Influence of maternal, obstetric and fetal risk factors on the prevalence of birth asphyxia at term in a Swedish urban population

Safety of and response to electroconvulsive therapy during pregnancy: Results from population-based nationwide registries

INTRODUCTION

Psychiatric disorders are common during pregnancy, affecting up to 16% of pregnant women. Severe depression and anxiety have significant negative effects on the health of both the mother and the developing fetus. Electroconvulsive therapy (ECT) is considered a treatment option for pregnant women with severe psychiatric disorders when other treatments have been ineffective or pose risks to the fetus. Knowledge of the safety and efficacy of ECT during pregnancy, however, remains limited.

METHODS

Data were obtained from nationwide registries of pregnant women in Sweden who received ECT for a severe psychiatric disorder from January 2008 to December 2021. ECT-related outcomes in pregnant women were compared by propensity score matching with a group of non-pregnant women who also received ECT. Pregnancy-related outcomes were compared with two additional control groups: one consisting of the same group of women who did not receive ECT during another pregnancy and the other composed of pregnant women admitted to inpatient psychiatric care but who did not receive ECT, matched based on propensity score.

RESULTS

Ninety-five pregnant women received ECT during the study period, accounting for 97 pregnancies. The response rate to ECT in pregnant women (n = 54) was similar to the matched control group of non-pregnant women (74% vs. 65%; OR 1.61; 95% CI 0.79-3.27). Rates of adverse events related to ECT were similar to those in the control group. There were no pre-term births or severe adverse outcomes related to the pregnancy, that were close in time to ECT. Therefore, no adverse outcomes related to pregnancy and childbirth could be directly attributed to ECT. The likelihood of premature birth and a 5-min Apgar score <7 in the newborn were both significantly higher in the ECT group, compared with the matched non-ECT group (OR 2.33, 95% CI 1.15-4.73, p = 0.008, and OR 3.68, 95% CI 1.58-8.55, p < 0.001, respectively). By contrast, no significant differences were observed when women in the pregnant ECT group were compared with the same group lacking ECT during another pregnancy.

CONCLUSIONS

ECT was associated with a positive treatment response in pregnant women with severe psychiatric disorders. The response rate to ECT was similar in pregnant and non-pregnant women. Nevertheless, the risks of premature birth and of a slightly poorer condition in newborns were higher in women who did than did not receive ECT, emphasizing the need for increased attention to severe psychiatric disorders during pregnancy.

A systematic catalog of studies on fetal heart rate pattern and neonatal outcome variables

OBJECTIVES

To study the methodology and results of studies assessing the relationship between fetal heart rate and specified neonatal outcomes including, heart rate, infection, necrotizing enterocolitis, intraventricular hemorrhage, hypoxic-ischemic encephalopathy, and seizure.

METHODS

Embase, Medline ALL, Web of Science Core Collection, Cochrane Central Register of Controlled Trials, and CINAHL were searched from inception to October 5, 2023.

RESULTS

Forty-two studies were included, encompassing 57,232 cases that underwent fetal monitoring and were evaluated for neonatal outcome. Heterogeneity was observed in the timing and duration of fetal heart rate assessment, classification guidelines used, number of assessors, and definition and timing of neonatal outcome assessment. Nonreassuring fetal heart rate was linked to lower neonatal heart rate variability. A significant increase in abnormal fetal heart rate patterns were reported in neonates with hypoxic-ischemic encephalopathy, but the predictive ability was found to be limited. Conflicting results were reported regarding sepsis, seizure and intraventricular hemorrhage. No association was found between necrotizing enterocolitis rate and fetal heart rate.

CONCLUSIONS

There is great heterogeneity in the methodology used in studies evaluating the association between fetal heart rate and aforementioned neonatal outcomes. Hypoxic-ischemic encephalopathy was associated with increased abnormal fetal heart rate patterns, although the predictive ability was low. Further research on developing and evaluating an automated early warning system that integrates computerized cardiotocography with a perinatal health parameter database to provide objective alerts for patients at-risk is recommended.

Temporalities of oxytocin for labour augmentation: a mixed-methods study of time factors shaping labour practices in a busy maternity unit in Tanzania

BACKGROUND

High rates of labour augmentation with oxytocin have been found in some low- and lower-middle-income countries, causing potential perinatal harm. It is critical to understand the reasons for this overuse. Aim was to explore factors that shape practices around using oxytocin for labour augmentation in a high-volume labour ward in Dar es Salaam, Tanzania.

METHODS

Mixed-methods data collection was conducted from March 2021 to February 2022, including structured observations of 234 births, 220 h of unstructured labour ward observations and 13 individual in-depth interviews with birth attendants. Thematic network analysis and descriptive statistics were used to analyse data. We used a time-lens to understand practices of oxytocin for labour augmentation in time-pressured labour wards.

RESULTS

Birth attendants constantly had to prioritise certain care practices over others in response to time pressure. This led to overuse of oxytocin for augmentation to ensure faster labour progression and decongestion of the, often overburdened, ward. Simultaneously, birth attendants had little time to monitor foetal and maternal condition. Surprisingly, while oxytocin was used in 146 out of 234 (62.4%) structured labour observations, only 9/234 (4.2%) women had active labour lasting more than 12 h. Correspondingly, 21/48 (43.8%) women who were augmented with oxytocin in the first stage of labour had uncomplicated labour progression at the start of augmentation. While the partograph was often not used for decision-making, timing of starting oxytocin often correlated with natural cycles of ward-rounds and shift-turnovers instead of individual women's labour progression. This resulted in co-existence of 'too early' and 'too late' use of oxytocin. Liberal use of oxytocin for labour augmentation was facilitated by an underlying fear of prolonged labour and low alertness of oxytocin-related risks.

CONCLUSIONS

Time scarcity in the labour ward often made birth attendants deviate from clinical guidelines for labour augmentation with oxytocin. Efforts to navigate time pressure resulted in too many women with uncomplicated labour progression receiving oxytocin with little monitoring of labour. Fear of prolonged labour and low alertness to oxytocin-mediated risks were crucial drivers. These findings call for research into safety and benefits of oxytocin in low-resource settings and interventions to address congestion in labour wards to prevent using oxytocin as a time-management tool.

Risk factors for neonatal hypoxic ischemic encephalopathy and therapeutic hypothermia: a matched case-control study

BACKGROUND

Peripartum asphyxia is one of the main causes of neonatal morbidity and mortality. In moderate and severe cases of asphyxia, a condition called hypoxic-ischemic encephalopathy (HIE) and associated permanent neurological morbidities may follow. Due to the multifactorial etiology of asphyxia, it may be difficult prevent, but in term neonates, therapeutic cooling can be used to prevent or reduce permanent brain damage. The aim of this study was to assess the significance of different antenatal and delivery related risk factors for moderate and severe HIE and the need for therapeutic hypothermia.

METHODS

We conducted a retrospective matched case-control study in Helsinki University area hospitals during 2013-2017. Newborn singletons with moderate or severe HIE and the need for therapeutic hypothermia were included. They were identified from the hospital database using ICD-codes P91.00, P91.01 and P91.02. For every newborn with the need for therapeutic hypothermia the consecutive term singleton newborn matched by gender, fetal presentation, delivery hospital, and the mode of delivery was selected as a control. Odds ratios (OR) between obstetric and delivery risk factors and the development of HIE were calculated.

RESULTS

Eighty-eight cases with matched controls met the inclusion criteria during the study period. Maternal and infant characteristics among cases and controls were similar, but smoking was more common among cases (aOR 1.46, CI 1.14-1.64, p = 0.003). The incidence of preeclampsia, diabetes and intrauterine growth restriction in groups was equal. Induction of labour (aOR 3.08, CI 1.18-8.05, p = 0.02) and obstetric emergencies (aOR 3.51, CI 1.28-9.60, p = 0.015) were more common in the case group. No difference was detected in the duration of the second stage of labour or the delivery analgesia.

CONCLUSIONS

Smoking, induction of labour and any obstetric emergency, especially shoulder dystocia, increase the risk for HIE and need for therapeutic hypothermia. The decisions upon induction of labour need to be carefully weighed, since maternal smoking and obstetric emergencies can hardly be controlled by the clinician.

The effect of intravenous hyoscine butylbromide on slow progress in labor (BUSCLAB): A double-blind randomized placebo-controlled trial

BACKGROUND

Prolonged labor is a common condition associated with maternal and perinatal complications. The standard treatment with oxytocin for augmentation of labor increases the risk of adverse outcomes. Hyoscine butylbromide is a spasmolytic drug with few side effects shown to shorten labor when used in a general population of laboring women. However, research on its effect on preventing prolonged labor is lacking. We aimed to assess the effect of hyoscine butylbromide on the duration of labor in nulliparous women showing early signs of slow labor.

METHODS AND FINDINGS

In this double-blind randomized placebo-controlled trial, we included 249 nulliparous women at term with 1 fetus in cephalic presentation and spontaneous start of labor, showing early signs of prolonged labor by crossing the alert line of the World Health Organization (WHO) partograph. The trial was conducted at Oslo University Hospital in Norway from May 2019 to December 2021. One hundred and twenty-five participants were randomized to receive 1 ml hyoscine butylbromide (Buscopan) (20 mg/ml), while 124 received 1 ml sodium chloride intravenously. Randomization was computer-generated, with allocation concealment by opaque sequentially numbered sealed envelopes. The primary outcome was duration of labor from administration of the investigational medicinal product (IMP) to vaginal delivery, which was analyzed by Weibull regression to estimate the cause-specific hazard ratio (HR) of vaginal delivery between the 2 treatment groups, with associated 95% confidence interval (CI). A wide range of secondary maternal and perinatal outcomes were also evaluated. Time-to-event outcomes were analyzed by Weibull regression, whereas continuous and dichotomous outcomes were analyzed by median regression and logistic regression, respectively. All main analyses were based on the modified intention-to-treat (ITT) set of eligible women with signed informed consent receiving either of the 2 treatments. The follow-up period lasted during the postpartum hospital stay. All personnel, participants, and researchers were blinded to the treatment allocation. Median (mean) labor duration from IMP administration to vaginal delivery was 401 (440.8) min in the hyoscine butylbromide group versus 432.5 (453.6) min in the placebo group. We found no statistically significant association between IMP and duration of labor from IMP administration to vaginal delivery: cause-specific HR of 1.00 (95% CI [0.77, 1.29]; p = 0.993). Among 255 randomized women having received 1 dose of IMP, 169 women (66.3%) reported a mild adverse event: 75.2% in the hyoscine butylbromide group and 57.1% in the placebo group (Pearson's chi-square test: p = 0.002). More than half of eligible women were not included in the study because they did not wish to participate or were not included upon admission. The participants might have represented a selected group of women reducing the external validity of the study.

