Association of Maternal Fever During Labor With Neonatal and Infant Morbidity and Mortality:

Prediction of meconium aspiration syndrome by data available before delivery

OBJECTIVE

To identify risk factors associated with the occurrence of meconium aspiration syndrome (MAS) among neonates.

METHODS

A retrospective case-control study in a university affiliated tertiary medical center, including all neonates born with meconium stained amniotic fluid (MSAF) between March 2011 and March 2020. Patients were categorized by the occurrence of MAS. Demographic, pregnancy and delivery characteristics were compared between the two groups. Risk factors for MAS were analyzed.

RESULTS

Of 90 579 singleton deliveries, a total of 11 856 with MSAF were included. Of these newborns, 78 (0.66%) were diagnosed with MAS Four factors were independently associated with MAS: delivery at <38 0/7 weeks (aOR [95% CI]: 3.48 (1.02-11.84), P = 0.046); higher body mass index (aOR [95% CI]: 1.09 (1.02-1.16), P = 0.003); lower amniotic fluid index (aOR [95% CI]: 0.99 (0.98-0.99), P = 0.032); higher white blood cell count (aOR [95% CI]: 1.11 (1.02-1.20), P = 0.009). The presence of one, two and three of the above-mentioned risk factors yielded a risk for MAS of 0.8%, 2.5% and 100%, respectively.

CONCLUSION

We identified independent risk factors for MAS and developed a risk score calculator. This tool may assist physicians in the management of deliveries complicated by MSAF.

Management of clinical chorioamnionitis: an evidence-based approach

This review aimed to examine the existing evidence about interventions proposed for the treatment of clinical chorioamnionitis, with the goal of developing an evidence-based contemporary approach for the management of this condition. Most trials that assessed the use of antibiotics in clinical chorioamnionitis included patients with a gestational age of ≥34 weeks and in labor. The first-line antimicrobial regimen for the treatment of clinical chorioamnionitis is ampicillin combined with gentamicin, which should be initiated during the intrapartum period. In the event of a cesarean delivery, patients should receive clindamycin at the time of umbilical cord clamping. The administration of additional antibiotic therapy does not appear to be necessary after vaginal or cesarean delivery. However, if postdelivery antibiotics are prescribed, there is support for the administration of an additional dose. Patients can receive antipyretic agents, mainly acetaminophen, even though there is no clear evidence of their benefits. Current evidence suggests that the administration of antenatal corticosteroids for fetal lung maturation and of magnesium sulfate for fetal neuroprotection to patients with clinical chorioamnionitis between 24 0/7 and 33 6/7 weeks of gestation, and possibly between 23 0/7 and 23 6/7 weeks of gestation, has an overall beneficial effect on the infant. However, delivery should not be delayed to complete the full course of corticosteroids and magnesium sulfate. Once the diagnosis of clinical chorioamnionitis has been established, delivery should be considered, regardless of the gestational age. Vaginal delivery is the safer option and cesarean delivery should be reserved for standard obstetrical indications. The time interval between the diagnosis of clinical chorioamnionitis and delivery is not related to most adverse maternal and neonatal outcomes. Patients may require a higher dose of oxytocin to achieve adequate uterine activity or greater uterine activity to effect a given change in cervical dilation. The benefit of using continuous electronic fetal heart rate monitoring in these patients is unclear. We identified the following promising interventions for the management of clinical chorioamnionitis: (1) an antibiotic regimen including ceftriaxone, clarithromycin, and metronidazole that provides coverage against the most commonly identified microorganisms in patients with clinical chorioamnionitis; (2) vaginal cleansing with antiseptic solutions before cesarean delivery with the aim of decreasing the risk of endometritis and, possibly, postoperative wound infection; and (3) antenatal administration of N-acetylcysteine, an antioxidant and antiinflammatory agent, to reduce neonatal morbidity and mortality. Well-powered randomized controlled trials are needed to assess these interventions in patients with clinical chorioamnionitis.

