Preventing deaths from complications of labour and delivery

The process of labour and delivery remains an unnecessary and preventable cause of death of women and babies around the world. Although the rates of maternal and perinatal death are declining, there are large disparities between rich and poor countries, and sub-Saharan Africa has not seen the scale of decline as seen elsewhere. In many areas, maternity services remain sparse and under-equipped, with insufficient and poorly trained staff. Priorities for reducing the mortality burden are provision of safe caesarean section, prevention of sepsis and appropriate care of women in labour in line with the current best practices, appropriately and affordably delivered. A concern is that large-scale recourse to caesarean delivery has its own dangers and may present new dominant causes for maternal mortality. An area of current neglect is newborn care. However, innovative training methods and appropriate technologies offer opportunities for affordable and effective newborn resuscitation and follow-up management in low-income settings.

[Protection effect of recombiant human erythropoietin preconditioning against intrauterine hypoxic-ischemic brain injury and its influence on expression of caspase-3 protein in brain tissue]

OBJECTIVE

To investigate the effects of recombine human erythropoietin (rhEPO) on neural cells apoptosis and the expression of Caspase-3 protein in brain tissue of fetal rats after intrauterine hypoxic-ischemic brain injury.

METHODS

Forty-four Sprague-Dawley rats on 19 days of pregnancy were divided into rhEPO treated group, ischemia-reperfusion group and sham-operated group. Intrauterine hypoxic-ischemic injury of fetal rats was induced by bilateral occlusion of the utero-ovarian artery for 20 min. rhEPO (5000 U/kg) was injected into rats through caudal vein in rhEPO treated group while saline was injected into rats in hypoxic-ischemic group 30 min before hypoxic-ischemic injury. The brain samples in rhEPO treated group and hypoxic-ischemic group were obtained at 30 min, 3 h, 6 h, 24 h and 48 h respectively after artery clamping. There was no hypoxic-ischemic injury in sham-operated group, so the brain samples were obtained at 24 hours after sham operation. Neuroapoptosis in brain tissue was measured by TdT mediated dUTP-biotin nick end labeling (Tunel) staining. The expression of Caspase-3 protein was observed by immunohistochemistry.

RESULTS

The number of apoptosis cells in fetal rat hippocampus after intrauterine hypoxic-ischemic increased progressively with reperfusion. Compared with the I/R group, the number of apoptosis cells decreased in rhEPO treated group (P < 0.01). The expression of Caspase-3 increased rapidly after 3 hours from the reperfusion in the I/R group. Compared with the I/R group, there was less expression of Caspase-3 in rhEPO treated group (P < 0.01).

CONCLUSION

rhEPO showed the effects to inhibit the apoptosis of fetal neural cells and the expression of Caspase-3 protein due to intrauterine hypoxic-ischemic brain injury.

[A 25-year study (1983-2008) of children's health outcomes after hyperbaric oxygen therapy for carbon monoxide poisoning in utero]

Carbon monoxide (CO) poisoning during pregnancy can be fatal for the fetus, or cause bone malformations or encephalopathy, depending on the stage of pregnancy at which the poisoning occurs. Fewer cases of death and encephalopathy have been reported since the adoption of maternal hyperbaric oxygen (HBO) therapy in this setting, but these children's long-term psychomotor development and growth remains to be documented. A prospective single-center cohort study spanning 25 years (1983 - 2008) included all pregnant women living in the Nord-Pas-de-Calais region of France who received HBO for CO poisoning and who gave birth to a living child. A descriptive analysis of the women and children was performed first. A control group of children was created by matching with anonymous files from local authorities. The results of the children's compulsory health & development assessments were used to compare the two groups. 406 women were included in the study, of whom 6 were expecting twins. The psychomotor development of 412 children was monitored, up to the day 8 assessments in 388 cases, the year 2 assessments in 276 cases, and the year 6 assessments in 232 cases. Sixty children have not yet reached the age of 6 years. No significant differences in psychomotor or height/weight criteria (p > 0.05 for both) were found between the exposed and unexposed children. No malformations were reported. These findings support the use of HBO therapy for all expectant mothers exposed to CO poisoning. No specific follow-up of the children is necessary if their neonatal status is normal.

Time of birth and risk of neonatal death at term: retrospective cohort study

OBJECTIVE

To determine the effect of time and day of birth on the risk of neonatal death at term.

DESIGN

Population based retrospective cohort study.

SETTING

Data from the linked Scottish morbidity records, Stillbirth and Infant Death Survey, and birth certificate database of live births in Scotland, 1985-2004.

SUBJECTS

Liveborn term singletons with cephalic presentation. Perinatal deaths from congenital anomalies excluded. Final sample comprised 1,039,560 live births.

MAIN OUTCOME MEASURE

All neonatal deaths (in the first four weeks of life) unrelated to congenital abnormality, plus a subgroup of deaths ascribed to intrapartum anoxia.