CONCLUSIONS

One intravenous dose of 20 mg hyoscine butylbromide was not found to be superior to placebo in preventing slow labor progress in a population of first-time mothers at risk of prolonged labor. Further research is warranted to answer whether increased and/or repeated doses of hyoscine butylbromide might have an effect on duration of labor.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT03961165) EudraCT (2018-002338-19).

Sporadic accelerations during labor strongly indicate normal pH, whereas periodic accelerations do not: a case-control study

PURPOSE

To determine the association between the occurrence of sporadic and periodic fetal heart rate accelerations during labor and acidemia at birth.

MATERIALS AND METHODS

This is a case-control study of fetal heart rate patterns from 364 neonates with acidemia at birth (cord blood pH <7.05 at vaginal birth, or pH <7.10 at birth after first stage cesarean delivery) and 731 controls with pH ≥7.15. The last 30-60 min of the cardiotocographic traces before birth from the neonates born with acidemia and from the corresponding stage in labor for the controls were scrutinized. Odds ratios (OR) with 95% confidence interval for acidemia at birth were determined.

RESULTS

During the first stage, ≥2 sporadic accelerations were present in 16% of cases and 78% of controls; OR for acidemia (compared to 0-1 accelerations) 0.05 (0.02-0.10). In the second stage, the corresponding rates were 13% and 60%, OR 0.09 (0.06-0.14). Isolated periodic accelerations were infrequent. A weak negative association between ≥2 periodic accelerations and acidemia (compared with 0-1 accelerations) was found in the second stage, OR 0.51 (0.30-0.86), but was not significant in the first stage, OR 0.24 (0.04-1.4). Even among fetuses with normal fetal heart rate variability (5-25 beats per minute) the occurrence of less than two sporadic accelerations was associated with an increased risk of acidemia, OR 10.3 (7.2-14.8).

CONCLUSIONS

Sporadic accelerations indicate a very low probability of acidosis but are absent in 40% of fetuses with normal pH during a 30-60 min second-stage recording.

The impact of placental genomic risk for schizophrenia and birth asphyxia on brain development

The placenta plays a role in fetal brain development, and pregnancy and birth complications can be signs of placental dysfunction. Birth asphyxia is associated with smaller head size and higher risk of developing schizophrenia (SZ), but whether birth asphyxia and placental genomic risk factors associated with SZ are related and how they might impact brain development is unclear. 433 adult patients with SZ and 870 healthy controls were clinically evaluated and underwent brain magnetic resonance imaging. Pregnancy and birth information were obtained from the Medical Birth Registry of Norway. Polygenic risk scores (PRS) from the latest genome-wide association study in SZ were differentiated into placental PRS (PlacPRS) and non-placental PRS. If the interaction between PRSs and birth asphyxia on case-control status was significant, neonatal head circumference (nHC) and adult intracranial volume (ICV) were further evaluated with these variables using multiple regression. PlacPRS in individuals with a history of birth asphyxia was associated with a higher likelihood of being a patient with SZ (t = 2.10, p = 0.018). We found a significant interaction between PlacPRS and birth asphyxia on nHC in the whole sample (t = -2.43, p = 0.008), with higher placental PRS for SZ associated with lower nHC in those with birth asphyxia. This relationship was specific to males (t = -2.71, p = 0.005) and also found with their adult ICV (t = -1.97, p = 0.028). These findings suggest that placental pathophysiology and birth asphyxia may affect early and late trajectories of brain development, particularly in males with a higher vulnerability to SZ. This knowledge might lead to new strategies of treatment and prevention in SZ.

Low Apgar score and need for resuscitation increased the probability of receiving therapeutic hypothermia more strongly than acidosis at birth

AIM

The aim of this study was to investigate how individual markers for birth asphyxia, so-called A criteria, were associated with the probability of receiving therapeutic hypothermia.

METHODS

This population-based cohort study included 1336 live-born singleton term infants with any A criterion in the Stockholm-Gotland Region, Sweden during 2008 to 2014. The Swedish Neonatal Quality Register and National Patient Register were used for data collection. Results were presented as adjusted odds ratios (aORs) with 95% confidence intervals (CIs).

RESULTS

There were 89 infants, 44 boys and 45 girls with mean gestational age 40.5 weeks, who received therapeutic hypothermia. Low Apgar score, aOR 12.44 (95% CI 5.99-25.86), and resuscitation, aOR 9.18 (95% CI 3.77-22.34), were strongly associated with therapeutic hypothermia. A pH <7.0 was less associated with the outcome, aOR 2.02 (95% CI 1.02-4.0). No infant who received therapeutic hypothermia fulfilled the criteria of base deficit ≥16 mmol/L only.

CONCLUSION

A low Apgar score of and/or a need for resuscitation is more relevant for identifying infants eligible for therapeutic hypothermia, compared to other A criteria. This knowledge could be used clinically to identify cases for review and avoid unnecessary monitoring of infants.

Maternal and newborn plasma oxytocin levels in response to maternal synthetic oxytocin administration during labour, birth and postpartum - a systematic review with implications for the function of the oxytocinergic system

BACKGROUND

The reproductive hormone oxytocin facilitates labour, birth and postpartum adaptations for women and newborns. Synthetic oxytocin is commonly given to induce or augment labour and to decrease postpartum bleeding.

AIM

To systematically review studies measuring plasma oxytocin levels in women and newborns following maternal administration of synthetic oxytocin during labour, birth and/or postpartum and to consider possible impacts on endogenous oxytocin and related systems.

METHODS

Systematic searches of PubMed, CINAHL, PsycInfo and Scopus databases followed PRISMA guidelines, including all peer-reviewed studies in languages understood by the authors. Thirty-five publications met inclusion criteria, including 1373 women and 148 newborns. Studies varied substantially in design and methodology, so classical meta-analysis was not possible. Therefore, results were categorized, analysed and summarised in text and tables.

RESULTS

Infusions of synthetic oxytocin increased maternal plasma oxytocin levels dose-dependently; doubling the infusion rate approximately doubled oxytocin levels. Infusions below 10 milliunits per minute (mU/min) did not raise maternal oxytocin above the range observed in physiological labour. At high intrapartum infusion rates (up to 32 mU/min) maternal plasma oxytocin reached 2-3 times physiological levels. Postpartum synthetic oxytocin regimens used comparatively higher doses with shorter duration compared to labour, giving greater but transient maternal oxytocin elevations. Total postpartum dose was comparable to total intrapartum dose following vaginal birth, but post-caesarean dosages were higher. Newborn oxytocin levels were higher in the umbilical artery vs. umbilical vein, and both were higher than maternal plasma levels, implying substantial fetal oxytocin production in labour. Newborn oxytocin levels were not further elevated following maternal intrapartum synthetic oxytocin, suggesting that synthetic oxytocin at clinical doses does not cross from mother to fetus.

CONCLUSIONS

Synthetic oxytocin infusion during labour increased maternal plasma oxytocin levels 2-3-fold at the highest doses and was not associated with neonatal plasma oxytocin elevations. Therefore, direct effects from synthetic oxytocin transfer to maternal brain or fetus are unlikely. However, infusions of synthetic oxytocin in labour change uterine contraction patterns. This may influence uterine blood flow and maternal autonomic nervous system activity, potentially harming the fetus and increasing maternal pain and stress.

Study protocol for the BUSCopan in LABor (BUSCLAB) study: A randomized placebo-controlled trial investigating the effect of butylscopolamine bromide to prevent prolonged labor

Background

First-time mothers are prone to prolonged labor, defined as the crossing of partograph alert or action lines. Prolonged labor may occur among as many as one out of five women, and is associated with a range of adverse birth outcomes. Oxytocin is the standard treatment for prolonged labor, but has a narrow therapeutic window, several adverse effects and limited efficacy. Despite poor evidence, labor wards often use antispasmodic agents to treat prolonged labor. The antispasmodic drug butylscopolamine bromide (Buscopan^®) may shorten duration of labor, but studies on prevention of prolonged labor are lacking. In this randomized double-blind placebo-controlled clinical trial, we aim to evaluate the effect of butylscopolamine bromide on duration of labor in first-time mothers showing first signs of slow labor progress by crossing the World Health Organization partograph alert line.

Methods and analysis

The study is a single center study at Oslo University Hospital, Oslo, Norway. We will recruit 250 primiparous women with spontaneous labor start at term. Women are included in the first stage of labor if they show signs of slow labor progress, defined as the crossing of the partograph alert line with a cervical dilation between 3–9 cm. Participants are randomized 1:1 to either 20 mg intravenous butylscopolamine bromide or intravenous placebo (1 mL sodium chlorine 9 mg/mL). We considered a mean difference of 60 minutes in labor duration clinically relevant. The primary outcome is duration of labor from the provision of the investigational medicinal product to vaginal delivery. The secondary outcomes include change in labor pain, use of oxytocin augmentation, delivery mode, and maternal birth experience. The primary data for the statistical analysis will be the full analysis set and will occur on completion of the study as per the prespecified statistical analysis plan. The primary outcome will be analyzed using Weibull regression, and we will treat cesarean delivery as a censoring event.