Epidural analgesia, intrapartum hyperthermia, and neonatal brain injury: a systematic review and meta-analysis

BACKGROUND

Epidural analgesia is associated with intrapartum hyperthermia, and chorioamnionitis is associated with neonatal brain injury. However, it is not known if epidural hyperthermia is associated with neonatal brain injury. This systematic review and meta-analysis investigated three questions: (1) does epidural analgesia cause intrapartum hyperthermia, (2) is intrapartum hyperthermia associated with neonatal brain injury, and (3) is epidural-induced hyperthermia associated with neonatal brain injury?

METHODS

PubMed, ISI Web of Knowledge, The Cochrane Library, and Embase were searched from inception to January 2020 using Medical Subject Headings (MeSH) terms relating to epidural analgesia, hyperthermia, labour, and neonatal brain injury. Studies were reviewed independently for inclusion and quality by two authors (Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach). Two meta-analyses were performed using the Mantel-Haenszel fixed effect method to generate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Forty-one studies were included for Question 1 (646 296 participants), 36 for Question 2 (11 866 021 participants), and two studies for Question 3 (297 113 participants). When the mode of analgesia was randomised, epidural analgesia was associated with intrapartum hyperthermia (OR: 4.21; 95% CI: 3.48-5.09). There was an association between intrapartum hyperthermia and neonatal brain injury (OR: 2.79; 95% CI: 2.54-2.3.06). It was not possible to quantify the association between epidural-induced hyperthermia and neonatal brain injury.

CONCLUSIONS

Epidural analgesia is a cause of intrapartum hyperthermia, and intrapartum hyperthermia of any cause is associated with neonatal brain injury. Further work is required to establish if epidural-induced hyperthermia is a cause of neonatal brain injury.

Neonatal Seizures Among Low-Risk Pregnancies at Term: Risk Factors and Adverse Outcomes

OBJECTIVE

To examine risk factors and adverse outcomes for neonatal-maternal dyads among low-risk pregnancies at term with subsequent neonatal seizures.

METHODS

United States vital statistics data sets were used for this retrospective study. Inclusion criteria were low-risk women (without hypertensive disease or diabetes) with nonanomalous singleton pregnancies, who delivered after labor at 37-41 weeks of gestation. The primary composite neonatal adverse outcome included 5-minute Apgar score less than 5, assisted ventilation longer than 6 hours, and neonatal death. A secondary outcome was composite maternal adverse outcome. Multivariable Poisson regression models with robust error variance were used, with adjusted relative risk (aRR) and 95% CI reported.

RESULTS

Of 19.76 million live births during the study interval, 11.7 million (59.4%) met inclusion criteria. The rate of neonatal seizures after low-risk pregnancies delivered at term was 0.2 per 1,000 live births. The maternal risks factors associated with neonatal seizures included no prenatal care, smoking during pregnancy, being overweight or obese, and gestational age of 41 weeks. The strongest risk factors for neonatal seizures were chorioamnionitis (relative risk [RR] 5.04, 95% CI 4.40-5.77; aRR 3.27, 95% CI 2.84-3.76) and route of delivery, with operative vaginal (RR 3.62, 95% CI 3.20-4.09; aRR 3.02, 95% CI 2.66-3.43) and cesarean (RR 4.13, 95% CI 3.81-4.48; aRR 3.14, 95% CI 2.86-3.45) higher than spontaneous vaginal. Compared with neonates without seizures, those with seizures had higher risk of composite neonatal adverse outcome (RR 64.55, 95% CI 61.83-67.39; aRR 37.09, 95% CI 35.20-39.08). Compared with women who delivered neonates without seizures, those who delivered neonates with seizures had higher risk of composite maternal adverse outcome (RR 16.27, 95% CI 13.66-19.37; aRR 9.70, 95% CI 8.15-11.53).

CONCLUSION

We identified modifiable maternal risk factors associated with neonatal seizures among low-risk pregnancies at term. Though infrequent, neonatal seizures are associated with higher risk of adverse outcomes in neonatal-maternal dyads.