RESULTS

The risk of neonatal death was 4.2 per 10,000 during the normal working week (Monday to Friday, 0900-1700) and 5.6 per 10 000 at all other times (out of hours) (unadjusted odds ratio 1.3, 95% confidence interval 1.1 to 1.6). Adjustment for maternal characteristics had no material effect. The higher rate of death out of hours was because of an increased risk of death ascribed to intrapartum anoxia (adjusted odds ratio 1.7, 1.2 to 2.3). Though exclusion of elective caesarean deliveries attenuated the association between death ascribed to anoxia and delivery out of hours, a significant association persisted (adjusted odds ratio 1.5, 1.1 to 2.0). The attributable fraction of neonatal deaths ascribed to intrapartum anoxia associated with delivery out of hours was 26% (95% confidence interval 5% to 42%).

CONCLUSIONS

Delivering an infant outside the normal working week was associated with an increased risk of neonatal death at term ascribed to intrapartum anoxia.

Mean platelet volume: Association with adverse neonatal outcome

The aim of the study was to investigate on a possible association between maternal mean platelet volume (MPV) and oxygen-metabolic changes in pregnancies affected by altered maternal-fetal Doppler velocimetry. We considered the altered maternal-fetal Doppler velocimetry group (n = 57) pregnant women admitted to our Institution for a pregnancy complication associated to the event Pre-eclampsia (PE) and intrauterine growth retardation (IUGR), with altered Doppler velocimetry in the umbilical artery ( UA) (high pulsatility index, absence or reverse end diastolic flow (ARED), blood flow cephalisation) and/or bilateral increased resistance in uterine arteries. Out of these cases, 25 pregnancies were complicated by PE and 32 pregnancies were complicated by IUGR. We included 145 normotensive third trimester pregnant women as a normal maternal-fetal Doppler velocimetry control group. From all women, 20 ml of whole venous blood was obtained from the antecubital vein soon after Doppler velocimetry evaluation. MPV was significantly higher in women with abnormal Doppler velocimetry compared to those with normal Doppler velocimetry (8.0 fl [7.0-8.7] vs. 9.1 fl [8.0-10.6], <0.001. Values are median [interquartiles]). We performed a ROC curve in order to find an MPV cut-off able to predict an uneventful event in Doppler velocimetry compromised fetuses (neonatal O(2) support > 48 hrs or intubation and/or pH < 7.2 at umbilical blood gas analysis (UBGA)). An MPV > or = 10 fl was significantly related to the former diagnostic endpoints compared to that of non-compromised fetuses (sensitivity: 45%, specificity: 89.7%, 95 CI: 18.8-66, p < 0.01). Our study suggests that pregnancies affected by Doppler velocimetry alterations, an MPV value > or = 10 fl may be associated with severe oxygen support and/or low UA ph at birth.

Influence of carbon monoxide poisoning on the fetal heart monitor tracing: a report of 3 cases

BACKGROUND

The diagnosis of carbon monoxide poisoning in the third trimester of pregnancy requires an index of suspicion, and the appearance of the fetal heart monitor tracing may help in this regard.

CASES

Three cases of third-trimester acute carbon monoxide poisoning occurred. In each pregnancy, the fetal heart monitor tracing on admission was correlated with the maternal carboxyhemoglobin level, and how the pattern changed following the institution of therapy was analyzed.

CONCLUSION

In all 3 cases, the initial fetal heart rate pattern demonstrated decreased variability with an elevated baseline and an absence of accelerations and decelerations. Within 45-90 minutes of treatment onset, the baseline fetal heart rate dropped by 20-40 beats per minute, the variability became moderate, and accelerations occurred. Absent accelerations with minimal variability, if caused by uteroplacental insufficiency, are usually preceded by recurrent decelerations. Absent accelerations with minimal variability in the absence of recurrent decelerations may suggest another cause, of which carbon monoxide intoxication can be added to the differential, especially since this disorder often has nonspecific clinical symptoms.

Hypoxic respiratory failure: etiology and outcomes at one referral center 2000 through 2005

OBJECTIVE

We calculated in a referral population of term and near-term infants with hypoxic respiratory failure (HRF) as a primary presenting problem the overall survival rate, the need for extracorporeal membrane oxygenation (ECMO) and the incidence of apparently irreversible disorders.

STUDY DESIGN

All infants >or=36-week gestation admitted at <or=72 h of age from 2000 through 2005 were identified. The worst (highest) oxygen index (OI) was calculated and outcomes were noted.

RESULTS

A total of 630 infants were reviewed and 315 infants were identified with primary diagnosis of HRF; four infants died before discharge. One hundred seventy-seven infants had OI <or=14; 71 had OI of 15 to 25; and 67 had OI of >25. A total of 32 infants received ECMO, including all four who died, two with histologic evidence of pulmonary malformations and two with septic shock.

CONCLUSION

Term or near-term infants with isolated HRF are likely to survive, given the low incidence of pulmonary disorders not supportable by inhaled nitric oxide or ECMO.