Perinatal maternal characteristics predict a high risk of neonatal asphyxia: A multi-center retrospective cohort study in China

Objective

This study aimed to identify various perinatal maternal characteristics that contributed to neonatal asphyxia (NA) in term and late-preterm newborns based on the data obtained from a Chinese birth registry cohort and to establish an effective model for predicting a high risk of asphyxia.

Method

We retrospectively reviewed and analyzed the birth database from July 1, 2016, to June 30, 2017, in the main economically developed regions of China. Asphyxia was defined as an Apgar score <7 at 5 min post-delivery with umbilical cord arterial blood pH < 7.2 in the infant born after 34weeks. We compared the perinatal maternal characteristics of the newborns who developed asphyxia (NA group, n = 1,152) and those who did not (no NA group, n = 86,393). Candidate predictors of NA were analyzed using multivariable logistic regression. Subsequently, a prediction model was developed and validated by an independent test group.

Result

Of the maternal characteristics, duration of PROM ≥ 48 h, a gestational week at birth <37, prolonged duration of labor, hypertensive disorder, nuchal cord, and birth weight <2,500 or ≥4,000 g, abnormal fetal heart rate, meconium-stained amniotic fluid, and placenta previa were included in the predicting model, which presented a good performance in external validation (c-statistic of 0.731).

Conclusion

Our model relied heavily on clinical predictors that may be determined before or during birth, and pregnant women at high risk of NA might be recognized earlier in pregnancy and childbirth using this methodology, allowing them to avoid being neglected and delayed. Future studies should be conducted to assess its usefulness.

Risk factors for hypoxic-ischemic encephalopathy in cases of severe acidosis: A case-control study

INTRODUCTION

The aim of the study was to identify the obstetric risk factors for hypoxic-ischemic encephalopathy (HIE) in infants with asphyxia at birth.

MATERIAL AND METHODS

This multicenter case-control study covered the 5-year period from 2014 through 2018 and included newborns ≥36 weeks of gestation with an umbilical pH at birth ≤7.0. Cases were newborns who developed moderate or severe HIE; they were matched with controls with pH ≤7.0 at birth over the same period without moderate or severe HIE. The factors studied were maternal, gestational, intrapartum, delivery-related, and neonatal characteristics. A multivariable analysis was performed to study the maternal, obstetric, and neonatal factors independently associated with moderate or severe HIE.

RESULTS

Our review of the records identified 41 cases and 98 controls. Compared with controls, children with moderate or severe HIE had a lower 5-min Apgar score, lower umbilical artery pH, and higher cord lactate levels at birth and at 1 h of life. Obstetric factors associated with moderate or severe HIE were the occurrence of an acute event (adjusted odds ratio [aOR] 6.4; 95% confidence interval [CI] 1.8-22.5), maternal fever (aOR 3.5; 95% CI 1.0-11.9), and thick meconium during labor (aOR 2.9; 95% CI 1.0-8.6).

CONCLUSIONS

HIE is associated with a lower 5-min Apgar score and with the severity of acidosis at birth and at 1 h of life. In newborns with a pH <7.0 at birth, the occurrence of an acute obstetric event, maternal fever, and thick meconium are independent factors associated with moderate or severe HIE.

Pathophysiology of Perinatal Asphyxia in Humans and Animal Models

Perinatal asphyxia is caused by lack of oxygen delivery (hypoxia) to end organs due to an hypoxemic or ischemic insult occurring in temporal proximity to labor (peripartum) or delivery (intrapartum). Hypoxic-ischemic encephalopathy is the clinical manifestation of hypoxic injury to the brain and is usually graded as mild, moderate, or severe. The search for useful biomarkers to precisely predict the severity of lesions in perinatal asphyxia and hypoxic-ischemic encephalopathy (HIE) is a field of increasing interest. As pathophysiology is not fully comprehended, the gold standard for treatment remains an active area of research. Hypothermia has proven to be an effective neuroprotective strategy and has been implemented in clinical routine. Current studies are exploring various add-on therapies, including erythropoietin, xenon, topiramate, melatonin, and stem cells. This review aims to perform an updated integration of the pathophysiological processes after perinatal asphyxia in humans and animal models to allow us to answer some questions and provide an interim update on progress in this field.

How often will midwives and obstetricians experience obstetric emergencies or high-risk deliveries: a national cross-sectional study

OBJECTIVE

To estimate how often midwives, specialty trainees and doctors specialised in obstetrics and gynaecology are attending to specific obstetric emergencies or high-risk deliveries (obstetric events).

DESIGN

A national cross-sectional study.

SETTING

All hospital labour wards in Denmark.

PARTICIPANTS

Midwives (n=1303), specialty trainees (n=179) and doctors specialised in obstetrics and gynaecology (n=343) working in hospital labour wards (n=21) in Denmark in 2018.

METHODS

Categories of obstetric events comprised of Apgar score <7/5 min, eclampsia, emergency caesarean sections, severe postpartum haemorrhage, shoulder dystocia, umbilical cord prolapse, vaginal breech deliveries, vaginal twin deliveries and vacuum extraction. Data on number of healthcare professionals were obtained through the Danish maternity wards, the Danish Health Authority and the Danish Society of Obstetricians and Gynaecologists. We calculated the time interval between attending each obstetric event by dividing the number of events occurred with the number of healthcare professionals.

OUTCOME MEASURES

The time interval between attending a specific obstetric event.

RESULTS

The average time between experiencing obstetric events ranged from days to years. Emergency caesarean sections, which occur relatively frequent, were attended on average every other month by midwives, every 9 days for specialty trainees and every 17 days by specialist doctors. On average, rare events like eclampsia were experienced by midwives only every 42 years, every 6 years by specialty trainees and every 11 years by specialist doctors.

CONCLUSIONS

Some obstetric events occur extremely rarely, hindering the ability to obtain and maintain the clinical skills to manage them through clinical practice alone. By assessing the frequency of a healthcare professionals attending an obstetric emergency, our study contributes to assessing the need for supplementary educational initiatives and interventions to learn and maintain clinical skills.

Effect of intra-partum Oxytocin on neonatal encephalopathy: a systematic review and meta-analysis

Background

Oxytocin is widely used for induction and augmentation of labour, particularly in low- and middle-income countries (LMICs). In this systematic review and meta-analysis, we examined the effect of intra-partum Oxytocin use on neonatal encephalopathy.

Methods

The protocol for this study was registered with PROSPERO (ID: CRD42020165049). We searched Medline, Embase and Web of Science Core Collection databases for papers published between January 1970 and May 2021. We considered all studies involving term and near-term (≥36 weeks’ gestation) primigravidae and multiparous women. We included all randomised, quasi-randomised clinical trials, retrospective studies and non-randomised prospective studies reporting intra-partum Oxytocin administration for induction and/or augmentation of labour. Our primary outcome was neonatal encephalopathy. Risk of bias was assessed in non-randomised studies using the Risk Of Bias In Non-randomised Studies of Interventions (ROBINS-I) tool. The RoB 2.0 tool was used for randomised studies. A Mantel-Haenszel statistical method and random effects analysis model were used for meta-analysis. Odds ratios were used to determine effect measure and reported with 95% confidence intervals.

Results

We included data from seven studies (6 Case-control studies, 1 cluster-randomised trial) of which 3 took place in high-income countries (HICs) and 4 in LMICs. The pooled data included a total of 24,208 women giving birth at or after 36 weeks; 7642 had intra-partum Oxytocin for induction and/or augmentation of labour, and 16,566 did not receive intra-partum Oxytocin. Oxytocin use was associated with an increased prevalence of neonatal encephalopathy (Odds Ratio 2.19, 95% CI 1.58 to 3.04; p < 0.00001).

Conclusions

Intra-partum Oxytocin may increase the risk of neonatal encephalopathy. Future clinical trials of uterotonics should include neonatal encephalopathy as a key outcome.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-04216-3.

A Review on the Vagus Nerve and Autonomic Nervous System During Fetal Development: Searching for Critical Windows

The autonomic nervous system (ANS) is one of the main biological systems that regulates the body's physiology. Autonomic nervous system regulatory capacity begins before birth as the sympathetic and parasympathetic activity contributes significantly to the fetus' development. In particular, several studies have shown how vagus nerve is involved in many vital processes during fetal, perinatal, and postnatal life: from the regulation of inflammation through the anti-inflammatory cholinergic pathway, which may affect the functioning of each organ, to the production of hormones involved in bioenergetic metabolism. In addition, the vagus nerve has been recognized as the primary afferent pathway capable of transmitting information to the brain from every organ of the body. Therefore, this hypothesis paper aims to review the development of ANS during fetal and perinatal life, focusing particularly on the vagus nerve, to identify possible "critical windows" that could impact its maturation. These "critical windows" could help clinicians know when to monitor fetuses to effectively assess the developmental status of both ANS and specifically the vagus nerve. In addition, this paper will focus on which factors-i.e., fetal characteristics and behaviors, maternal lifestyle and pathologies, placental health and dysfunction, labor, incubator conditions, and drug exposure-may have an impact on the development of the vagus during the above-mentioned "critical window" and how. This analysis could help clinicians and stakeholders define precise guidelines for improving the management of fetuses and newborns, particularly to reduce the potential adverse environmental impacts on ANS development that may lead to persistent long-term consequences. Since the development of ANS and the vagus influence have been shown to be reflected in cardiac variability, this paper will rely in particular on studies using fetal heart rate variability (fHRV) to monitor the continued growth and health of both animal and human fetuses. In fact, fHRV is a non-invasive marker whose changes have been associated with ANS development, vagal modulation, systemic and neurological inflammatory reactions, and even fetal distress during labor.

