Intrapartum fetal heart rate patterns in infants (> or =34 weeks) with poor neurological outcome

Prevalence of hearing impairment in neonatal encephalopathy due to hypoxia-ischemia: a systematic review and meta-analysis

BACKGROUND

This systematic review was undertaken to estimate the overall prevalence of hearing impairment in survivors of neonatal HIE.

METHODS

PubMed, EMBASE, CINAHL, EMCARE and Cochrane databases, mednar (gray literature) were searched till January 2023. Randomized controlled trials and observational studies were included. The main outcome was estimation of overall prevalence of hearing impairment in survivors of HIE.

RESULTS

A total of 71studies (5821 infants assessed for hearing impairment) were included of which 56 were from high income countries (HIC) and 15 from low- or middle-income countries (LMIC). Overall prevalence rate of hearing impairment in cooled infants was 5% (95% CI: 3-6%, n = 4868) and 3% (95% CI: 1-6%, n = 953) in non-cooled HIE infants. The prevalence rate in cooled HIE infants in LMICs was 7% (95% CI: 2-15%) and in HICs was 4% (95% CI: 3-5%). The prevalence rate in non-cooled HIE infants in LMICs was 8% (95% CI: 2-17%) and HICs was 2% (95% CI: 0-4%).

CONCLUSIONS

These results would be useful for counseling parents, and in acting as benchmark when comparing institutional data, and while monitoring future RCTs testing new interventions in HIE. There is a need for more data from LMICs and standardization of reporting hearing impairment.

IMPACT

The overall prevalence rate of hearing impairment in cooled infants with HIE was 5% (95% CI: 3-6%) and 3% (95% CI: 1-6%) in the non-cooled infants. The prevalence rate in cooled HIE infants in LMICs was 7% (95% CI: 2-15%) and in HICs was 4% (95% CI: 3-5%). The prevalence rate in non-cooled HIE infants in LMICs was 8% (95% CI: 2-17%) and HICs was 2% (95% CI: 0-4%). These results would be useful for counseling parents, and in acting as benchmark when comparing institutional data, and while monitoring future RCTs testing new interventions in HIE.

Abnormal fetal heart rate patterns caused by pathophysiologic processes other than fetal acidemia

Fetal acidemia is a common final pathway to fetal death, and in many cases, to fetal central nervous system injury. However, certain fetal pathophysiological processes are associated with significant category II or category III fetal heart rate changes before the development of or in the absence of fetal acidemia. The most frequent of these processes include fetal infection and/or inflammation, anemia, fetal congenital heart disease, and fetal central nervous system injury. In the presence of significant category II or category III fetal heart rate patterns, clinicians should consider the possibility of the aforementioned fetal processes depending on the clinical circumstances. The common characteristic of these pathophysiological processes is that their associated fetal heart rate patterns are linked to increased adverse neonatal outcomes despite the absence of acidemia at birth. Therefore, in these cases, the fetal heart rate patterns may provide more insight about the fetal condition and pathophysiology than the acid-base status at birth. In addition, as successful timing of intrapartum interventions on the basis of evolution of fetal heart rate patterns aims to prevent fetal acidemia, it may not be logical to continue to use the fetal acid-base status at birth as the gold standard outcome to determine the predictive ability of category II or III fetal heart rate patterns. A more reasonable approach may be to use the umbilical cord blood acid-base status at birth as the gold standard for determining the appropriateness of the timing of our interventions.

Correlation between fetal heart rate evolution patterns and magnetic resonance imaging findings in severe cerebral palsy: A longitudinal study

OBJECTIVE

To investigate the association between hypoxic-ischaemic insult timing and brain injury type in infants with severe cerebral palsy (CP).

DESIGN

Longitudinal study.

SETTING

Database of the Recurrence Prevention Committee, Japan Obstetric Compensation System for Cerebral Palsy.

SAMPLE

Infants with severe CP born at ≥34 weeks of gestation.

METHODS

The intrapartum fetal heart rate (FHR) strips were categorised as continuous bradycardia; persistently non-reassuring (NR-NR); reassuring-prolonged deceleration (R-PD); Hon's pattern (R-Hon); persistently reassuring (R-R); and unclassified. The brain magnetic resonance imaging (MRI) scans were categorised based on the predominant site involved: basal ganglia-thalamus (BGT); white matter (WM); watershed (WS); stroke; normal; and unclassified.