The effect of cerebral hypothermia on white and grey matter injury induced by severe hypoxia in preterm fetal sheep

Prolonged, moderate cerebral hypothermia is consistently neuroprotective after experimental hypoxia-ischaemia; however, it has not been tested in the preterm brain. Preterm (0.7 gestation) fetal sheep received complete umbilical cord occlusion for 25 min followed by cerebral hypothermia (fetal extradural temperature reduced from 39.4 +/- 0.3 to 29.5 +/- 2.6 degrees C) from 90 min to 70 h after the end of occlusion or sham cooling. Occlusion led to severe acidosis and profound hypotension, which recovered rapidly after release of occlusion. After 3 days recovery the EEG spectral frequency, but not total intensity, was increased in the hypothermia-occlusion group compared with normothermia-occlusion. Hypothermia was associated with a significant overall reduction in loss of immature oligodendrocytes in the periventricular white matter (P < 0.001), and neuronal loss in the hippocampus and basal ganglia (P < 0.001), with suppression of activated caspase-3 and microglia (isolectin-B4 positive). Proliferation was significantly reduced in periventricular white matter after occlusion (P < 0.05), but not improved after hypothermia. In conclusion, delayed, prolonged head cooling after a profound hypoxic insult in the preterm fetus was associated with a significant reduction in loss of neurons and immature oligodendroglia, with evidence of EEG and haemodynamic improvement after 3 days recovery, but also with a persisting reduction in proliferation of cells in the periventricular region. Further studies are required to evaluate the long-term impact of cooling on brain growth and maturation.

[Influence of antenatal administration of corticoids on heart activity--case report]

OBJECTIVE

to draw attention to possible influencing of cardiotocographic recording of antenatal administration of corticoids, on the use of Doppler ultrasonographic parameters in the diagnostics of hypoxia-endangered fetus.

DESIGN

Case report.

SETTING

Mother and Child Care Institute of Prague.

METHOD

Case report.

CONCLUSION

Antenatal administration of corticoids is presently an inherent part of therapeutic management of premature delivery. This administration significantly diminishes morbidity and mortality of immature newborns. Nevertheless, their administration results in changing intrauterine behavior of the fetus and his/her heart activity. These changes may be mistakenly diagnosed as signs of evolving hypoxia. For the evaluation of acute condition of the fetus and obtaining help in decision making how the further management of delivery should be done, Doppler ultrasonographic examination of maternal, fetus-maternal and fetal circulation may prove useful.

Amniotic fluid embolism: an obstetric emergency

AFE is an unpredictable, unpreventable, and, for the most part, an untreatable obstetric emergency. Management of this condition includes prompt recognition of the signs and symptoms, aggressive resuscitation efforts, and supportive therapy. Any delays in diagnosis and treatment can result in increased maternal and/or fetal impairment or death. Whereas once the invariable outcome of AFE was death of the mother, today the prognosis is somewhat brighter thanks to increased awareness of the syndrome and advances in intensive care medicine. In any case, intensive care nurses are called on to provide physical, life-saving care to the patient and her fetus. Both during and after the event, supportive care must be administered to the patient's family members, who are dealing with crisis and loss.

Four cases of the ex utero intrapartum treatment (EXIT) procedure: anesthetic implications

The ex utero intrapartum treatment (EXIT) procedure is a method of maintaining utero-placental circulation during cesarean section to gain time to secure a potentially obstructed fetal airway. Four cases of the EXIT procedure are described with special reference to the maternal anesthetic technique. Deep volatile anesthesia (approximately 2 MAC) with isoflurane or sevoflurane for a prolonged period of time, in three cases in combination with an intravenous nitroglycerin infusion, was used to ensure a fully relaxed uterus during the procedure. All mothers were maintained hemodynamically stable with preserved utero-placentary perfusion. It was possible to intubate the tracheas of two fetuses, whereas in the other two tracheostomies had to be performed. Fetal gas exchange was not negatively affected during the EXIT procedure as evidenced by normal blood gas values in the umbilical artery at the time of delivery. After reducing the concentration of volatile anesthetic, delivery of the neonate and administration of oxytocin, uterine contractility was promptly re-established and there were no signs of uterine atony in the postoperative period. All four neonates survived the procedure without complications.

Resuscitation with 100% O(2) does not protect the myocardium in hypoxic newborn piglets

BACKGROUND

Perinatal asphyxia is associated with cardiac dysfunction secondary to myocardial ischaemia. Cardiac troponin I (cTnI) is a marker of myocardial necrosis. Raised concentrations in the blood are related to perinatal asphyxia and increased morbidity.

OBJECTIVE

To assess porcine myocardial damage from enzyme release during hypoxaemia induced global ischaemia, and subsequent resuscitation with ambient air or 100% O(2). To investigate whether CO(2) level during resuscitation influences myocardial damage.

DESIGN

Newborn piglets (12-36 hours) were exposed to hypoxaemia by ventilation with 8% O(2) in nitrogen. When mean arterial blood pressure had fallen to 15 mm Hg, or base excess to < -20 mmol/l, the animals were randomly resuscitated by ventilation with either 21% O(2) (group A, n = 29) or 100% O(2) (group B, n = 29) for 30 minutes. Afterwards they were observed in ambient air for another 150 minutes. During resuscitation, the two groups were further divided into three subgroups with different CO(2) levels.