A multicenter study of incidence, risk factors and outcomes of babies with birth asphyxia in Nepal

Background

Perinatal events which result in compromised oxygen delivery to the fetus can lead to Birth Asphyxia (BA). While the incidence, risk factors and outcomes of BA have been characterized, less is known in low resource settings.

Aim

To determine the incidence of Birth Asphyxia (BA) in Nepal and to evaluate associated risk factors and outcomes of this condition.

Methods

A nested observational study was conducted in 12 hospitals of Nepal for a period of 14 months. Babies diagnosed as BA at ≥37 weeks of gestation were identified and demographics were reviewed. Data were analyzed using binary logistic regression followed by multiple logistic regression analysis.

Results

The incidence of BA in this study was 6 per 1000 term livebirths and was higher among women 35 years and above. Predictors for BA were instrumented vaginal delivery (aOR:4.4, 95% CI, 3.1–6.1), fetal distress in labour (aOR:1.9, 95% CI, 1.0–3.6), malposition (aOR:1.8, 95% CI, 1.0–3.0), birth weight less than 2500 g (aOR:2.0, 95% CI, 1.3–2.9), gestational age ≥ 42 weeks (aOR:2.0, 95% CI, 1.3–3.3) and male gender (aOR:1.6, 95% CI, 1.2–2.0). The risk of pre-discharge mortality was 43 times higher in babies with BA (aOR:42.6, 95% CI, 32.2–56.3).

Conclusion

The incidence of Birth asphyxia in Nepal higher than in more resourced setting. A range of obstetric and neonatal risk factors are associated with BA with an associated high risk of pre-discharge mortality. Interventions to improve management and decrease rates of BA could have marked impact on outcomes in low resource settings.

Perinatal asphyxia from the obstetric standpoint

Perinatal asphyxia remains one of the major causes of morbidity and mortality for term newborns. Though access to health care and birth attendants have decreased the rate, Neonatal encephalopathy (NE) has not been eliminated. Worldwide, women at socioeconomic disadvantage have the highest risk of delivering a neonate with NE. Neonates that will experience perinatal asphyxia cannot be easily identified prospectively and the intrapartum testing available is not specific enough to clearly indicate the best course of action in most cases. Despite this, training programs that aim to decrease morbidity and mortality from all causes appear to be associated with fewer cases of perinatal asphyxia. The current best approach is to support education and communication for all people involved in the care of birthing women. Ideally, new technology will address identification of the fetus likely to be affected or the fetus who is beginning to experience injury in advance of delivery.

Biological and Psychosocial Factors, Risk Behaviors, and Perinatal Asphyxia in a University Hospital: Matched Case-Control Study, Cali, Colombia (2012-2014)

Introduction: Perinatal asphyxia is one of the main causes of morbidity and mortality in newborns. It generates high costs, both social and economic, and presents modifiable risk factors. Objective: To determine the biological and psychosocial factors and risk behaviors associated with the development of perinatal asphyxia (Sarnat II-III) in newborns from low socioeconomic status in a tier III university hospital in the city of Cali, Colombia. Materials and Methods: With a case and control design, 216 patients were studied (54 cases/162 controls) (1 case/3 matched controls). The cases were defined as newborns with modified or severe perinatal asphyxia (Sarnat II-III) between 2012 and 2014, with gestational age ≥ 36 weeks, with neurological signs not attributable to other causes, multiorgan compromise, advanced reanimation, and presence of a sentinel event. For the analysis, conditional logistic regression models were developed to evaluate association (OR), considering that the cases and controls had been paired by the birth and gestational age variables. Results: The final model showed that, from the group of biological variables, meconium amniotic fluid was identified as a risk factor (OR 15.28, 95%CI 2.78-83.94). Induction of labor lowered the risk of perinatal asphyxia by 97% (OR 0.03, 95%CI 0.01-0.21), and monitoring of fetal heart rate was associated with lower odds by 99% (OR 0.01, 95%CI 0.00-0.31) of developing perinatal asphyxia in the newborn. Regarding social variables, the lack of social support was identified as a risk factor for the development of perinatal asphyxia (OR 6.44, 95%CI 1.16-35.66); in contrast, secondary education lowered the odds of developing perinatal asphyxia by 85% when compared with pregnant women who only had primary school education (OR 0.15, 95%CI 0.03-0.77). Conclusion: Assessment of biological and psychosocial factors and social support is important in pregnant women to determine the risk of developing perinatal asphyxia in a low-income population.

Late Pregnancy Vitamin D Deficiency is Associated with Doubled Odds of Birth Asphyxia and Emergency Caesarean Section: A Prospective Cohort Study

Objectives

The aim of this prospective cohort study was to investigate the associations between maternal vitamin D status in late pregnancy and emergency caesarean section (EMCS) and birth asphyxia, in a population based sample of women in Sweden.

Methods

Pregnant women were recruited at the antenatal care in Sweden and 1832 women were included after exclusion of miscarriages, terminated pregnancies and missing data on vitamin D status. Mode of delivery was retrieved from medical records. EMCS was defined as caesarean section after onset of labour. Birth asphyxia was defined as either 5 min Apgar score < 7 or arterial umbilical cord pH < 7.1. Serum was sampled in the third trimester of pregnancy (T3) and 25-hydroxyvitamin D (25OHD) was analysed by liquid chromatography tandem mass spectrometry. Vitamin D deficiency was defined as 25OHD < 30 nmol/L, and associations were studied using logistic regression analysis and expressed as adjusted odds ratios (AOR).

Results

In total, 141 (7.7%) women had an EMCS and 58 (3.2%) children were born with birth asphyxia. Vitamin D deficiency was only associated with higher odds of EMCS in women without epidural anaesthesia (AOR = 2.01, p = 0.044). Vitamin D deficiency was also associated with higher odds of birth asphyxia (AOR = 2.22, p = 0.044).

Conclusions for Practice

In this Swedish prospective population-based cohort study, vitamin D deficiency in late pregnancy was associated with doubled odds of birth asphyxia and with EMCS in deliveries not aided by epidural anaesthesia. Prevention of vitamin D deficiency among pregnant women may reduce the incidence of EMCS and birth asphyxia. The mechanism behind the findings require further investigation.

Heart rate variability as possible marker of brain damage in neonates with hypoxic ischemic encephalopathy: a systematic review

Heart rate variability (HRV) is currently considered the most valuable non-invasive test to investigate the autonomic nervous system function, based on the fact that fast fluctuations might specifically reflect changes of sympathetic and vagal activity. An association between abnormal values of HRV and brain impairment has been reported in the perinatal period, although data are still fragmentary. Considering such association, HRV has been suggested as a possible marker of brain damage also in case of hypoxic-ischemic encephalopathy following perinatal asphyxia. The aim of the present manuscript was to review systematically the current knowledge about the use of HRV as marker of cerebral injury in neonates suffering from hypoxic-ischemic encephalopathy. Findings reported in this paper were based on qualitative analysis of the reviewed data. Conclusion: A growing body of research supports the use of HRV as non-invasive, bedside tool for the monitoring of hypoxic-ischemic encephalopathy. The currently available data about the role of HRV as prognostic tool in case of hypoxic ischemic encephalopathy are promising but require further validation by future studies. What is Known: • Heart rate variability (HRV) is a non-invasive monitoring technique to assess the autonomic nervous system activity. • A correlation between abnormal HRV and cerebral injury has been reported in the perinatal period, and HRV has been suggested as possible marker of brain damage in case of hypoxic-ischemic encephalopathy. What is New: • HRV might provide precocious information about the entity of brain injury in asphyxiated neonates and be of help to design early, specific, and personalized treatments according to severity. • Further investigations are required to confirm these preliminary data.

Prevalence and determinants of asphyxia neonatorum among live births at Debre Tabor General Hospital, North Central Ethiopia: a cross-sectional study

BACKGROUND

More than one third of the neonatal deaths at Neonatal Intensive Care Unit of Debre Tabor General Hospital (DTGH) are attributable to birth asphyxia. Most of these neonates are referred from maternity ward of the hospital. However, there is no recent evidence on the prevalence and specific determinants of birth asphyxia at DTGH. Besides, public health importance of factors like birth spacing weren't addressed in the prior studies.

METHODS

A cross sectional study was conducted on a sample of 240 newborns at delivery ward. The collected data were cleaned, coded and entered into Epi -data version 4.2 and exported to Stata version 14. Binary logistic regression model was considered and statistical significance was declared at P< 0.05 using adjusted odds ratio.

RESULTS

The prevalence of asphyxia neonatorum was 6.7 % based on the fifth minute APGAR score. From multi-variable logistic regression analysis, antenatal obstetric complications (AOR = 2.63, 95% CI: 3.75, 14.29), fetal malpresentation (AOR = 3.17, 95% CI: 1.21, 15.20), premature rupture of fetal membranes (AOR = 6.56, 95% CI: 3.48, 18.12) and meconium stained amniotic fluid (AOR = 2.73, 95% CI: 1.76, 14.59) were significant predictors.

CONCLUSION

The prevalence of fifth minute asphyxia neonatorum was relatively low. Fortunately, its predictors are modifiable. Thus, we can mitigate the problem even with our limited resources such as enhancing the existing efforts of antenatal and intra-partum care, which could help early detection and management of any obstetric and neonatal health abnormality."

Correlation between increased serum malondialdehyde and spectrum of cranial ultrasonography findings in hypoxic ischemic encephalopathy: could it be used as a predictor of disease severity?

Background

Hypoxic ischemic encephalopathy (HIE) is a major cause of mortality and morbidity in neonates. Malondialdehyde (MDH) is a colorless lipid that can be used as a marker for oxidative stress. Cranial ultrasound sensitivity and specificity in detection of neonatal HIE ought to be further investigated. This study aims to detect whether serum (MDH) can be used as an indicator for HIE severity and to assess the role of cranial ultrasound in diagnosis of HIE neurological disorders, correlating ultrasound findings to MDA levels.