MAIN OUTCOME MEASURES

Manifestations of the brain MRI types and the association between FHR evolution pattern and MRI type were analysed.

RESULTS

Among 672 eligible infants, 76% had BGT-dominant injury, 5.4% WM, 1.2% WS, 1.6% stroke, 1.9% normal, and 14% unclassified. Placental abruption and small-for-gestational age were associated with an increased (adjusted odds ratio [aOR] 8.02) and decreased (aOR 0.38) risk of BGT injury, respectively. The majority of infants had BGT injury in most FHR groups (bradycardia, 97%; NR-NR, 75%; R-PD, 90%; R-Hon, 76%; and R-R, 45%). The risk profiles in case of BGT in the NR-NR group were similar to those in the R-PD and R-Hon groups.

CONCLUSION

BGT-dominant brain damage accounted for three-fourths of the cases of CP in term or near-term infants, even in prenatal onset cases. Hypoxic-ischaemic insult has a major impact on CP development during the antenatal period.

Fetal heart rate pattern in term or near-term cerebral palsy: a nationwide cohort study

BACKGROUND

It is crucial to interpret fetal heart rate patterns with a focus on the pattern evolution during labor to estimate the relationship between cerebral palsy and delivery. However, nationwide data are not available.

OBJECTIVE

The aim of our study was to demonstrate the features of fetal heart rate pattern evolution and estimate the timing of fetal brain injury during labor in cerebral palsy cases.

STUDY DESIGN

In this longitudinal study, 1069 consecutive intrapartum fetal heart rate strips from infants with severe cerebral palsy at or beyond 34 weeks of gestation, were analyzed. They were categorized as follows: (1) continuous bradycardia (Bradycardia), (2) persistently nonreassuring, (3) reassuring-prolonged deceleration, (4) Hon's pattern, and (5) persistently reassuring. The clinical factors underlying cerebral palsy in each group were assessed.

RESULTS

Hypoxic brain injury during labor (those in the reassuring-prolonged deceleration and Hon's pattern groups) accounted for 31.5% of severe cerebral palsy cases and at least 30% of those developed during the antenatal period. Of the 1069 cases, 7.86% were classified as continuous bradycardia (n=84), 21.7% as persistently nonreassuring (n=232), 15.6% as reassuring-prolonged deceleration (n=167), 15.9% as Hon's pattern (n=170), 19.8% as persistently reassuring (n=212), and 19.1% were unclassified (n=204). The overall interobserver agreement was moderate (kappa 0.59). Placental abruption was the most common cause (31.9%) of cerebral palsy, accounting for almost 90% of cases in the continuous bradycardia group (64 of 73). Among the cases in the Hon's pattern group (n=67), umbilical cord abnormalities were the most common clinical factor for cerebral palsy development (29.9%), followed by placental abruption (20.9%), and inappropriate operative vaginal delivery (13.4%).

CONCLUSION

Intrapartum hypoxic brain injury accounted for approximately 30% of severe cerebral palsy cases, whereas a substantial proportion of the cases were suspected to have either a prenatal or postnatal onset. Up to 16% of cerebral palsy cases may be preventable by placing a greater focus on the earlier changes seen in the Hon's fetal heart rate progression.

Getting an Early Start in Understanding Perinatal Asphyxia Impact on the Cardiovascular System

