Impact of clinical and/or histological chorioamnionitis on neurodevelopmental outcomes in preterm infants: A literature review

Histological chorioamnionitis and pathological stages on very preterm infant outcomes

AIMS

Histological chorioamnionitis (HCA) is a condition linked to preterm birth and neonatal infection and its relationship with various pathological stages in extremely preterm neonates, and with their associated short- and long-term consequences, remains a subject of research. This study investigated the connection between different pathological stages of HCA and both short-term complications and long-term outcomes in preterm infants born at or before 32 weeks of gestational age.

METHODS

Preterm infants born at ≤ 32 weeks of gestation who underwent placental pathology evaluation and were followed-up at 18-24 months of corrected age were included. Neonates were classified based on their exposure to HCA and were further subdivided into different groups according to maternal inflammatory responses (MIR) and fetal inflammatory responses (FIR) stages. We compared short-term complications during their hospital stay between the HCA-exposed and -unexposed groups and examined the influence of HCA stages on long-term outcomes.

RESULTS

The HCA group exhibited distinct characteristics such as higher rates of premature rupture of membranes > 18 h, reduced amniotic fluid, early-onset sepsis, bronchopulmonary dysplasia and intraventricular haemorrhage (IVH) grades III-IV (P < 0.05). The moderate-severe HCA group displayed lower gestational age, lower birth weight and higher incidence of IVH (grades III-IV) and preterm sepsis compared with the mild HCA group (P < 0.05). After adjusting for confounders, the MIR stages 2-3 group showed associations with cognitive impairment and cerebral palsy (P < 0.05), and the FIR stages 2-3 group also showed poor long-term outcomes and cognitive impairment (P < 0.05).

CONCLUSIONS

Moderate-severe HCA was associated with increased early-onset sepsis, severe IVH and poor long-term outcomes, including cognitive impairment and cerebral palsy. Vigilant prevention strategies are warranted for severe HCA cases in order to mitigate poorer clinical outcomes.

Intrauterine exposure to chorioamnionitis and neuroanatomical alterations at term-equivalent age in preterm infants

PURPOSE

Infants born to mothers with chorioamnionitis (CAM) are at increased risk of developing adverse neurodevelopmental disorders in later life. However, clinical magnetic resonance imaging (MRI) studies examining brain injuries and neuroanatomical alterations attributed to CAM have yielded inconsistent results. We aimed to determine whether exposure to histological CAM in utero leads to brain injuries and alterations in the neuroanatomy of preterm infants using 3.0- Tesla MRI at term-equivalent age.

METHODS

A total of 58 preterm infants born before 34 weeks of gestation at Nagoya University Hospital between 2010 and 2018 were eligible for this study (CAM group, n = 21; non-CAM group, n = 37). Brain injuries and abnormalities were assessed using the Kidokoro Global Brain Abnormality Scoring system. Gray matter, white matter, and subcortical gray matter (thalamus, caudate nucleus, putamen, pallidum, hippocampus, amygdala, and nucleus accumbens) volumes were evaluated using segmentation tools (SPM12 and Infant FreeSurfer).

RESULTS

The Kidokoro scores for each category and severity in the CAM group were comparable to those observed in the non-CAM group. White matter volume was significantly smaller in the CAM group after adjusting for covariates (postmenstrual age at MRI, infant sex, and gestational age) (p = 0.007), whereas gray matter volume was not significantly different. Multiple linear regression analyses revealed significantly smaller volumes in the bilateral pallidums (right, p = 0.045; left, p = 0.038) and nucleus accumbens (right, p = 0.030; left, p = 0.004) after adjusting for covariates.

CONCLUSIONS

Preterm infants born to mothers with histological CAM showed smaller volumes in white matter, pallidum, and nucleus accumbens at term-equivalent age.

Clinical Chorioamnionitis and Neurodevelopment at 5 Years of Age in Children Born Preterm: The EPIPAGE-2 Cohort Study

OBJECTIVE

To assess the association between clinical chorioamnionitis and neurodevelopmental disorders at 5 years of age in children born preterm.

STUDY DESIGN

EPIPAGE 2 is a national, population-based cohort study of children born before 35 weeks of gestation in France in 2011. We included infants born alive between 240/7 and 346/7 weeks after preterm labor or preterm premature rupture of membranes. Clinical chorioamnionitis was defined as maternal fever before labor (>37.8°C) with ≥2 of the following criteria: maternal tachycardia, hyperleukocytosis, uterine contractions, purulent amniotic fluid, or fetal tachycardia. The primary outcome was a composite, including cerebral palsy, coordination disorders, cognitive disorders, sensory disorders, or behavioral disorders. We also analyzed each of these disorders separately as secondary outcomes. We performed a multivariable analysis using logistic regression models. We accounted for the nonindependence of twins and missing data by generalized estimating equation models and multiple imputations, respectively.