Results

Statistically significant differences were found between the serum MDA levels in patients compared to controls as well as among serum MDA in patients with advancing Sarnat stages (I, II, III) P value < 0.001. Statistically significant levels of serum MDA were found in patients with ischemic US findings compared to those with normal scan; 36.4% of cases with ischemic US findings were diagnosed as Sarnat stage II while 63.6% were diagnosed with stage III with a statistically significant difference (P = 0.016).

Conclusion

Cranial ultrasound can be used for diagnosis of neonatal hypoxic ischemic insults, with lower sensitivity in mild cases and increased sensitivity in severe cases; and when combined with measuring serum MDA levels, it can be used as a diagnostic marker and as a predictor for severity of HIE.

Prevalence and associated factors of birth asphyxia among live births at Debre Tabor General Hospital, North Central Ethiopia

BACKGROUND

More than one third of the neonatal deaths at Neonatal Intensive Care Unit (NICU) in Debre Tabor General Hospital (DTGH) are attributable to birth asphyxia. Most of these neonates are referred from the maternity ward in the hospital. Concerns have also been raised regarding delayed intrapartum decisions for emergency obstetrics action in the hospital. However, there has been no recent scientific evidence about the exact burden of birth asphyxia and its specific determinants among live births at maternity ward of DTGH. Moreover, the public health importance of delivery time and professional mix of labor attendants haven't been addressed in the prior studies.

METHODS

Hospital based cross sectional study was conducted on a sample of 582 mother newborn dyads at maternity ward. Every other mother newborn dyad was included from December 2019 to March 2020. Pre-tested structured questionnaire and checklist were used for data collection. The collected data were processed and entered into Epidata version 4.2 and exported to Stata version 14. Binary logistic regressions were fitted and statistical significance was declared at p less than 0.05 with 95% CI.

RESULTS

The prevalence of birth asphyxia was 28.35% [95% CI: 26.51, 35.24%]. From the final model, fetal mal-presentation (AOR = 6.96: 3.16, 15.30), premature rupture of fetal membranes (AOR = 6.30, 95% CI: 2.45, 16.22), meconium stained amniotic fluid (AOR = 7.15: 3.07, 16.66), vacuum delivery (AOR =6.21: 2.62, 14.73), night time delivery (AOR = 6.01: 2.82, 12.79) and labor attendance by medical interns alone (AOR = 3.32:1.13, 9.78) were positively associated with birth asphyxia at 95% CI.

CONCLUSIONS

The prevalence of birth asphyxia has remained a problem of public health importance in the study setting. Therefore, the existing efforts of emergency obstetric and newborn care should be strengthened to prevent birth asphyxia from the complications of fetal mal-presentation, premature rupture of fetal membranes, meconium stained amniotic fluid and vacuum delivery. Moreover, night time deliveries and professional mixes of labor and/delivery care providers should be given more due emphasis.

A descriptive study of suspected perinatal asphyxia at Mitchells Plain District Hospital: A case series

Background

South Africa aims to end all preventable deaths of children under the age of five as part of their commitment to the Sustainable Development Goals. More than half of these mortalities occur in the neonatal period with perinatal asphyxia as one of the leading causes. This study investigated and identified the characteristics of perinatal asphyxia and its contributing factors at a district hospital in Cape Town.

Methods

A retrospective descriptive case series was performed and included all suspected cases of perinatal asphyxia referred from the Mitchells Plain District Hospital (MPH) to a specialised centre in the years 2016–2018. A data collection tool was used to extract information. Data were processed with Statistical Package for the Social Sciences 25 (SPSS) to produce descriptive statistics and to investigate associations between variables using the chi-square tests.

Results

The study included 29 cases of suspected perinatal asphyxia. Ten cases (34.5%) had abnormal amplitude electroencephalograms (aEEGs) indicative of hypoxic ischaemic encephalopathy (HIE) and four (13.8%) demised before day seven of life. Non-operative deliveries (p = 0.005), lack of a doctor at the time of delivery (p = 0.004) and neonatal chest compressions (p = 0.044) were associated with abnormal aEEGs. Babies with Thompson score of equal to or more than 12 (p = 0.006), neonatal seizures (p = 0.036) and delayed arrival at referral hospital (p = 0.005) were associated with abnormal aEEG findings. Mortality was associated with Thompson score equal to or more than 12 (p = 0.007) and the need for neonatal intubation at delivery (p = 0.016).

Conclusion

Significant reversible factors were identified in the peri- and post-partum periods. More capacitated staff would have the greatest impact on outcomes. The profile of HIE is exceedingly complex and challenges the resources and services of district level of care. Therefore, these factors should be targeted for future development and investment to improve outcomes from district hospitals.

Umbilical cord arterial blood gas analysis in term singleton pregnancies: a retrospective analysis over 11 years

Objective

Given that the large volume of data on cord arterial blood gas analysis (ABGA) have been rarely addressed in Korean population, we aimed to examine the incidence, associated factors, and neonatal outcomes in cases of low cord pH, and investigate the incidence of cerebral palsy (CP).

Methods

From data of all consecutive term singleton pregnancies delivered in our institution from 2006 to 2016 (n=15,701), cases with cord ABGA (n=14,221) available were included. We collected information on maternal clinical characteristics and delivery outcomes and also examined neonatal and infant outcomes, including neonatal intensive care unit (NICU) admission and CP, in cases with low cord pH, defined as a pH <7.1.

Results

Rates of low Apgar scores at 1 minute (<4) and 5 minutes (<7) were 0.6% (n=79) and 0.4% (n=58), respectively. Rates of cord pH <7.2, <7.1, and <7.0 were 7.1% (n=1,011), 1.1% (n=163), and 0.3% (n=38), respectively. Among cases with low cord pH, 30.1% (n=49/163) were admitted to the NICU and 11.0% (n=18/163) required ventilator support. Ultrasonography of the brain was performed in 28.8% (n=47/163), with abnormal findings observed in 27.7% (n=13/47). Among cases with low cord pH, 1.8% (n=3/163) were subsequently diagnosed with CP, including 2 cases of spastic CP and 1 of ataxic CP.

Conclusion

Although low cord pH was a relatively frequent finding observed in 1 out of every 87 cases, hypoxic-ischemic encephalopathy-related CP was found in only 1 out of 7,111 term singleton deliveries over 11 years in our institution.

Pre- and Perinatal Characteristics Associated with Apgar Scores in a Review and in a New Study of Dutch Twins

A literature review was carried out to identify pre and perinatal characteristics associated with variation in Apgar scores in population-based studies. The parameters identified in the literature search were included in the classical twin design study to estimate effects of pre and perinatal factors shared and nonshared by twins and to test for a contribution of genetic factors in 1- and 5-min Apgar scores in a large sample of Dutch monozygotic (MZ) and dizygotic (DZ) twins. The sample included MZ and DZ twins (N = 5181 pairs) recruited by the Netherlands Twin Register shortly after birth, with data on prenatal characteristics and Apgar scores at first and/or fifth minutes. The ordinal regression and structural equation modeling were used to analyze the effects of characteristics identified in the literature review and to estimate genetic and nongenetic variance components. The literature review identified 63 papers. Consistent with the review, we observed statistically significant effects of birth order, zygosity and gestational age (GA) for 1- and 5-min Apgar scores of both twins. Apgar scores are higher in first-born versus second-born twins and DZ first-born versus MZ first-born twins. Birth weight had an effect on the 5-min Apgar of the first born. Fetal presentation and mode of delivery had different effects on Apgar scores of first- and second-born twins. Parental characteristics and chorionicity did not have significant main effects on Apgar scores. The MZ twins' Apgar correlations equaled the DZ Apgar correlations. Our analyses suggest that individual differences in 1- and 5-min Apgar scores are attributable to shared and nonshared pre and perinatal factors, but not to genotypic factors of the newborns. The main predictors of Apgar scores are birth order, zygosity, GA, birth weight, mode of delivery and fetal presentation.

Association of perinatal risk factors with neurological outcome in neonates with hypoxic ischemic encephalopathy

OBJECTIVE

Neonates exposed to perinatal insults typically present with hypoxic ischemic encephalopathy (HIE). The aim of our study was to analyze the association between known risk factors for HIE and the severity of encephalopathy after birth and neurological outcome in neonates during the first 4 d of life.

METHODS

Retrospective cohort study including 174 neonates registered between 2011 and 2013 in the National Asphyxia and Cooling Register of Switzerland.

RESULTS

None of the studied perinatal risk factors is associated with the severity of encephalopathy after birth. Fetal distress during labor (OR, 2.06; 95% CI, 1.02-4.25, p = .049) and neonatal head circumference (HC) above 10th percentile (p10) at birth (OR, 1.33; 95% CI, 1.05-1.69, p = .02) were associated with neurological benefit in the univariate analysis. Fetal distress on maternal admission for delivery was the only risk factor for neurological harm in the univariate (OR, 0.26; 95% CI, 0.12-0.57, p < .01) and the multivariate analysis (OR, 0.15; 95% CI, 0.04-0.67, p = .013). We identified two different patient scenarios: the probability for neurological benefit during the first 4 d of life was only 20% in neonates with the combination of all the following risk factors (gestational age >41 weeks, chorioamnionitis, fetal distress on maternal admission for delivery, fetal distress during labor, sentinel events during labor, HC below 10th percentile), whereas in the absence of these risk factors the probability for neurological benefit increased to 80%.

CONCLUSIONS

We identified a constellation of risk factors that influence neurological outcome in neonates with HIE during the first 4 d of life. These findings may help clinicians to counsel parents during the early neonatal period. (ClinicalTrials.gov NCT02800018).

Factors associated with neonatal hypoxic ischemic encephalopathy in infants with an umbilical artery pH less than 7.00

OBJECTIVE

Our objective was to identify factors associated with hypoxic-ischemic encephalopathy (HIE) among newborns with an umbilical pH < 7.00.