Perinatal asphyxia (PA) is a burdening pathology with high short-term mortality and severe long-term consequences. Its incidence, reaching as high as 10 cases per 1000 live births in the less developed countries, prompts the need for better awareness and prevention of cases at risk, together with management by easily applicable protocols. PA acts first and foremost on the nervous tissue, but also on the heart, by hypoxia and subsequent ischemia-reperfusion injury. Myocardial development at birth is still incomplete and cannot adequately respond to this aggression. Cardiac dysfunction, including low ventricular output, bradycardia, and pulmonary hypertension, complicates the already compromised circulatory status of the newborn with PA. Multiorgan and especially cardiovascular failure seem to play a crucial role in the secondary phase of hypoxic-ischemic encephalopathy (HIE) and its high mortality rate. Hypothermia is an acceptable solution for HIE, but there is a fragile equilibrium between therapeutic gain and cardiovascular instability. A profound understanding of the underlying mechanisms of the nervous and cardiovascular systems and a close collaboration between the bench and bedside specialists in these domains is compulsory. More resources need to be directed toward the prevention of PA and the consecutive decrease of cardiovascular dysfunction. Not much can be done in case of an unexpected acute event that produces PA, where recognition and prompt delivery are the key factors for a positive clinical result. However, the situation is different for high-risk pregnancies or circumstances that make the fetus more vulnerable to asphyxia. Improving the outcome in these cases is possible through careful monitoring, identifying the high-risk pregnancies, and the implementation of novel prenatal strategies. Also, apart from adequately supporting the heart through the acute episode, there is a need for protocols for long-term cardiovascular follow-up. This will increase our recognition of any lasting myocardial damage and will enhance our perspective on the real impact of PA. The goal of this article is to review data on the cardiovascular consequences of PA, in the context of an immature cardiovascular system, discuss the potential contribution of cardiovascular impairment on short and long-term outcomes, and propose further directions of research in this field.

Anesthetic management of abdominal radical trachelectomy for uterine cervical cancer during pregnancy

Abdominal radical trachelectomy has been identified as a surgical option for fertility preservation in cervical cancer patients, particularly in pregnant women who strongly desire to continue their pregnancy. Since this procedure requires operating in the uterus, the hardness of the uterus can affect the ease of surgery. Generally, sevoflurane is used for anesthesia in non-obstetric surgery for pregnant women because uterine relaxation is advantageous for uterine blood flow maintenance. However, the use of sevoflurane during radical trachelectomy has not been thoroughly evaluated. Here, we report on anesthesia use in three cases of abdominal radical trachelectomy during pregnancy. Propofol enabled maintenance of uterine tension while not significantly affecting fetal growth. It is important to consider maintenance of uterine tension and fetal circulation in anesthesia management. During the operation, we performed an ultrasound examination every 30 min to confirm fetal well-being. Although frequent fetal heart rate monitoring of the pre-viable fetus is not recommended, if fetal bradycardia is detected, sevoflurane may then be used to improve fetal circulation. Additionally, if the fetal heartbeat stops, a radical hysterectomy would then be required. Therefore, we consider that fetal heart rate monitoring during this procedure is necessary, and propofol is suitable as an anesthetic for this surgery during pregnancy.

Temporal trends in perinatal mortality and cerebral palsy: A regional population-based study in southern Japan

AIM

The prevalence of cerebral palsy (CP) has not decreased in developed countries over the past 30 years. We examined gestational age-specific trends in the prevalence of CP.

METHODS

This unselected, population-based study was conducted in Miyazaki prefecture, Japan (10,000 deliveries annually), where 102,999 deliveries were registered between 2001 and 2010. Of these, 312 were stillbirths (⩾22 weeks of gestation), 126 were neonatal deaths (<28 days of birth), and 214 infants were determined to be at risk of CP at peer-review conferences. Survival and neurological damage were compared for two 5-year periods, 2001-2005 and 2006-2010, and infants were classified according to gestational ages.

RESULTS

Stillbirths and neonatal deaths decreased significantly during both periods. Likewise, the number of registered high-risk cases of CP decreased by 30.2%, from 126 to 88 cases. After excluding congenital anomalies, the corrected CP prevalence was 1.5 per 1000 (78/51,889) and 1.3 per 1000 (67/51,110), for the two periods, which was not a significant difference. The number of extremely preterm infants (22-25 weeks) did not change over the 10-year period, whereas that of moderately preterm infants (26-36 weeks) increased, and that of term infants significantly decreased (p<0.01). In term infants, asphyxia decreased from 18 to 7 cases (p<0.05).

CONCLUSIONS

Perinatal deaths and CP decreased in prevalence during both 5-year periods, and the CP prevalence was 2.1 per 1000 births. Furthermore, fewer term infants were at high risk for CP mainly because of the reduced prevalence of asphyxia.

Intrapartum fetal heart rate patterns preceding terminal bradycardia in infants (>34 weeks) with poor neurological outcome: A regional population-based study in Japan

AIM

Intrapartum fetal bradycardia necessitates immediate operative delivery. Our aim was to investigate the hypothesis that some non-reassuring fetal heart rate (FHR) patterns were present before the onset of terminal bradycardia in infants who developed subsequent brain damage.