ANALYSIS

Blood samples were analysed for cTnI, myoglobin, and creatine kinase-myocardial band (CK-MB) at baseline and at the end of the study.

RESULTS

cTnI increased more than 10-fold (p < 0.001) in all the groups. Myoglobin and CK-MB doubled in concentration.

CONCLUSION

The considerable increase in cTnI indicates seriously affected myocardium. Reoxygenation with 100% oxygen offered no biochemical benefit over ambient air. CK-MB and myoglobin were not reliable markers of myocardial damage. Normoventilation tended to produce better myocardial outcome than hyperventilation or hypoventilation.

[Congenital heart disease and acquired valvular lesions in pregnancy]

BACKGROUND

In Germany, about 6,000 pregnancies in women with grown-up congenital heart disease or acquired valvular lesions are expected per year. The pregnancy-related physiology is characterized by a 50% increase in plasma volume and a 25% increase in erythrocyte volume. The cardiac output increases by 40% due to 30% increase in stroke volume and 10% increase in heart rate during the first half, and 10% increase in stroke volume but 30% increase in heart rate during the second half of pregnancy. As a consequence of the decrease of systemic vascular resistance, the systolic and, even more, the diastolic blood pressures are reduced during approximately the first 20 weeks of pregnancy.

UNCORRECTED CONGENITAL LESIONS

Women with uncorrectable congenital heart disease, congestive heart failure (NYHA III and IV) despite optimized medical treatment after palliative surgery, or pulmonary vascular resistances > 800 dyn x s x cm(-5) should be advised against pregnancy. The presence of congestive heart failure or persistent cyanosis in the mother are the most important predictors of fetal hypoxia. Patients with pretricuspid shunts (e.g., atrial septal defect [ASD]) are at low risk of a hemodynamic deterioration or first onset of arrhythmias. In the rare case of a marked clinical deterioration, catheter-based closing of the shunt is the first-line treatment. Also, ventricular septal defects and persistent ducti arteriosi are usually well tolerated during pregnancy, as they are highly resistant to flow. In some cases, arrhythmias may occur. The prognosis is less favorable, if myocardial compromise has already been present before pregnancy. The fatal complication rate correlates closely with the degree of congestive heart failure. In aortic coarctation, development of severe hypertension, myocardial decompensation, aortic dissection, and cerebral hemorrhage have been reported in 2.3% of cases. To prevent aortic dissection and rupture of cerebral vascular aneurysms, patients should be advised to reduce their physical activity and have their blood pressure controlled closely. If, during pregnancy, a therapeutic intervention is unavoidable, stent placement is the therapy of choice. The maternal complication rate is low in pulmonary artery stenosis. Hemodynamically significant stenoses should be treated before pregnancy. In the rare case of progressive right heart failure or cyanosis during pregnancy, balloon valvotomy is the first-line therapeutic option.

CONGENITAL HEART DISEASE WITH PRIOR PALLIATION

Women with incomplete correction of a tetralogy of Fallot or significant residual gradients or shunts carry a particular risk of myocardial deterioration. A maternal hematocrit > 60%, an arterial O(2) saturation < 80%, markedly elevated right ventricular pressures, and the former presentation of syncopes are indicators of a poor prognosis. Fatal complication rates have been reported in 3-17% of cases. Other cyanotic lesions have been linked with a poor maternal and fetal prognosis. A 32% incidence of severe cardiovascular complications (pump failure, thromboembolic events, life-threatening arrhythmias, infective endocarditis) has been reported during 96 pregnancies of women with cyanotic heart disease. In addition, the frequency of abortions, premature birth, fetal distress, and congenital malformation of the child was 57%.

ACQUIRED VALVE LESIONS

Mitral stenosis is the lesion that most frequently requires therapeutic intervention during pregnancy, as the transmitral flow increases and time of diastole decreases during pregnancy due to the increase in cardiac output and heart rate. A consequent increase in mean pulmonary artery pressure by approximately 50% and a deterioration by one to two NYHA classes must be expected. While patients with a mitral orifice area > 1.5 cm(2) can usually be treated medically, more advanced mitral stenoses often require percutaneous mitral balloon valvotomy, a procedure with a very low complication rate in experienced centers. A chronic mitral or aortic regurgitation without jeopardized myocardial function is usually well tolerated during pregnancy, as the drop in peripheral vascular resistance results in a favorable left ventricular impedance, which reduces the transmitral regurgitant fraction and improves left ventricular antegrade ejection. Moreover, the increase in heart rate limits diastolic transaortic regurgitation. Hemodynamically advanced aortic stenosis is rare among patients in child-bearing age. The hemodynamic changes during pregnancy result in a decrease of the transaortic flow per time and thus in a decrease of the transaortic pressure loss. On the other hand, myocardial wall stress and oxygen consumption are significantly increased. If aortic valve orifice area is > 1.5 cm(2), the hemodynamic situation is usually well tolerated during pregnancy. In the case of more advanced aortic stenosis, there is a considerable risk of myocardial decompensation. The development of symptoms such as dyspnea, near syncopes or syncopes, and arrhythmias are indicators of a complicated course. If treatment is unavoidable, aortic valve replacement is the therapy of choice.