Efficacy of "optimal hydration" during labor: HYDRATA study protocol for a randomized clinical trial

There is a lack of consensus in the international scientific community with respect to the most suitable hydration strategies when attending nulliparous women during low-risk births. This paper describes the protocol for a randomized controlled trial to compare two hydration strategies and their influence on maternal and neonatal morbidity. The study population consists of nulliparous women admitted to the obstetrics department of a University Hospital. The women are being randomized into two groups: the "optimal hydration" group, which will be guaranteed 300 ml/hr liquids (crystalloids and bottled mineral water) with a minimum diuresis of 35 ml/hr; and the "variability in hydration" group, which will receive intravenous (alternating normal saline, Ringer's lactate solution, glucose, or Voluven®) and clear (bottled mineral water or isotonic drinks [Aquarius®]) liquids, without any established perfusion rate, and without established minimum diuresis. Outcomes for mothers include duration of labor, cesarean section, fever, and dehydration. Outcomes for newborns are respiratory distress, hypoglycemia, hyponatremia, jaundice, weight loss over 48 hr, and breastfeeding difficulties. Analysis will be per-protocol. Administering optimal hydration may improve health and safety for mothers and their newborn and reduce maternal and neonatal morbidity. The study is registered at www.clinicaltrials.gov. The project received funding by the Ministry of Health of Spain and is approved by the Research Ethics Committee.

Singapore Neonatal Resuscitation Guidelines 2016

We present the revised Neonatal Resuscitation Guidelines for Singapore. The 2015 International Liaison Committee on Resuscitation Neonatal Task Force's consensus on science and treatment recommendations (2015), and guidelines from the American Heart Association and European Resuscitation Council were debated and discussed. The final recommendations of the National Resuscitation Council, Singapore, were derived after the task force had carefully reviewed the current available evidence in the literature and addressed their relevance to local clinical practice.

Fever and sickness behavior: Friend or foe?

Fever has been recognized as an important symptom of disease since ancient times. For many years, fever was treated as a putative life-threatening phenomenon. More recently, it has been recognized as an important part of the body's defense mechanisms; indeed at times it has even been used as a therapeutic agent. The knowledge of the functional role of the central nervous system in the genesis of fever has greatly improved over the last decade. It is clear that the febrile process, which develops in the sick individual, is just one of many brain-controlled sickness symptoms. Not only will the sick individual appear "feverish" but they may also display a range of behavioral changes, such as anorexia, fatigue, loss of interest in usual daily activities, social withdrawal, listlessness or malaise, hyperalgesia, sleep disturbances and cognitive dysfunction, collectively termed "sickness behavior". In this review we consider the issue of whether fever and sickness behaviors are friend or foe during: a critical illness, the common cold or influenza, in pregnancy and in the newborn. Deciding whether these sickness responses are beneficial or harmful will very much shape our approach to the use of antipyretics during illness.

Risk score comprising maternal and obstetric factors to identify late preterm infants at risk for neonatal intensive care unit admission

AIM

The aim of this study was to develop and validate an antepartum risk score based on maternal and obstetric characteristics to predict the requirement for neonatal intensive care unit (NICU) admission among late preterm infants.

MATERIAL AND METHODS

A chart review was performed of 455 singleton late preterm deliveries at our institution between July 2010 and December 2011. Logistic regression analysis was used to develop a risk score, which was derived from β coefficients of the significant variables. A receiver-operator curve was plotted to determine the optimal cut-off score for predicting NICU admission. Validation of the score was tested in another cohort of 450 women who delivered a singleton late preterm infant between January 2012 and June 2013.

RESULTS

A total of 98 infants (21.5%) in the development cohort were admitted to the NICU. The significant factors for NICU admission included: premature rupture of membranes, antepartum hemorrhage, medical disorders during pregnancy, prenatal estimation of fetal weight, gestational age at delivery, and mode of delivery. These six variables were integrated into a risk-scoring model, which ranged from -2 to 9 points. A cut-off score of ≥1 produced the maximum area under the receiver-operator curve of 0.764. At this cut-off point, the sensitivity was 79.6% and specificity was 73.1%. When the risk score was tested in the validation cohort, similar results were demonstrated.

CONCLUSION

An antepartum risk score was developed to predict the requirement for NICU admission among late preterm infants and was validated in an independent cohort.

