaxation values achieved in the three tissue types were as follows: nimesulide 68-70% (n = 18; P < .01), meloxicam 69-84% (n = 18; P < .01), and celecoxib 69-77% (n = 15; P < .01).

CONCLUSION

COX-2 inhibitors exert significant relaxation in human myometrium with a similar potency in nonpregnant and pregnant (before and after labor onset) tissues. Celecoxib, a COX-2 specific inhibitor, was more potent than nimesulide or meloxicam, COX-2 preferential inhibitors.

Cardiac troponin I and N-terminal pro-brain natriuretic peptide in umbilical artery blood in relation to fetal heart rate abnormalities during labor

The use of continuous fetal heart rate (FHR) recordings to monitor fetal well-being during labor is standard clinical practice in developed countries. Little is known about the relationship, if any, that exists between these FHR abnormalities and the fetal cardiac musculature and function. The aim of this study was to investigate umbilical artery serum levels of cardiac troponin I, a sensitive and specific marker of myocardial necrosis, and N-terminal pro-brain natriuretic peptide (pro-BNP), a sensitive marker of left ventricular dysfunction, in relation to FHR abnormalities. Umbilical artery blood samples were taken from 27 cases immediately after delivery of the infant. There was evidence of significant FHR abnormalities in 11 of these cases (group 2) and the FHR recording was normal in 16 cases (group 1). The mean N-terminal pro-BNP level in umbilical artery serum in group 2 was 413 fmol/L (SEM = 85) and in group 1 was 223 fmol/L (SEM = 28)(p = 0.022). There was no significant difference observed in cardiac troponin I levels between the two groups. Umbilical artery serum N-terminal pro-BNP is elevated in association with fetal heart rate abnormality in the late stage of labor. This finding suggests that some degree of cardiac compromise accompanies FHR abnormality.

Human chorionic gonadotrophin inhibition of pregnant human myometrial contractility

OBJECTIVE

To evaluate the effect of human chorionic gonadotrophin (hCG) on pregnant human myometrial contractility in vitro and to determine whether the hCG-elicited effect was oestrogen dependant.

METHODS

Isometric tension recording was performed under physiological conditions in isolated myometrial strips from biopsies obtained at elective caesarean section. The effect of cumulative additions of hCG (0.001, 0.01, 0.1, 1.0 and 10 iu/mL) on myometrial contractility was evaluated. Secondarily, the contractile activity of pregnant myometrium following hCG exposure was investigated in tissue pre-treated with beta-oestradiol.

RESULTS

hCG exerted a statistically significant relaxant effect on pregnant human myometrial tissue. The relaxant effect increased with increasing concentrations of hCG from 8.96% (SEM 2.06) (0.001 iu/mL hCG: P < 0.01 ) to a net cumulative total of 58.50% (SEM 3.74) (10 iu/mL hCG; P < 0.01). The relaxant effect was also time-dependant, increasing in magnitude throughout the duration of experiments. Beta-oestradiol did not significantly affect the response of myometrial tissue to hCG.

CONCLUSIONS

These results clearly demonstrate that hCG exerts a significant concentration-dependant relaxant effect on human myometrial tissue obtained rate in pregnancy. These findings outline an inhibitory physiological role of hCG on human myometrial contractility and raise the possibility of its potential use as a tocolytic.

Beta-3 versus beta-2 adrenergic agonists and preterm labour: in vitro uterine relaxation effects

OBJECTIVE

1. To investigate the effects of the selective beta-3 adrenoreceptor agonist, BRL 37344, on human pregnant myometrial contractility in vitro. 2. to compare these effects with those of the beta-2 adrenoreceptor agonist, ritodrine.

METHODS

Isometric tension recording was performed under physiological conditions in isolated myometrial strips from biopsies obtained at elective caesarean section. Following pre-incubation with oxytocin (10(-9) M), the effects of cumulative additions of BRL 37344 or ritodrine (10(-8)-10(-3.5) M) on myometrial contractility were investigated. Results were expressed as -log EC50 (pD2) and mean maximal inhibition achieved for both drug compounds.

RESULTS

BRL 37344 exerted a concentration dependant relaxant effect on myometrial contractions in all strips exposed [pD2, 7.26 (0.48) (SEM); mean maximal inhibition 61.98 (4.89%); n = 6]. Similarly, ritodrine exerted a concentration dependant inhibition of myometrial contractility in all strips exposed [pD2 = 7.40 (0.28); mean maximal inhibition 59.49 (3.97%); n = 6]. There was no significant difference between calculated pD2 values (P = 0.65) or mean maximal inhibition achieved (P = 0.79).

CONCLUSIONS

The beta-3 adrenoreceptor agonist BRL 37344 induced relaxation of human myometrial contractions with similar potency to that of the most commonly used tocolytic agent ritodrine. This raises the possibility that the novel beta-3 adrenoreceptor agonists may have potential as therapeutic agents for human preterm labour. In view of their reported reduced cardiovascular side effects their potential clinical use requires further evaluation.

Effect of parathyroid hormone-related peptide on human and rat myometrial contractility in vitro

OBJECTIVES

The aims of this study were primarily to investigate the effects of parathyroid hormone-related peptide (human fragment 1-34) on human nonpregnant and pregnant (nonlabor and labor) myometrial contractility in vitro and secondarily to compare these effects with those of parathyroid hormone-related peptide on rat myometrial contractility.