ORAL ANTICOAGULATION

With respect to anticoagulation during pregnancy, there is an ongoing debate about the potential risk and benefit of phenprocoumon, standard heparins, and low molecular heparins. Withdrawal of any anticoagulation results in the most favorable fetal outcome, oral anticoagulation throughout pregnancy in the best prognosis for the mother. An individual approach by an experienced center taking all therapeutic options into account is probably the best strategy.

Impact of education and training on neonatal resuscitation practices in 14 teaching hospitals in India

The impact of a neonatal resuscitation programme (NRP) on the incidence, management and outcome of birth asphyxia was evaluated in 14 teaching hospitals in India. Two faculty members from each institution attended a neonatal resuscitation certification course and afterwards trained staff in their respective hospitals. Each institution provided 3 months pre-intervention and 12 months post-intervention data. Introduction of the NRP significantly increased awareness and documentation of birth asphyxia, as judged by an increased incidence of asphyxia based on apnoea or gasping at 1 and 5 minutes (p < 0.001 and < 0.01, respectively). A significant shift towards more rational resuscitation practices was indicated by a decline in the use of chest compression and medication (p < 0.001 for each), and an increase in the use of bag and mask ventilation (p < 0.001). Although overall neonatal mortality did not decrease, asphyxia-related deaths declined significantly (p < 0.01).

Risk management and electronic fetal monitoring: decreasing risk of adverse outcomes and liability exposure

Electronic fetal monitoring (EFM) has the potential to promote fetal health and improve neonatal status at birth; however, EFM as a stand-alone tool is ineffective in avoiding preventable adverse outcomes. It is effective only when used in accordance with published standards and guidelines by professionals skilled in correct interpretation and when appropriate timely intervention is based on that interpretation. Interpretation and intervention are best accomplished as a collaborative perinatal team rather than individual activity. Only in these circumstances can EFM optimally contribute to fetal well-being and subsequent neonatal health. Risk management strategies to decrease potential liability are presented that can be accomplished with careful planning and collaboration among perinatal team members.

Changes in fetal plasma adenosine and xanthine concentrations during fetal asphyxia with maternal oxygen administration in ewes

In this study, we measured fetal plasma adenosine and xanthine concentrations during and after severe asphyxia, and investigated the key issues related to oxygen therapy. Asphyxia was induced by occluding the umbilical cord for 5 minutes in 6 fetal sheep with and without the administration of oxygen to the ewe. Plasma adenosine concentration increased significantly during cord occlusion in the all fetuses, and the differences between the values in the fetuses with and without maternal oxygen administration was not significant. By 30 minutes after cord release, plasma adenosine concentration in all fetuses had returned to levels similar to those at the start of the experiment. Plasma xanthine concentration also increased during cord occlusion in all fetuses. However, 30 minutes after cord release, plasma xanthine concentration had decreased significantly in fetuses without additional oxygen, while it did not change significantly in fetuses with maternal oxygen administration. Thus, we speculated that maternal oxygen administration before fetal asphyxia may not contribute to additional ATP stores in fetal organs and may produce oxygen free radicals following asphyxia.

Systematic review of therapy after hypoxic-ischaemic brain injury in the perinatal period

Objectives were to identify and to evaluate controlled trials of interventions for term infants developing hypoxic-ischaemic encephalopathy. Five randomized trials concerning prophylactic anticonvulsant therapy for neonatal HIE were identified. There were methodological problems with all of them, and meta-analysis of barbiturate prophylaxis showed no significant effect on death or disability. One randomized trial of allopurinol showed short-term benfits, but was too small to test death or disability. One small randomized trial of hypothermia found no adverse effects, but was too small to examine death or disability. No adequate trials of dexamethasone, calcium channel blockers, magnesium sulphate, or naloxone have yet been completed, but pilot studies in infants have shown the risks of magnesium sulphate and calcium channel blockers.

Cooling the newborn after asphyxia - physiological and experimental background and its clinical use

Many years of experimental work on hypoxic-ischaemic injury have supported the hypothesis that cooling the body and brain after the primary injury offers permanent neuroprotection. Clinically, the question of how late cooling can start after the insult and still have a protective effect is important and not fully investigated. Pilot studies in human adults initiated cooling after 10-18 h (trauma, stroke), however animal data suggest cooling is not effective if started later than 6 h. There might be a threshold for 'cooling dose' - by depth or duration - to achieve permanent protection. Hypothermia must be administered with understanding of the extensive physiological effects. Different enzymes have different sensitivity to changes in temperature, hence some effects may be beneficial and some deleterious. Hypothermia and cardiovascular responses and coagulation needs careful monitoring.