Chorioamnionitis: epidemiology of newborn management and outcome United States 2008

OBJECTIVE

Current American Academy of Pediatric recommendations call for the empirical use of antibiotics for all well-appearing term newborn infants born to women given a diagnosis of chorioamnionitis. The objective of this analysis was to determine among term infants (37-42 weeks gestation) the prevalence of exposure to clinical chorioamnionitis, intrapartum antibiotics, infant antibiotic use and neonatal intensive care unit (NICU) admission and the relationship of these risk factors to neonatal mortality.

STUDY DESIGN

United States-linked infant birth and death certificate files for the year 2008 were used. Maternal demographic variables, labor and delivery risk factors and infant characteristics were analyzed for associations with a reported diagnosis of chorioamnionitis and neonatal death, NICU admission and antibiotic usage.

RESULT

There were 2,281,386 births available with information on the diagnosis of chorioamnionitis. The prevalence of chorioamnionitis in this population was 9.7 per 1000 live births (LB) and the neonatal mortality rate for exposed infants was 1.40/1000 LB vs 0.81/1000 LB for infants without chorioamnionitis, odds ratio (OR)=1.72, 95% confidence interval 1.20-2.45. The OR for neonatal death for infants with chorioamnionitis exposure who received antibiotics vs those who did not was 0.69 (95% confidence interval=0.21-2.26).

CONCLUSION

Exposure to chorioamnionitis is associated with an increased risk of neonatal mortality. Guidelines for treatment of infants exposed to chorioamnionitis with antibiotics are followed in only a small proportion of such cases.

Number of cervical examinations and risk of intrapartum maternal fever

OBJECTIVE

To estimate the association between number of cervical examinations and risk of maternal fever during term labor and delivery.

METHODS

Within a 4-year retrospective cohort study of all consecutive term (37 weeks of gestation or more) singleton deliveries reaching the second stage of labor, we identified women who developed an intrapartum fever and compared them with women who remained afebrile through 6 hours postpartum. Primary exposure was number of digital cervical examinations. Extensive data were collected from the medical record, including obstetric and medical history, cervical examinations and timing, admitting diagnoses, and outcomes. Time-to-event analyses were used to account for length of labor. Cox proportional hazard models were developed adjusting for potentially confounding factors.

RESULTS

Of 2,395 women who were afebrile at admission, 174 (7.2%) developed an intrapartum fever. Women were examined one to 14 times. There was no significant association between increasing number of examinations and risk of fever. Even for the 505 women who had more than seven examinations during labor, there was no statistically significant increased risk of fever (hazard ratio 0.9, 95% confidence interval 0.4-2.0) compared with those with one to three examinations. Subanalyses by labor type and examinations after rupture of membranes also showed no significant association between number of cervical examinations and risk of intrapartum fever.

CONCLUSION

During term labor management, maternal fever risk is not significantly increased by the number of cervical examinations.

LEVEL OF EVIDENCE

II.

Pandemic influenza and pregnant women: summary of a meeting of experts

Pandemic Influenza: Special Considerations for Pregnant Women was a meeting convened by the Centers for Disease Control and Prevention in 2008 to obtain input from experts and key partners regarding clinical management of pregnant women and related public health actions to be taken during a pandemic. Meeting goals were to discuss issues specific to pregnant women, identify gaps in knowledge, and develop a public health approach for pregnant women in the event of a pandemic. The meeting focused on 4 main topics: prophylaxis and treatment with influenza antiviral and other medications, vaccine use, nonpharmaceutical interventions and health care planning, and communications. Participants reviewed the available evidence to guide action in each of these areas and identified areas of critical needs for future research.

Intrapartum fever and chorioamnionitis as risks for encephalopathy in term newborns: a case-control study