RESULTS

Among 2927 children alive at 5 years of age, 124 (3%) were born in a context of clinical chorioamnionitis. Overall, 8.2% and 9.6% of children exposed and unexposed, respectively, to clinical chorioamnionitis had moderate-to-severe neurodevelopmental disorders. After multiple imputations and multivariable analysis, clinical chorioamnionitis was not associated with the occurrence of moderate-to-severe neurodevelopmental disorders (aOR, 0.9; 95% CI, 0.5-1.8).

CONCLUSIONS

We did not find any association between clinical chorioamnionitis and neurodevelopmental disorders at 5 years of age in children born at <35 weeks of gestation after preterm labor or preterm premature rupture of membrane.

Establishment of a prediction model for histological chorioamnionitis and its association with outcomes of premature infants

Aim

This study aims to construct a prediction model for histological chorioamnionitis (HCA) and analyze the associations between the predicted risk of HCA and adverse outcomes in preterm infants.

Methods

In total, 673 subjects were included in this cohort study and divided into HCA group (n = 195) and non-HCA group (n = 478). A stepwise method was used to screen the predictors for HCA, binary logistic regression was used to construct the prediction model, and the associations between the predicted risk of HCA and adverse outcomes were analyzed.

Results

HCA occurred in 195 patients, accounting for 29.0%. The sensitivity of the prediction model was 0.821 [95% confidence interval (CI): 0.767-0.874)], the specificity was 0.684 (95% CI: 0.642-0.726), the positive predictive value was 0.514 (0.459-0.570), the negative predictive value was 0.903 (95% CI: 0.873-0.934), the area under the curve was 0.821 (95% CI: 0.786-0.855), and the accuracy was 0.724 (95% CI: 0.690-0.757). The predicted risk of HCA was associated with a higher risk of bronchopulmonary dysplasia (BPD) [odds ratio (OR) = 3.48, 95% CI: 1.10-10.95)], sepsis (OR = 6.66, 95% CI: 2.17-20.43), and neonatal infections (OR = 9.85, 95% CI: 3.59-26.98), but not necrotizing enterocolitis (OR = 0.67, 95% CI: 0.24-1.88), retinopathy of prematurity (OR = 1.59, 95% CI: 0.37-6.85), and brain damage (OR = 1.77, 95% CI: 0.82-3.83). After adjusting for confounders including gestational week at birth and birth weight, the risk of neonatal infections (OR = 5.03, 95% CI: 2.69-9.41) was increased in preterm infants' exposure to HCA.

Conclusion

The model showed good predictive performance for identifying pregnant women with a higher risk of HCA. In addition, HCA was associated with the risk of BPD, sepsis, and infections in neonates.

Acute histologic chorioamnionitis independently and directly increases the risk for brain abnormalities seen on magnetic resonance imaging in very preterm infants

BACKGROUND

The independent risk for neurodevelopmental impairments attributed to chorioamnionitis in premature infants remains controversial. Delayed brain maturation or injury identified on magnetic resonance imaging at term-equivalent age can be used as a surrogate measure of neurodevelopmental impairments that is less confounded by postdelivery neonatal intensive care unit environmental factors to investigate this relationship more clearly.

OBJECTIVE

This study aimed to determine whether preterm infants born with moderate to severe acute histologic chorioamnionitis would have a higher magnetic resonance imaging-determined global brain abnormality score, independent of early premature birth, when compared with preterm infants with no or mild chorioamnionitis.

STUDY DESIGN

This was a prospective, multicenter cohort study involving infants born very prematurely ≤32 weeks' gestational age with acute moderate to severe histologic chorioamnionitis, graded using standard histologic criteria. Brain abnormalities were diagnosed and scored using a well-characterized, standardized scoring system captured using a high-resolution 3 Tesla magnetic resonance imaging research magnet. In secondary analyses, total brain volume and 4 magnetic resonance imaging metrics of cortical maturation (cortical surface area, sulcal depth, gyral index, and inner cortical curvature) were calculated using an automated algorithm and correlated with chorioamnionitis. The association of funisitis (any grade) with brain abnormalities was also explored. We investigated if premature birth mediated the relationship between histologic chorioamnionitis and brain abnormality score using mediation analysis.

RESULTS

Of 353 very preterm infants, 297 infants had mild or no chorioamnionitis (controls), and 56 were diagnosed with moderate to severe acute histologic chorioamnionitis. The primary outcome brain abnormality score was significantly higher in histologic chorioamnionitis-exposed infants than in the controls (median, 4 vs 7; P<.001). Infants with acute histologic chorioamnionitis had significantly lower brain tissue volume (P=.03) and sulcal depth (P=.04), whereas other morphometric indices did not differ statistically. In the multiple regression analysis, we observed persistent significant relationships between moderate to severe acute histologic chorioamnionitis and brain abnormality scores (β=2.84; 1.51-4.16; P<.001), total brain volume (P=.03), and sulcal depth (P=.02). Funisitis was also significantly associated with brain abnormality score after adjustment for clinical confounders (P=.005). Mediation analyses demonstrated that 50% of brain abnormalities was an indirect consequence of premature birth, and the remaining 50% was a direct effect of moderate to severe acute histologic chorioamnionitis when compared with preterm infants with no or mild chorioamnionitis exposure. Examining gestational age as a mediator, funisitis did not exert a significant direct effect on brain abnormalities after the significant indirect effects of preterm birth were accounted for.