MATERIAL AND METHODS

From a population-based study of 65,197 deliveries, 190 stillbirths, 115 neonatal deaths, and 136 neurologically high-risk infants were registered by the Miyazaki Perinatal Conference. There were 15 cases of neurologically high-risk infants born at >34 weeks of gestation exhibiting intrapartum terminal bradycardia. Focusing on the brain-damaged infants, we retrospectively analyzed FHR patterns for at least 1 h prior to the bradycardia.

RESULTS

Brain damage (cerebral palsy [n = 11] and mental retardation [n = 2]) was diagnosed at 2 years old in 13 out of 15 neurologically high-risk infants. Two infants had bradycardia on admission. In the remaining 11 infants, FHR patterns were reassuring in six (55%) and non-reassuring in five (45%), including late decelerations (n = 4) and variable decelerations (n = 2). Clinically relevant factors in the non-reassuring group included intrauterine infection (n = 3), malpresentation with umbilical cord coiling (n = 1), and unknown causes (n = 1). Clinically relevant features in the reassuring group included cord prolapse (n = 1), vaginal breech delivery (n = 1), shoulder dystocia (n = 1), rupture of membranes (n = 1), and unknown causes (n = 2).

CONCLUSION

More than half of the brain-damaged infants born at >34 weeks of gestation who exhibited intrapartum terminal bradycardia had unremarkable FHR patterns before abrupt-onset bradycardia. For those with non-reassuring patterns preceding bradycardia, intrauterine infection was the major sentinel event.

Litigation related to intrapartum fetal surveillance

The role of intrapartum care including cardiotocography (CTG) monitoring in cases of perinatal neurological injury receives considerable debate in both clinical and medicolegal settings. The debate, however, has distracted attention from fundamental questions about the timing, mechanism, and preventability of perinatal injury. CTG tracings are used as a surrogate for asphyxia with the timing of intervention ("rescue") predicated on the presumed severity of asphyxia. Using CTG in this way has prevented intrapartum stillbirth, but it has not reduced the long-term injury in part, because, contrary to popular belief, the majority of intrapartum fetal injuries are unassociated with severe hypoxia or severe neonatal depression. This article describes the timing and mechanisms, including mechanical factors, of intrapartum perinatal injury and the benefit of using the CTG, not for the purpose of "rescue", but for identifying risk factors for fetal injury and keeping the fetus out of harm's way.

Severe fetal acidemia in cases of clinical chorioamnionitis in which the infant later developed cerebral palsy

Background

The umbilical arterial pH (UApH) in cases of clinically apparent chorioamnionitis (CAM) in which the infant later develop severe cerebral palsy (CP) has not yet been fully investigated. The objective of this study was to determine the UApH in CAM cases in which the infant later develop severe CP.

Methods

A review was conducted unti1 April 2014 among 324 infants with CP diagnosed to be caused by antenatal and/or intrapartum conditions, as determined by the Japan Council for Quality Health Care. Eighty-six infants born at over 34 weeks of gestation with an abnormal FHR pattern during labor were selected. The subjects were divided into the following two groups: cases with (Group I, n = 19) and those without (Group II, n = 67) clinical CAM. Severe fetal acidemia was defined as a pH of less than 7.0.

Results

The frequency of severe acidemia in Groups 1 and II was 26.3 and 74.6 %, respectively. In addition, the frequency of severe acidemia was significantly less in Group I (odds ratio (OR) 0.12, 95 % confidence interval (CI) 0.03–0.53) than in Group II, while the frequency of fetal tachycardia was greater in Group I (OR 7.61, 95 % CI 1.82–31.7) than in Group II, after adjusting for confounding effects.

Conclusions

The frequency of severe acidemia was lower in the cases of clinical CAM in which the infant later developed severe cerebral palsy than in the cases without clinical CAM. The relation of fetal tachycardia to CP with clinical CAM, but not to acidemia, should be reevaluated in such cases.

Umbilical arterial pH in patients with cerebral palsy

BACKGROUND

Umbilical arterial pH (UApH) in severe cerebral palsy (CP) is not fully understood.

AIMS

This work aims to determine the relationship between fetal acidemia and clinical features of severe CP.

STUDY DESIGN

A retrospective study design is used.