STUDY DESIGN

Case-control study during a four-year study period in a single academic tertiary-center, including all neonates ≥35 weeks with an umbilical pH < 7.00. Cases were neonates with HIE, regardless of Sarnat classification, and controls were neonates without signs of HIE. We used univariate and multivariate analysis to compare the maternal, obstetric, and neonatal characteristics of cases and controls.

RESULTS

Among 21,211 births, 179 neonates≥35 weeks (0.84%) had an umbilical pH < 7.00. One hundred and forty-seven(82.1%) newborns had severe asphyxia without HIE, 32(17.9%) had HIE and 21(11.7%) needed therapeutic hypothermia. Neonates with HIE were significantly more likely to have 5-minute Apgar score<7(75% versus 15.7% P < 0.01), together with a lower mean umbilical arterial pH (6.84 versus 6.95, P < 0.01) and lower mean base deficits (-17.0 versus -12.7, P < 0.01). Factors significantly associated with HIE were the mother being overweight(28.1% for cases versus 14.3% for controls, adjusted OR=4.6[1.4-15.2]) or obese(25.0% versus 13.6%, aOR=15.5[1.1-12.5]), smoking(18.7% versus 5.4%, aOR=5.8[1.6-21.2]), a sentinel event as cord prolaps or placenta abruption (34.4% versus 13.6%, aOR=2.7[1.1-7.2]), and decreased fetal heart rate variability(68.7% versus 44.2%, aOR=2.8[1.1-6.9]).

CONCLUSION

Among neonates with an umbilical cord pH < 7.00, those with HIE had a more severe metabolic acidosis. Maternal factors associated with HIE among newborns with an umbilical pH < 7.00, were being overweight or obese, and smoking, and the associated obstetric factors were a sentinel event and decreased fetal heart rate variability.

Extracting Interesting Rules from Gestation Course Data for Early Diagnosis of Neonatal Hypoxia

The topic of neonatal hypoxia is of paramount importance to anyone who cares during pregnancy and childbirth. Modern medicine associates this pathology with severe problems in the prenatal period. Underlying diseases of the mother during pregnancy, her anamnesis of life are the leading causes of complications in the newborn. Nevertheless, patterns of fetal hypoxia and neonatal hypoxia, as well as mechanisms of hypoxic-ischemic encephalopathy in newborns, remains poorly known and require further research. This study is focused on finding risk factors related to the chronic fetal hypoxia and defining a group of signs for diagnosing neonatal hypoxia. The real data of 186 pregnant women at the gestation age from 12 to 38 weeks were analyzed. A methodology for discovering interesting associations in gestation course data is proposed. Technique for association rules mining and rules selection by the neonatal hypoxia under study is discussed. The rules suggest that a strong relationship exists between the specific sets of attributes and the diagnosis. As a result, we set up a profile of the pregnant woman with a high likelihood of hypoxia of the newborn that would be beneficial to medical professionals.

Determinants of birth asphyxia among live birth newborns in University of Gondar referral hospital, northwest Ethiopia: A case-control study

Background

Birth asphyxia, which accounts for 31.6% of all neonatal deaths, is one of the leading causes of such mortality in Ethiopia. Early recognition and management of its contributing factors would modify the problem. Thus, this study aimed to identify the determinants of birth asphyxia among live births at the University of Gondar Referral Hospital, northwest Ethiopia.

Methods

A hospital-based unmatched case-control study was conducted from April to July 2017.Cases were newborn babies with an APGAR score of < 7at 5 minutes of birth; controls were newborn babies with an APGAR score of ≥7 at 5 minutes of birth. Every other asphyxiated baby was selected as a case and every 6^th non-asphyxiated baby as a control. A pretested structured questionnaire was used to collect data on maternal sociodemographic characteristics. A pretested structured checklist was used to retrieve data on ante-partum, intra-partum, and neonatal factors of both cases and controls. Data were entered using Epi Info 7 and analyzed using SPSS 20. The bivariate logistic regression analysis was used to identify the relation of each independent variable to the outcome variable. Variables with p values of up to 0.2 in the bivariate analysis were considered for the multiple logistic regression analysis. An adjusted odds ratio (AOR) with a 95% CI and p-value of <0.05 was used to identify significant variables associated with birth asphyxia.

Results

In this study, prolonged labor (AOR = 2.75, 95% CI: 1.18, 6.94), cesarean section delivery (AOR = 3.58, 95% CI: 1.13, 11.31), meconium stained amniotic fluid (AOR = 7.69, 95% CI: 2.99, 17.70), fetal distress (AOR = 5.74, 95% CI: 1.53, 21.55), and low birth weight (AOR = 7.72, 95% CI: 1.88, 31.68) were factors which significantly increased the odds of birth asphyxia.

Conclusion

Prolonged labor, cesarean section (CS) delivery, meconium stained amniotic fluid (AF), fetal distress, and low birth weight were the determinants of birth asphyxia. Thus, efforts should be made to improve the quality of intra-partum care services in order to prevent prolonged labor and fetal complications, and to identify and make a strict follow up on mothers with meconium stained amniotic fluid.

LyTONEPAL: long term outcome of neonatal hypoxic encephalopathy in the era of neuroprotective treatment with hypothermia: a French population-based cohort

Background

Hypoxic-ischemic encephalopathy (HIE) is a rare neonatal condition affecting about 1‰ births. Despite a significant improvement in the management of this condition in the last ten years, HIE remains associated with high rates of death and severe neurological disability. From September 2015 to March 2017, a French national cohort of HIE cases was conducted to estimate the extent of long-term moderate and severe neurodevelopmental disability at 3 years and its determinants.

Methods

This prospective population-based cohort includes all moderate or severe cases of HIE, occurring in newborns delivered between 34 and 42 completed weeks of gestation and admitted to a neonatal intensive care unit. Detailed data on the pregnancy, delivery, and newborn until hospital discharge was collected from the medical records in maternity and neonatology units. All clinical examinations including biomarkers, EEG, and imaging were recorded. To ensure the completeness of HIE registration, a registry of non-included eligible neonates was organized, and the exhaustiveness of the cohort is currently checked using the national hospital discharge database. Follow-up is organized by the regional perinatal network, and 3 medical visits are planned at 18, 24 and 36 months. One additional project focused on early predictors, in particular early biomarkers, involves a quarter of the cohort.

Discussion

This cohort study aims to improve and update our knowledge about the incidence, the prognosis and the etiology of HIE, and to assess medical care. Its final objective is to improve the definition of this condition and develop prevention and management strategies for high-risk infants.

Trial registration

NCT02676063. Date of registration (Retrospectively Registered): February 8, 2016.

Intrapartum factors associated with neonatal hypoxic ischemic encephalopathy: a case-controlled study

BACKGROUND

Neonatal encephalopathy (NE) affects 2-4/1000 live births with outcomes ranging from negligible neurological deficits to severe neuromuscular dysfunction, cerebral palsy and death. Hypoxic ischemic encephalopathy (HIE) is the sub cohort of NE that appears to be driven by intrapartum events. Our objective was to identify antepartum and intrapartum factors associated with the development of neonatal HIE.

METHODS

Hospital databases were searched using relevant diagnosis codes to identify infants with neonatal encephalopathy. Cases were infants with encephalopathy and evidence of intrapartum hypoxia. For each hypoxic ischemic encephalopathy case, four controls were randomly selected from all deliveries that occurred within 6 months of the case.

RESULTS

Twenty-six cases met criteria for hypoxic ischemic encephalopathy between 2002 and 2014. In multivariate analysis, meconium-stained amniotic fluid (aOR 12.4, 95% CI 2.1-144.8, p = 0.002), prolonged second stage of labor (aOR 9.5, 95% CI 1.0-135.3, p = 0.042), and the occurrence of a sentinel or acute event (aOR 74.9, 95% CI 11.9-infinity, p < 0.001) were significantly associated with hypoxic ischemic encephalopathy. The presence of a category 3 fetal heart rate tracing in any of the four 15-min segments during the hour prior to delivery (28.0% versus 4.0%, p = 0.002) was more common among hypoxic ischemic encephalopathy cases.

CONCLUSION

Prolonged second stage of labor and the presence of meconium-stained amniotic fluid are risk factors for the development of HIE. Close scrutiny should be paid to labors that develop these features especially in the presence of an abnormal fetal heart tracing. Acute events also account for a substantial number of HIE cases and health systems should develop programs that can optimize the response to these emergencies.

Risk factors for intrapartum acidemia - a cohort study

PURPOSE

Birth acidemia is associated with short- and long-term morbidity in the child. Optimal intrapartum surveillance and timely interventions may reduce the incidence of these outcomes. Knowledge about conditions which increase the risks might be beneficial for optimal care. The aim with this study was to identify factors which increased the risk for lactacidemia in fetal scalp blood.

MATERIALS AND METHODS

A secondary analysis of a cohort study performed at Karolinska University Hospital Stockholm Sweden between February 2009 and February 2011. The study population included 1070 women in labor where fetal scalp blood sampling (FBS) was performed.

RESULTS

In a univariate logistic regression analysis for lactate >4.8 mmol/L at FBS, minor language barriers (OR 2.54; 95%CI 1.26-5.11), active bearing down (OR 2.46; 95%CI 1.12-5.39) and maternal height <155 cm (OR 2.15; 95%CI 1.08-4.26) were found as risk factors. In a multivariate logistic regression analysis, minor language barriers (OR 2.21; 95%CI 1.05-4.67) and active pushing (OR 2.68; 95%CI 1.20-6.00) remained significant.

CONCLUSIONS

Language barriers, active pushing and short stature were found to be significant risk factors for intrapartum lactacidemia. In the group with minor language problems better use of interpreters might be beneficial.