Novel treatments after experimental brain injury

Perinatal hypoxic-ischaemic encephalopathy(HIE) is being studied in laboratory models that allow the delayed cascade of events triggered by the energetic insult to be examined in detail. The concept of the 'excitotoxic cascade' provides a conceptual framework for thinking about the pathogenesis of HIE. Major events in the cascade triggered by hypoxia-ischaemia include overstimulation of N-methyl-D-aspartate type glutamate receptors, calcium entry into cells, activation of calcium-sensitive enzymes such as nitric oxide synthase, production of oxygen free radicals, injury to mitochondria, leading in turn to necrosis or apoptosis. New experimental approaches to salvaging brain tissue from the effects of HIE include inhibition of neuronal nitric oxide synthase, administration of neuronal growth factors, and inhibition of the caspase enzymes that execute apoptosis. Recent experimental work suggests that these approaches may be effective during a longer 'therapeutic window' after the insult, because they are acting on events that are relatively delayed. Application of modest hypothermia may allow these agents to be neuroprotective at even longer intervals after hypoxia-ischaemia.

Selection of babies for intervention after birth asphyxia

Based on animal experiments, the therapeutic window for neonates with signs of perinatal hypoxia-ischaemia is probably less than 6 h, and early selection of patients is of utmost importance. In term neonates, fetal heart rate and blood flow patterns, the Apgar score, and other clinical scoring systems are insufficient to select patients for intervention, whereas umbilical artery pH<7.0 combined with umbilical arteriovenous differences in PCO(2), lactate/pyruvate ratios in cord blood, and CSF interleukin-1beta have a better predictive value. At present, neurophysiological methods such as (amplitude-integrated) EEG and evoked potentials have the best predictive value. In preterm neonates, lactate/pyruvate and uric acid measurements in cord blood, as well as neurophysiology appear to be helpful to predict brain injury, and might be used to select patients for intervention.

Fetal oxygenation, assessment of fetal well-being, and obstetric management of the pregnant patient with asthma

Asthma is the most common chronic respiratory disease affecting pregnant women. To provide the best obstetric care, it is necessary to understand fetal oxygenation and how it can be affected by maternal asthma. During pregnancy, fetal well-being should be closely monitored, and asthma care should be carefully integrated with obstetric care. Optimal fetal assessment includes establishing gestational age, assessment of fetal growth, and monitoring fetal activity. Evaluation for high-risk patients may include the non-stress test, contraction stress test, or biophysical profile.

Keeping a cool head, post-hypoxic hypothermia--an old idea revisited

Hypoxia-ischaemia produces permanent brain damage by processes that continue for many hours after reoxygenation/reperfusion. This provides a window of opportunity for therapy aimed at preventing further loss of brain cells. Reducing brain temperature by 2-6 degrees C for 3-72 h after reoxygenation/reperfusion has been shown to reduce brain damage by 25-80% in controlled trials with six different neonatal animal models of hypoxia-ischaemia. No adverse effects from mild hypothermia have been documented. The mechanisms of protection are unknown but may include a reduction in extracellular excitotoxic amino acids, reduced nitric oxide synthesis and inhibition of apoptosis. Mild hypothermia is currently the most promising clinically feasible neural rescue therapy for full-term infants at risk of developing hypoxic-ischaemic encephalopathy, but clinical use must be restricted to approved trial protocols.

Intrapartum fetal monitoring

There is an undisputed need for close fetal surveillance during labour. The transition to extra-uterine life has a number of potential hazards-many of which may be averted by appropriately timed intervention. It is evident, however, that not all intrapartum sequelae can be avoided despite intensive surveillance and increasingly high rates of intervention.

Iatrogenic radiant heat burns in severely asphyxic newborns

We report two cases of newborns who developed second-degree burns following resuscitation under infra-red heating lamps. Both infants were asphyxic and suffered from insufficient peripheral circulation which, combined with the long duration of the exposure to the light, contributed to the development of the lesions. Both infants died shortly after birth for reasons other than the burns.

Pregnancy complicated by Ebstein's anomaly: oxygen administration to mother for chronic fetal hypoxemia. A therapeutic case report

For chronic fetal hypoxia due to maternal Ebstein's anomaly, oxygen was administered daily to the mother by mask for 105 days. At 20 weeks of gestation, umbilical venous blood gases in room air showed pH 7.42, PO2 25.7 mm Hg, PCO2 33.7 mm Hg and O2 saturation 48.7%, and changed to 7.45, 39.1 mm Hg, 25.9 mm Hg and 77.4% on 3 liters/min of oxygen inhalation by mask, respectively. The PO2 of the maternal arterial blood gases increased to 30 mm Hg on oxygen administration at 15 weeks of gestation, but at 25 weeks of gestation the PO2 increased by only about 10 mm Hg. At 30 weeks, intrauterine growth retardation was suspected. Just after the second puncture of the umbilical cord at 31 weeks and 3 days of gestation, 80 bpm fetal bradycardia occurred for several minutes without recovery and emergency cesarean section was done under the general anesthesia.