STUDY DESIGN

Isometric tension recording was performed under physiologic conditions in isolated myometrial strips obtained at hysterectomy and cesarean delivery and from Sprague-Dawley rats. The effect of cumulative additions of parathyroid hormone-related peptide (1, 10, and 100 nmol/L) on myometrial contractility was measured and the significance of results was assessed by 2-way analysis of variance.

RESULTS

Parathyroid hormone-related peptide exerted a statistically significant net relaxant effect on myometrial contractility in human nonpregnant myometrium (34.71%; P<.01), in human pregnant myometrium obtained before (18.27%; P <.05) but not after (10.32%; P>.05) the onset of labor, and in rat tissue (31.60%; P<.01).

CONCLUSIONS

Parathyroid hormone-related peptide exerts a relaxant effect on human and rat myometrial tissue. In human myometrium, sensitivity to parathyroid hormone-related peptide is reduced in pregnancy and abolished by the onset of labor.

Severe HELLP syndrome remote from term

A 27 year-old nulliparous woman was admitted to University College Hospital Galway with severe preeclampsia at 21 weeks 'gestation. In addition, there was evidence of HELLP syndrome with renal failure. A decision was made to end the pregnancy to save the mother's life. Labour was induced with misoprostol and vaginal delivery of a male stillborn fetus weighing 250 g was achieved after 19 hours. The condition of the patient improved gradually following delivery. Renal impairment, however, persisted postpartum. HELLP syndrome is a life-threatening complication of pregnancy which can only be cured by delivery. Other therapeutic modalities are only palliative but may improve the outcome for the very premature viable fetus. Conservative management is not an option when HELLP syndrome occurs long before fetal viability has been reached.

Cardiac troponin I in pre-eclampsia and gestational hypertension

OBJECTIVE

To investigate serum cardiac troponin I, a sensitive marker of cardiac myocyte damage, in normal pregnancy and pregnancies complicated by hypertension with and without significant proteinuria.

DESIGN

Prospective cross sectional study.

SETTING

University hospital delivery suite.

SAMPLE

Serum samples obtained from women in normal pregnancy and in pregnancies complicated by hypertension with and without significant proteinuria.

METHOD

Women with hypertension in pregnancy (at least two readings of systolic blood pressure > 140 mmHg and diastolic blood pressure > 90 mmHg) (n = 26) and normotensive women (n = 43) were included in the study. Serum cardiac troponin I was measured using Beckman Access immunoassay.

MAIN OUTCOME MEASURE

Serum cardiac troponin I level in the pregnancies complicated by hypertension (with and without significant proteinuria) compared with the levels measured in normotensive women.

RESULTS

The median serum cardiac troponin I level in pregnancies complicated by hypertension was 0.118 ng/mL (n = 26) which was significantly greater than that measured in samples obtained from normotensive women in pregnancy (0.03 ng/mL; n = 43) (P < 0.0001). There were higher median serum cardiac troponin I levels in hypertensive women with significant proteinuria (0.155 ng/mL; n = 6), compared with those without proteinuria (0.089 ng/mL; n = 20; P = 0.03).

CONCLUSION

Serum cardiac troponin I is elevated in women with hypertensive disorders of pregnancy indicating some degree of cardiac myofibrillary damage in these disorders.

Perinatal factors and preterm delivery in an Irish obstetric population

The aim of this study was to ascertain the incidence of preterm delivery, the associated etiological factors and consequent perinatal mortality in an Irish obstetrical population. All deliveries between 24 + 0 and 36 + 6 weeks of gestation that occurred during the five year period 1992-1996 were included in the study. The overall group of preterm deliveries was also analyzed separately as an early preterm group (24 + 0-31 + 6 weeks gestation) and a late preterm group (32 + 0-36 + 6 weeks gestation). The overall incidence of preterm delivery was 5.5% (n = 683) with 1% (n = 122) occurring in the early preterm group and 4.5% (n = 561) in the late preterm group. The etiological factors contributing to preterm delivery in our population together with their frequency of occurrence in both early and late preterm groups are outlined. Spontaneous unexplained preterm delivery, multiple pregnancy, and hypertensive disorders of pregnancy were the commonest etiological factors for preterm delivery. The perinatal mortality rate (PMR) was 57 per 1000 (n = 39) in the preterm group overall with a 213/1000 PMR in the early preterm group and a 23/1000 PMR in the late preterm group.

Development of an optimized feeding technology for dairy cows: improvement in resistance to ruminal proteases in the de novo-designed protein MB-1

We have previously reported on MB-1, a designer protein with potential application in animal nutrition. Having a high content of selected essential amino acids, MB-1 should provide limiting nutrients for animals and promote growth and production. However, the protein was found to have marginal conformational and proteolytic stability, and, thus, strategies for stabilizing MB-1 were elaborated. We discuss the synthesis of MB-1-Cys dimer, a protein with an intermolecular disulfide bridge. This mutant was exposed to Pronase E protease preparation as well as to proteases extracted from ruminal microbes. It was found that in both cases, MB-1-Cys dimer had a better resistance to proteolytic degradation than MB-1. Denaturation and hydrophobic dye binding studies revealed that this enhanced stability was not owing to conformational stabilization, but rather to changes in surface exposure as a consequence of dimerization. In particular, it was found that binding of ANSA to MB-1-Cys dimer was comparable to that observed for native, compact, natural proteins. We discuss the implications of these results for the design of transgenic protein production systems.