[Risk factors associated with the development of perinatal asphyxia in neonates at the Hospital Universitario del Valle, Cali, Colombia, 2010-2011]

INTRODUCTION

Perinatal asphyxia is one of the main causes of perinatal mortality and morbidity worldwide and it generates high costs for health systems; however, it has modifiable risk factors.

OBJECTIVE

To identify the risk factors associated with the development of perinatal asphyxia in newborns at Hospital Universitario del Valle, Cali, Colombia.

MATERIALS AND METHODS

Incident cases and concurrent controls were examined. Cases were defined as newborns with moderate to severe perinatal asphyxia who were older than or equal to 36 weeks of gestational age, needed advanced resuscitation and presented one of the following: early neurological disorders, multi-organ commitment or a sentinel event. The controls were newborns without asphyxia who were born one week apart from the case at the most and had a comparable gestational age. Patients with major congenital malformations and syndromes were excluded.

RESULTS

Fifty-six cases and 168 controls were examined. Premature placental abruption (OR=41.09; 95%CI: 4.61-366.56), labor with a prolonged expulsive phase (OR=31.76; 95%CI: 8.33-121.19), lack of oxytocin use (OR=2.57; 95% CI: 1.08 - 6.13) and mothers without a partner (OR=2.56; 95% CI: 1.21-5.41) were risk factors for the development of perinatal asphyxia in the study population. Social difficulties were found in a greater proportion among the mothers of cases.

CONCLUSIONS

Proper control and monitoring of labor, development of a thorough partograph, and active searches are recommended to ensure that all pregnant women have adequate prenatal care with the provision of social support to reduce the frequency and negative impact of perinatal asphyxia.

Risk factors and outcomes in "well-selected" vaginal breech deliveries: a retrospective observational study

OBJECTIVE

To assess risk factors for adverse perinatal and neonatal outcomes in "well-selected" singleton vaginal breech deliveries at term.

METHODS

During the time span from January 2008 up to April 2015 a total of 786 singleton term breech deliveries with a planned vaginal delivery were identified in a retrospective observational study at Helsinki University Central Hospital, Finland. The study's end point was a composite of adverse perinatal and neonatal outcomes. Infants with an adverse outcome were compared to all spontaneous singleton vaginal breech deliveries with normal perinatal and neonatal outcomes. A multivariate logistic regression model was used to analyze associations between adverse neonatal outcomes and several variables. The secondary outcome was the severe morbidity rate according to the criteria of the term breech trial.

RESULTS

An adverse neonatal outcome was recorded for 38 (4.8%) infants. According to the study the second delivery stage lasting <40 min [adjusted odds ratio (aOR): 0.34, 95% confidence interval (95% CI): 0.15-0.79] was associated with lower odds and had a protective effect against adverse outcomes. Epidural anesthesia (aOR: 2.88, 95% CI: 1.08-7.70) was associated with higher adverse outcomes. The incidence rate of severe morbidity was 1.3% (10/787).

CONCLUSION

Adverse neonatal outcomes in well-selected breech deliveries are associated with a prolonged second delivery stage lasting >40 min and with epidural anesthesia.

A policy of routine umbilical cord blood gas analysis decreased missing samples from high-risk births

AIM

This study compared obstetric units practicing routine or selective umbilical cord blood gas analysis, with respect to the risk of missing samples in high-risk deliveries and in infants with birth asphyxia.

METHODS

This was a Swedish population-based cohort study that used register data for 155 235 deliveries of live singleton infants between 2008 and 2014. Risk ratios and 95% confidence intervals were calculated to estimate the association between routine and selective umbilical cord blood gas sampling strategies and the risk of missing samples.

RESULTS

Selective sampling increased the risk ratios when routine sampling was used as the reference, with a value of 1.0, and these were significant in high-risk deliveries and birth asphyxia. The risk ratios for selective sampling were large-for-gestational age (9.07), preterm delivery at up to 36 weeks of gestation (8.24), small-for-gestational age (7.94), two or more foetal scalp blood samples (5.96), an Apgar score of less than seven at one minute (2.36), emergency Caesarean section (1.67) and instrumental vaginal delivery (1.24).

CONCLUSION

Compared with routine sampling, selective umbilical cord blood gas sampling significantly increased the risks of missing samples in high-risk deliveries and in infants with birth asphyxia.

Impact of Thrombophilia on the Risk of Hypoxic-Ischemic Encephalopathy in Term Neonates

BACKGROUND

The incidence of neonatal hypoxic-ischemic encephalopathy (HIE) is reportedly high in countries with limited resources. Its pathogenesis is multifactorial. A role for thrombophilia has been described in different patterns of preterm and full-term perinatal brain injury.

AIM

This study aims to identify risk factors associated with neonatal HIE and also to determine the contributions of genetic thrombophilia in the development of neonatal HIE.

METHODS

Sixty-seven neonates with HIE and 67 controls were enrolled in the study. Clinical history and examination were undertaken. Patients and controls were tested for the presence of factor V G1691A and prothrombin G20210A mutations. In addition, protein S, protein C, and antithrombin III levels were assessed.

RESULTS

Parental consanguinity and performing emergency cesarean section (CS) were significant risk factors for neonatal HIE (odds ratio [OR] 6.5, 95% confidence interval [CI] 2.6-15.3, P < .001, OR 12.6, 95% CI 2.52-63.3, P = .002, respectively). No significant difference was found regarding maternal age and parity. About 33% of cases and 6% of controls were found to have at least 1 thrombophilic factor ( P < .001). Factor V G1691A mutation significantly increased the risk of neonatal HIE (OR 4.5, 95% CI 1.4-14.5, P = .012), while prothrombin G 20210A mutation and protein C deficiency were not.

CONCLUSION

Parental consanguinity, emergency CS, and factor V mutation may contribute to the higher risk of developing neonatal HIE.

Clinical suspicion, management and outcome of intrapartum foetal distress in a public hospital with limited advanced foetal surveillance

OBJECTIVES

To determine the basis for the clinical suspicion of foetal distress, the instituted managements and delivery outcome in a tertiary hospital in sub-Saharan Africa with limited capability for advanced foetal monitoring.

METHODS

It is a 3-year retrospective analysis of all the obstetrics cases with intrapartum foetal distress.

RESULTS

There were 301 cases reviewed. The birth asphyxia incidence rate was 233/1000 live births and the perinatal death rate was 47/1000 live births. Suspicion of foetal distress was premised on the presence of persistent tachycardia or bradycardia during intermittent auscultation. Main resuscitative measures were left lateral repositioning of patient, fast saline infusion, intranasal oxygen administration and discontinuation of oxytocin infusion, if any. Only 124 (41.2%) of all the cases had delivery achieved within 2 h of diagnosis. Mean decision-delivery interval by caesarean section was 2.93 ± 2.05 h. Socio-demographic factors (p= 0.001) and pregnancy risk category (p = 0.002) influenced incidence of birth asphyxia.

CONCLUSION

To reduce subsisting high perinatal morbidity and mortality in sub-Saharan Africa, it is best that at the least referral hospitals should have advanced facilities for foetal monitoring and shortened surgical intervention time.

Preterm Birth: A Prominent Risk Factor for Low Apgar Scores

OBJECTIVE

To determine predictive risk factors for Apgar scores < 7 at 5 minutes at two hospitals providing tertiary care and secondary care, respectively.

METHODS

A retrospective registry cohort study of 21126 births (2006-2010) using data from digital medical records. Risk factors were analyzed by logistic regression analyses.

RESULTS

AS(5 min) < 7 was multivariately associated with the following: preterm birth; gestational week 32 + 0-36 + 6, OR = 3.9 (95% CI 2.9-5.3); week 28 + 0-31 + 6, OR = 8 (5-12); week < 28 + 0, OR = 15 (8-29); postterm birth, OR = 2.0 (1.7-2.3); multiple pregnancy, OR = 3.53 (1.79-6.96); previous cesarean section, OR = 3.67 (2.31-5.81); BMI 25-29, OR = 1.30 (1.09-1.55); BMI ≥ 30  OR = 1.70 (1.20-2.41); nonnormal CTG at admission, OR = 1.98 (1.48-2.66). ≥ 1-para was associated with a decreased risk for AS(5 min) < 7, OR = 0.34 (0.25-0.47). In the univariate logistic regression analysis AS(5 min) < 7 was associated with tertiary level care, OR = 1.48 (1.17-1.87); however, in the multivariate analysis there was no significant difference.

CONCLUSION

A number of partially preventable risk factors were identified, preterm birth being the most evident. Further, no significant difference between the two hospital levels regarding the risk for low Apgar scores was detected.

Perinatal asphyxia associated with early neonatal mortality: populational study of avoidable deaths

OBJECTIVE

To compare the epidemiological profile of avoidable early neonatal deaths associated with perinatal asphyxia according to region of death in the State of São Paulo, Brazil.

METHODS

Population-based cohort study including 2,873 avoidable deaths up to six days of life associated with perinatal asphyxia from January 2001 to December 2003. Perinatal asphyxia was considered if intrauterine hypoxia, birth asphyxia, or meconium aspiration syndrome were written in any line of the original Death Certificate. Epidemiological data were also extracted from the Birth Certificate.

RESULTS

During the three years, 1.71 deaths per 1,000 live births were associated with perinatal asphyxia, which corresponded to 22% of the early neonatal deaths. From the 2,873 avoidable deaths, 761 (27%) occurred in São Paulo city; 640 (22%), in the metropolitan region of São Paulo city; and 1,472 (51%), in the countryside of the state. In the first two regions, deaths were more frequent in public hospitals, among newborns with gestational age of 36 weeks or less, and among babies weighing less than 2500g. In the countryside, mortality was more frequent in philanthropic hospitals, in term newborns and in neonates weighing over 2500g. Most of these neonates were born during daytime in their hometown and died at the same institution in which they were born within the first 24 hours after delivery. Meconium aspiration syndrome was related to 18% of the deaths.