Weakness in the newborn calf

The peak time period for the average beef producer to experience the majority of calf losses has consistently been from the time of birth through the first seven days of life. Weakness is a principal clinical sign of diseases or conditions responsible for mortality including birth trauma, prematurity or dysmaturity, congenital malformations, metabolic defects, intrauterine infection, anoxia or hypoxia, hypothermia, starvation, extremes in birth weight, and post-natal infection. This article discusses anoxia/hypoxia and septicemia in greater detail because of their involvement as a common cause of weakness in the newborn calf.

Intrauterine resuscitation in the severely distressed fetal dog

Severe fetal distress was produced in 16 fetal dogs by successive and/or prolonged occlusion of the maternal abdominal aorta in an acute surgical preparation, and was characterized in fetal arterial blood of 7.06 for pH, 10 mm Hg for O2, 127 mm Hg for CO2, and fetal heart rate decelerations. Five fetuses recovered spontaneously in utero and delivered normally; 3 needed maternal oxygenation before delivery; 3 suddenly died in utero; 5 fetuses were delivered while still alive in utero when the tpH reached 6.85, and eventually expired. Intrauterine recovery and resuscitation was effective in some fetuses.

Glucose, lactic acid, and perinatal hypoxic-ischemic brain damage

Investigations suggest that hyperglycemia, superimposed on hypoxia-ischemia or cerebral ischemia, accentuates brain damage in adult experimental animals and humans, but not in immature animals. Fundamental differences in the immature and adult brain, which account for the age-specific paradox, are discussed. Based on currently available data, we recommend that glucose supplementation not be curtailed during labor and delivery of asphyxiated human infants; on the contrary, glucose therapy may substantially reduce hypoxic-ischemic brain damage.

Development of the coronary vasculature in hypoxic fetal rats treated with a purified perfluorocarbon emulsion

OBJECTIVE

To quantitatively define the coronary vascular bed in the 21-day-old rat fetus with gestational normoxia and hypoxia; to determine if maternal supplemental oxygen and/or oxygen-carrying perfluorocarbons (PFCs) influence development of coronary vessels; and to compare the results using purified and unpurified PFC treatment.

DESIGN

Unilateral uterine artery ligation was introduced on gestational day 17 in pregnant animals. Control fetuses were from unligated uterine horns. Experimental intervention occurred during gestational days 17 to 21, with fetuses recovered on day 21. Developing coronary vessels were analyzed quantitatively via light microscopy.

ANIMALS

Pregnant Sprague Dawley rats.

INTERVENTIONS

Following ligation, pregnant rats received no further treatment, supplemental oxygen inhalation alone, or daily intravenous purified PFC treatment, with or without supplemental oxygen.

MAIN RESULTS

Hypoxia caused an increase in resorptions (P less than 0.001), and decreased fetal body weight (P less than 0.001) and heart weight (P less than 0.05). Although the area occupied by developing coronary vessels (sinusoids) was substantially increased, maturation was unchanged. Oxygen supplementation alone did not appreciably influence fetal resorptions or body weight in ligated horns, but did increase fetal heart weight. Sinusoidal area decreased (P less than 0.01), with no effect on sinusoidal maturity. Purified PFC treatment did not alter maternal weight gain or fetal body weight, and moderately decreased resorptions in ligated horns. Fetal heart weight was augmented with purified perflurochemical, while unpurified perfluorochemical treatment diminished heart weight. Both PFC emulsions substantially decreased sinusoidal area.

CONCLUSIONS

Perflurocarbon treatment associated with supplemental oxygen is capable of improving the hypoxic effects on fetal heart and coronary vessel development if the emulsion used is appropriately purified.

Extracorporeal membrane oxygenation (ECMO) for non-ECMO intensive care nurseries

An extracorporeal membrane oxygenation (ECMO) centre has been established in the sole outborn-only level 3 nursery in Melbourne. In the absence of other guidelines, an infant may qualify for ECMO if the expected mortality, based on assessment of the severity of hypoxia, exceeds 80%. However, for a non-ECMO centre, this involves the additional hazard of transport for an already critically-ill infant. The aim of this study was to determine the predictors of at least 80% mortality in babies who might have qualified for ECMO but who were cared for in a non-ECMO level 3 nursery. Regardless of the severity or duration of hypoxia, we were unable to identify a group of infants whose mortality exceeded 80%. Since outborn infants were disproportionately over-represented amongst those who might qualify for ECMO, it would be advisable to admit preferentially those born outside the level 3 perinatal centres who might qualify for ECMO directly to the ECMO centre. For infants born within our level 3 perinatal centre, it is recommended not to transfer those who might qualify based on data from other centres until the exact role of ECMO is determined. Alternatively, a randomized controlled trial of transfer versus non-transfer to the ECMO centre for severely hypoxic infants cared for in non-ECMO level 3 nurseries could be considered.