SUBJECTS

A review was conducted unti1 April 2013 among 218 infants with CP diagnosed to be caused by antenatal and/or intrapartum conditions determined by the Japan Council for Quality Health Care. After excluding patients in whom the causes of CP were thought to be due to events after delivery, 168 infants born at over 34weeks of gestation that both Apgar score and UApH were measured were selected.

OUTCOME MEASURES

Severe fetal acidemia was defined as a pH of less than 7.0.

RESULTS

Six major factors were found to be associated with CP: placental abruption (A, n=42), traumatic delivery with an abnormal FHR pattern (B, n=29), an abnormal FHR pattern during labor (C, n=27), chorioamnionitis with an abnormal FHR pattern (D, n=17), an abnormal FHR pattern before labor (E, n=14), and cord prolapse (F, n=10). The UApH was less than 7.0 in 114 cases (67.9%) and more than 7.20 in 20 cases (11.9%). The UApH values were lowest in group A (median 6.7, 6.43-6.99) and highest in group E (7.18, 6.92-7.45). The distribution of the UApH values was significantly different in these groups.

CONCLUSION

Placental abruption was a factor most associated with low pH. Even among the infants with severe CP, over 10% of patients exhibited a non-acidemic status at birth.

Perinatal death and neurological damage as a sequential chain of poor outcome

OBJECTIVE

We investigated the risk factors of perinatal death and neurological damage.

METHODS

Perinatal death and neurological damage were retrospectively investigated using a population-based study of 108 024 deliveries from 1998 to 2007. Main factors studied were asphyxia, growth restriction and preterm delivery < 34 weeks of gestation, since these three factors were most often associated with poor prognosis. The impact of each factor was identified by multiple regression analyses.

RESULTS

There were 459 perinatal deaths (4.3/1000) and 220 neurological damages (2.0/1000). Preterm delivery accounted for 50% of perinatal deaths and neurological damage, whereas it constituted 2.6% of total births. Multiple regression analyses showed that prematurity < 34 weeks (10-fold), asphyxia (10-fold) and growth restriction (2-fold) were independent and significant risk factors associated with poor outcomes, and that the magnitude was similar throughout the three consecutive critical events of fetal death, neonatal death and neurological damage.

CONCLUSIONS

Prematurity < 34 weeks, asphyxia and growth restriction are independent and persistent risk factors from perinatal death to neurological damage.

[Cerebral palsy and perinatal asphyxia (I--diagnosis)]

Cerebral palsy (CP) is a group of disorders of the development of movement and posture, causing activity limitations, that are attributed to nonprogressing disturbances that occurred in the developing fetal or infant brain. The motor abnormalies are often accompanied by disturbances of sensation, perception, cognition, behavior and/or by a seizure disorder. The prevalence of CP has not decreased in developed countries over the past 30 years, despite the widespread use of electronic fetal heart rate monitoring and a 5- to 6-fold increase in the cesarean delivery rate. In the term newborn, CP may be attributed to perinatal asphyxia in case of metabolic acidosis in the cord blood (pH<7,00 and base deficit>12 mmol/L), followed by a moderate or severe neonatal encephalopathy within 24 hours and a further neurological impairement characterized by spastic quadriplegia and dyskinesia/dystonia. Dating the time of fetal asphyxia during delivery is possible when there are acute catastrophic complications during labor and unexpected acute or progressive fetal heart rate anomalies after a normal admission test, when there is a need for intensive neonatal resuscitation, a multi-organ failure within 72 hours of birth and visualization of acute non focal cerebral abnormalities, mainly by early magnetic resonance imaging (MRI). MRI sequences show either a brain-damaged pattern of the central basal ganglia, thalami and posterior limbs of internal capsules with relative cortical sparing, in acute, near-total asphyxial insults manifested by a continuous bradycardia or a pattern of cortical injury in the watershed zones and relative sparing of the central grey matter, in prolonged partial asphyxia, manifested by late or atypical variable decelerations with progressive fetal tachycardia, loss of reactivity and absent fluctuation. Prolongation of either type of asphyxial insult results in more global brain damage. In order to differentiate a CP occurring after perinatal asphyxia from other neurological sequelae in relation with infection, hemorrhage, stroke, malformations, genetic or metabolic diseases, it is essential that a definitive information from the brain by MRI and an extensive histological examination of the placenta are at disposal.