CONCLUSIONS

Perinatal asphyxia is a frequent contributor to the avoidable early neonatal death in the state with the highest gross domestic product per capita in Brazil, and it shows the need for specific interventions with regionalized focus during labor and birth care.

Perinatal risk factors for severe injury in neonates treated with whole-body hypothermia for encephalopathy

OBJECTIVE

Our objective was to identify perinatal risk factors that are available within 1 hour of birth that are associated with severe brain injury after hypothermia treatment for suspected hypoxic-ischemic encephalopathy.

STUDY DESIGN

One hundred nine neonates at ≥35 weeks' gestation who were admitted from January 2007 to September 2012 with suspected hypoxic-ischemic encephalopathy were treated with whole-body hypothermia; 98 of them (90%) underwent brain magnetic resonance imaging (MRI) at 7-10 days of life. Eight neonates died before brain imaging. Neonates who had severe brain injury, which was defined as death or abnormal MRI results (cases), were compared with surviving neonates with normal MRI (control subjects). Logistic regression models were used to identify risk factors that were predictive of severe injury.

RESULTS

Cases and control subjects did not differ with regard to gestational age, birthweight, mode of delivery, or diagnosis of nonreassuring fetal heart rate before delivery. Cases were significantly (P < .05) more likely to have had an abruption, a cord and neonatal arterial gas level that showed metabolic acidosis, lower platelet counts, lower glucose level, longer time to spontaneous respirations, intubation, chest compressions in the delivery room, and seizures. In multivariable logistic regression, lower initial neonatal arterial pH (P = .004), spontaneous respiration at >30 minutes of life (P = .002), and absence of exposure to oxytocin (P = .033) were associated independently with severe injury with 74.3% sensitivity and 74.4% specificity.

CONCLUSION

Worsening metabolic acidosis at birth, longer time to spontaneous respirations, and lack of exposure to oxytocin correlated with severe brain injury in neonates who were treated with whole-body hypothermia. These risk factors may help quickly identify neonatal candidates for time-sensitive investigational therapies for brain neuroprotection.

Impact of race on male predisposition to birth asphyxia

OBJECTIVE

To examine the associations of: (a) neonatal sex with mild-to-moderate and severe birth asphyxia, (b) fetal sex with mortality due to birth asphyxia and (c) neonatal race with severe birth asphyxia.

STUDY DESIGN

We used the Nationwide Inpatient Sample (NIS) Database including the years 1993 to 2008 or its pediatric sub portion Kid's Inpatient Database (KID) for the years 1997, 2000, 2003 and 2006. NIS database is collected annually from more than 1000 hospitals across the United States for millions of inpatient discharge summaries. We included newborns older than 36 weeks gestational age or more than 2500 g at birth. We excluded newborns with congenital heart disease, major congenital anomalies and chromosomal disorders. We compared birth asphyxia in males to females, and in each race compared with whites, and examined effect of sex in association with birth asphyxia within each race/ethnicity.

RESULT

There were 9 708 251 term infants (51.8% males) included in the study. There were 15 569 newborns diagnosed with severe birth asphyxia (1.6 in 1000); of them 56.1% were males. Odds ratio (OR)to have severe birth asphyxia in male newborns was 1.16 (confidence interval (CI): 1.12 to 1.20, P<0.001). Compared with Whites, African-American newborns had more birth asphyxia, OR 1.23 (CI: 1.16 to 1.31, P<0001), whereas Hispanics and Asians had less birth asphyxia. Native American newborns did not differ from their white counterparts. On comparing males to females within each race, male sex was associated with increased birth asphyxia in all races but Native American.

CONCLUSION

Male sex and African-American race were associated with increased prevalence of birth asphyxia.

Recurrence risk of low Apgar score among term singletons: a population-based cohort study

OBJECTIVE

To examine the risk of recurrence of low Apgar score in a subsequent term singleton pregnancy.

DESIGN

Population-based cohort study.

SETTING

The Netherlands.

POPULATION

A total of 190,725 women with two subsequent singleton term live births between 1999 and 2007.

METHODS

We calculated the recurrence risk of low Apgar score after adjustment for possible confounders. Women with an elective cesarean delivery, fetus in breech presentation or a fetus with congenital anomalies were excluded. Results were reported separately for women with a vaginal delivery or a cesarean delivery at first pregnancy.

MAIN OUTCOME MEASURES

Prevalence of birth asphyxia, a 5-min Apgar score <7.

RESULTS

The risk for an Apgar score of <7 in the first pregnancy was 0.99% and overall halved in the subsequent pregnancies (0.50%). For those with asphyxia in the first pregnancy, the risk of recurrence of a low Apgar score in the subsequent pregnancy was 1.1% (odds ratio 2.1, 95% confidence interval 1.4-3.3). This recurrence risk was present in women with a previous vaginal delivery (odds ratio 2.1, 95% confidence interval 1.2-3.5) and in women with a previous cesarean delivery (odds ratio 3.8, 95% confidence interval 1.7-8.5). Among women with a small-for-gestational-age infant in the subsequent pregnancy and a previous vaginal delivery, the recurrence risk was 4.8% (adjusted odds ratio 5.8, 95% confidence interval 2.0-16.5).

CONCLUSION

Women with birth asphyxia of the first born have twice the risk of renewed asphyxia at the next birth compared to women without birth asphyxia of the first born. This should be incorporated in the risk assessment of pregnant women.

Changes in cerebral oxygenation during early postnatal adaptation in newborns delivered by vacuum extraction measured by near-infrared spectroscopy

Background

Newborns delivered by vacuum extraction quite often show clinical signs of a hemodynamic compromise, which is difficult to assess in terms of severity. The conventional means to measure the hemodynamic status are not sensitive enough to appreciate the severity of general, and more specifically of cerebral circulatory imbalance. The aim was to study cerebral tissue oxygenation during postnatal adaptation in these infants using near-infrared spectroscopy.

Methods

The tissue hemoglobin index (THI), tissue oxygenation index (TOI), arterial oxygen saturation (pre-ductal SaO₂) and heart rate (HR) were recorded immediately after birth, and again after 12–24 hours of life in 15 newborns delivered by vacuum extraction due to fetal distress. A comparison with 19 healthy newborns delivered by elective cesarean section was performed.

Results

Newborns delivered by vacuum extraction had significantly higher THI 10 to 15 minutes after birth. TOI and HR were significantly higher in the first 5 min and SaO₂ in the first 10 minutes but then did not differ from those after cesarean section.

Conclusion

Infants delivered by vacuum extraction following fetal distress show transient deviations in cerebral oxygenation and perfusion after birth which were not detectable after 24 hours.

Antepartum and intrapartum factors preceding neonatal hypoxic-ischemic encephalopathy

OBJECTIVE

To determine whether antepartum factors alone, intrapartum factors alone, or both in combination, are associated with term neonatal hypoxic-ischemic encephalopathy (HIE).

METHODS

A total of 405 infants ≥ 35 weeks' gestation with early encephalopathy, born between 1992 and 2007, were compared with 239 neurologically normal infants born between 1996 and 1997. All cases met criteria for perinatal asphyxia, had neuroimaging findings consistent with acute hypoxia-ischemia, and had no evidence for a non-hypoxic-ischemic cause of their encephalopathy.

RESULTS

Both antepartum and intrapartum factors were associated with the development of HIE on univariate analysis. Case infants were more often delivered by emergency cesarean delivery (CD; 50% vs 11%, P < .001) and none was delivered by elective CD (vs 10% of controls). On logistic regression analysis only 1 antepartum factor (gestation ≥ 41 weeks) and 7 intrapartum factors (prolonged membrane rupture, abnormal cardiotocography, thick meconium, sentinel event, shoulder dystocia, tight nuchal cord, failed vacuum) remained independently associated with HIE (area under the curve 0.88; confidence interval 0.85-0.91; P < .001). Overall, 6.7% of cases and 43.5% of controls had only antepartum factors; 20% of cases and 5.8% of controls had only intrapartum factors; 69.5% of cases and 31% of controls had antepartum and intrapartum factors; and 3.7% of cases and 19.7% of controls had no identifiable risk factors (P < .001).

CONCLUSIONS

Our results do not support the hypothesis that HIE is attributable to antepartum factors alone, but they strongly point to the intrapartum period as the necessary factor in the development of this condition.

In utero exposure to ischemic-hypoxic conditions and attention-deficit/hyperactivity disorder

OBJECTIVE

To examine the association between ischemic-hypoxic conditions (IHCs) and attention-deficit/hyperactivity disorder (ADHD) by gestational age and race/ethnicity.

METHODS

Nested case-control study using the Kaiser Permanente Southern California (KPSC) medical records. The study cohort included children aged 5 to 11 years who were delivered and cared for in the KPSC between 1995 and 2010 (N = 308,634). Case children had a diagnosis of ADHD and received ≥ 2 prescriptions specific to ADHD during the follow-up period. For each case, 5 control children were matched by age at diagnosis. Exposures were defined by using International Classification of Diseases, Ninth Revision codes. A conditional regression model was used to estimate adjusted odds ratios (ORs).

RESULTS

Among eligible children, 13,613 (4.3%) had a diagnosis of ADHD. Compared with control children, case children were more likely to be male and of white or African American race/ethnicity. Case children were more likely to be exposed to IHCs (OR = 1.16, 95% confidence interval [CI] 1.11-1.21). When stratified by gestational age, cases born at 28 to 33, 34 to 36, and 37 to 42 weeks of gestation, were more likely to be exposed to IHCs (ORs, 1.6 [95% CI 1.2-2.1], 1.2 [95% CI 1.1-1.3], and 1.1 [95% CI 1.0-1.2], respectively) compared with controls. IHC was associated with increased odds of ADHD across all race/ethnicity groups.

CONCLUSIONS

These findings suggest that IHCs, especially birth asphyxia, respiratory distress syndrome, and preeclampsia, are independently associated with ADHD. This association was strongest in preterm births.