The influence of oxygen administration to the mother during labor on the fetal transcutaneously measured carbon-dioxide partial pressure

The aim of this study was to plot the course of the transcutaneously measured PCO2 (tcPCO2) in the fetus during oxygenation of the mother. In our examination 35 parturients with a suspicious or pathologic CTG were given pure oxygen for 10 minutes at a flow speed of 10 l/min. The fetal tcPCO2 was measured with a TCM 3 measuring device from Radiometer. The measuring temperature was 41 degrees C. The fetal tcPCO2 was 67.2 +/- 3.9 mmHg before the O2 application, during the O2 application it was 67.3 +/- 14.1 mmHg and for the period after the O2 application we found an average measurement of 66.7 +/- 13.9 mmHg. Further we investigated whether, depending on the original levels of the fetal tcPCO2 an O2 application to the mother had a measurable effect on the fetal tcPCO2 levels. The average levels of the tcPCO2 in the fetuses with pathological original levels of greater than or equal to 60 mmHg or with normal levels of less than 60 mmHg did not show any significant differences before, during or after the O2 application. Our own results and reports given in the literature about an increase in the fetal O2 partial pressure during maternal oxygenation lead to the conclusion that in cases with fetal hypoxia, the O2 application to the mother--in addition to other measures for intrauterine reanimation or speedy termination of labor--could be of advantage.

Prevention, recognition, and treatment of perinatal asphyxia

Management of perinatal asphyxia is one of those rare opportunities in clinical medicine when death or life-long disability can be prevented with several minutes of skillful and judicious action. Fetal and neonatal asphyxia is approached most successfully as a joint obstetric, pediatric, and anesthetic effort. This article reflects the team approach to perinatal asphyxia.

[Placental scintigraphy--a diagnostic method for evaluating indications for hyperbaric oxygenation in pregnant women with high risk of perinatal pathology]

At most, 40 pregnant females at a high risk for fetal perinatal pathology underwent clinical investigation, ultrasonic scanning of the placenta, recording of the fetal electro- and phonocardiography, the evaluation of the placental levels of lactogen and estradiol and thermoresistant alkaline phosphatase changes of the values considered who were then treated with hyperbaric oxygenation (HBO) under the control of dynamic placental scintigraphy. Based on the placentographic findings, the authors distinguished from the whole of the risk-group the patients whose pattern of uteroplacental blood flow response to the treatment was beneficial and therefore the HBO treatment for fetoplacental insufficiency was advisable.

[Continuous respiratory therapy of newborn and premature infants with respiratory disorders]

2216 newborns and prematures with respiratory distress of different underlying diseases were treated with long term respiratory therapy from 1. Jan. 1975 to 31. Dec. 1985. One part of the patients were born in our hospital, the other part of them were transported from outside. The rate of prematures was 81.2%. The respiratory therapy was applied in 1813 cases because of pulmonary diseases (group 1.), while in 403 cases the respiratory troubles were extrapulmonary in origin (group 2.). The diseases in the first group were as follows: hyaline membrane disease in 482 cases (27.30%), intrauterine pneumonia in 634 cases (34.64%), postnatal pneumonia in 291 cases (15.90%), meconium aspiration syndrome in 110 cases (6.01%), severe RDS-II in 158 cases (8.63%), pulmonary immaturity in 116 cases (6.35%), persistent fetal circulation in 21 cases (1.15%) and pulmonary aplasia on the left in 1 case (0.021%). In the second group the greatest part of the cases were treated for neurological disturbances. We discuss the indications of different types of respiratory therapy and the complications as well. The survival rate was in the first group 59.3%, while in the second only 16.9%. Therefore the respiratory therapy seems to be more effective in the pulmonary diseases of the newborns. The mortality rate and the rate of severe complications were lower among inborn babies because of the early application of the respiratory therapy.

[Indications for cesarean section in the delivery of the 2d twin after vaginal birth of the 1st twin]

Cesarean section for delivery of twin B after vaginal delivery of twin A is a rare and extraordinary event in obstetrics. From 1.1.82-31.12.86, from a total number of 9357 deliveries, 133 pairs of twins (1.4%) were born. In 3 cases (2.2%) twin B was delivered by cesarean section after vaginal delivery of twin A. Taking into account 51 published cases in the recent literature, the indications for cesarean delivery of the second twin were demonstrated and compared. In the main, emergency situations presenting more than one obstetrical complication were responsible for this uncommon practice. Regarding the results presented, cesarean section of the second twin after vaginal delivery of the first-born seems to be a proven procedure to deliver the second twin faster and more safely than by hazardous vaginal manipulations, especially in obstetrical emergency situations.

Maternal oxygen therapy for intrauterine growth retardation

Humidified oxygen (55%) was administered continuously through a face mask to 5 patients whose pregnancies (4 singleton and 1 twin) were all complicated by severe intrauterine growth retardation, oligohydramnios, high blood-flow impedance in the fetal aorta and umbilical artery, and low mean blood-velocity in the fetal thoracic aorta. All the fetuses were hypoxic and 2 were acidotic. After maternal hyperoxygenation, the fetal pO2 increased to within or near the normal range, and resulted in a sustained increase in the mean blood-velocity in the fetal thoracic aorta. 5 fetuses survived with minimum neonatal morbidity. The effect of maternal hyperoxygenation on the fetal pO2 in such cases may prove to be a useful method of assessing placental function and guiding management.