In this study we examined the relationship between diagnoses of isolated intrapartum fever or chorioamnionitis and the risk of encephalopathy in term newborns. We conducted a population-based, case-control study in Washington State using 1994 to 2002 linked data from the Washington State Birth Registry and the Comprehensive Hospital Abstract Reporting System (CHARS). We identified 1060 singleton, term newborns (602 males, 458 females) with International Classification of Diseases (ICD-9) diagnoses consistent with encephalopathy, and 5330 unaffected control newborns (2756 males, 2574 females). Intrapartum fever was defined by a diagnosis of intrapartum temperature of >38 degrees C in the birth registry or CHARS databases. Chorioamnionitis was defined using ICD-9 diagnoses recorded in CHARS. We identified 2.2 cases of encephalopathy per 1000 births. Isolated intrapartum fever was associated with a 3.1-fold (95% confidence interval [CI] 2.3-4.2) increased risk of newborn encephalopathy. Chorioamnionitis was associated with a 5.4-fold (95% CI 3.6-7.8) increased risk of encephalopathy. We found that isolated intrapartum fever and chorioamnionitis were independently associated with an increased risk of encephalopathy in term infants. Our data also indicate that there is a spectrum of risk for encephalopathy in term infants exposed to intrapartum fever. Infants born to women with signs of chorioamnionitis other than isolated intrapartum fever may be at higher risk of encephalopathy than those exposed only to isolated intrapartum fever.

Approach to term neonates born after maternal intrapartum fever and unknown maternal group B Streptococcus status: value of serum C-reactive protein and 16S rRNA gene PCR amplification

Thirty-six term neonates born after maternal intrapartum fever, with premature rupture of membranes <18 hours and unknown maternal group B Streptococcus status had blood samples for complete blood count, C-reactive protein, culture, and 16S rRNA gene polymerase chain reaction amplification. Only 2 neonates were symptomatic and none had leukopenia, C-reactive protein >1.0 mg/dL, bacteremia, or positive polymerase chain reaction.

Depression at birth in term infants exposed to maternal chorioamnionitis: does neonatal fever play a role?

OBJECTIVES

(1) To determine the incidence and the time course of elevated temperature following delivery in term infants with clinical chorioamnionitis (CHORIO) and (2) to determine if the extent of temperature elevation at birth is associated with increased likelihood of NICU Admissions, birth depression, or with short-term neurological abnormalities.

DESIGN/METHODS

The infants were divided into two groups based on the median admission rectal temperature of 37.8 degrees C for the cohort. Depression at birth was defined as either the need of positive pressure ventilation for >2 minutes, intubation, or Apgar score <6 at 5 minutes. Neurological examination and assessment of encephalopathy (Sarnat staging) was performed at birth and daily thereafter, by one investigator blinded to temperature findings.

RESULTS

Infants with higher rectal temperature at 30 minutes of life were more likely to be admitted to NICU: OR (2.8, 95% confidence interval (CI) [1.8 to 4.3]), and were more likely to have birth depression OR (3, 95% CI [1.4 to 6.5]). For infants in NICU, a rectal temperature above 37.8 degrees C was present in 87% in the delivery room, persisted in 47% at 30 minutes, and declined to a normal temperature at 60 minutes of life in the absence of medical interventions. There was no relationship between neurological scores and neonatal temperature.

CONCLUSIONS

Term infants exposed to CHORIO who had a higher neonatal temperature at 30 minutes of life, were more likely to be admitted to the NICU and to have birth depression, than infants with lesser degree of temperature elevation after birth. Within the NICU group, the extent of temperature elevation was not associated with worse neurological outcomes.

Attenuated fever in pregnant rats is associated with blunted syntheses of brain cyclooxygenase-2 and PGE2

Attenuation of fever occurs in pregnant animals. This study examined a hypothesis that brain production of PGE(2), the final mediator of fever, is suppressed in pregnant animals. Near-term pregnant rats and age-matched nonpregnant female rats were injected with lipopolysaccharide (100 microg/kg) intraperitoneally. Four hours later, colonic temperature was measured, their cerebrospinal fluid (CSF) was sampled for PGE(2) assay, and their brains were processed for immunohistochemistry of cyclooxygenase-2, an enzyme involved in PGE(2) biosynthesis. In the pregnant rats, lipopolysaccharide injection resulted in significantly smaller elevations in both colonic temperature and CSF-PGE(2) level than in nonpregnant rats. In the pregnant rats, lipopolysaccharide-induced cyclooxygenase-2 expression was blunted in terms of the number of positive cells. There was a significant correlation between PGE(2) level in CSF and the number of cyclooxygenase-2-positive endothelial cells. These results suggest that suppressed PGE(2) production in the brain is one cause for the attenuated fever response at near-term pregnancy and that this suppressed PGE(2) production is due to the suppressed induction of cyclooxygenase-2 in brain endothelial cells.