CONCLUSION

Acute histologic chorioamnionitis increases the risk for brain injury and delayed maturation, both directly and indirectly, by inducing premature birth.

Temporal trends in intraventricular hemorrhage in preterm infants: A Brazilian multicenter cohort

BACKGROUND

Intraventricular hemorrhage (IVH) is a serious problem in preterm infants. Brazilian national data are unknown.

OBJECTIVE

To evaluate the incidence and temporal trend of IVH in very low birth weight (VLBW) preterm infants of 18 centers of the Brazilian Network on Neonatal Research.

STUDY DESIGN

National prospective multicenter cohort study including inborn VLBW preterm infants aged 23^0/7- 33^6/7 weeks' gestation, admitted between 2013 and 2018. The center with the mean incidence rate was used as reference. We applied two adjustments models using perinatal variables, and perinatal + neonatal diseases.

RESULTS

Of 6,420 infants, 1951/30.4% (range 27.1-33.8%) had IVH and the disease showed a significant trend towards an overall increase in incidence over time (p = 0.003), especially in three centers. Severe IVH (grade III or IV) occurred in 32.2% (range 29.2-34.5%) of those affected by IVH, with a stable incidence. After adjustments for perinatal variables, the differences persisted among centers: for global IVH, 7 centers had significantly lower rates (OR ranging from 0.31 to 0.62), and 2 presented rates higher than the reference center (OR ranging from 2.00 to 12.46) for severe HIV. Considering perinatal and neonatal variables, 6 centers had significantly lower rates (OR ranging from 0.36 to 0.60) for global IVH than the reference center and 3 had statistically higher rates (OR 1.72, 1.86 and 11.78) for severe forms.

CONCLUSION

The incidence rate of IVH in this Brazilian cohort was high and it revealed an increasing trend towards over time. The severe IVH rate was also worrisome.

Chorioamnionitis and neonatal outcomes

Chorioamnionitis or intrauterine inflammation is a frequent cause of preterm birth. Chorioamnionitis can affect almost every organ of the developing fetus. Multiple microbes have been implicated to cause chorioamnionitis, but "sterile" inflammation appears to be more common. Eradication of microorganisms has not been shown to prevent the morbidity and mortality associated with chorioamnionitis as inflammatory mediators account for continued fetal and maternal injury. Mounting evidence now supports the concept that the ensuing neonatal immune dysfunction reflects the effects of inflammation on immune programming during critical developmental windows, leading to chronic inflammatory disorders as well as vulnerability to infection after birth. A better understanding of microbiome alterations and inflammatory dysregulation may help develop better treatment strategies for infants born to mothers with chorioamnionitis.

Relationship between placental weight and late-onset circulatory collapse

BACKGROUND

Late-onset circulatory collapse (LCC) is a serious complication in preterm infants and is increasing in Japan. The underlying pathophysiology is thought to be relative adrenal insufficiency and it is more likely to develop at a young gestational age (GA) and in low birthweight (BW) infants. BW to placental weight ratio (BPR) is an index of pregnancy outcomes and early neonatal morbidity. We aimed to analyze the relationship between LCC and potential predicting factors including BPR.

METHODS

This retrospective study included 261 singletons born before 32 weeks of gestation between 2007 and 2017. Perinatal data, including the placental weight and BPR, were collected from medical records and were assessed for their relationship with LCC. Propensity score analysis was performed and matched factors were GA and BW.

RESULTS

Sixty-seven infants (25.7%) had LCC (median GA 27.4 weeks). GA and BW differed significantly between the LCC and non-LCC groups (P < 0.001, respectively). The placental weight and BPR of the LCC group were significantly lower than those of the non-LCC group, while Z-score of BPR did not differ significantly between the groups. After propensity score matching, there was a significant difference in the incidence of severe intraventricular hemorrhage (grades III-IV; P = 0.042), but no differences in BPR and Z-score of BPR between the groups.

CONCLUSION

In the propensity score analysis matched for GA and BW, there was no significant difference in perinatal factors including BPR between the LCC and non-LCC groups, except for incidence of severe intraventricular hemorrhage.

Association of Infection in Neonates and Long-Term Neurodevelopmental Outcome

Perinatal and neonatal infection and associated inflammatory response may adversely affect brain development and lead to neurodevelopmental impairment. Factors that predict the risk of infection and subsequent adverse outcomes have been identified but substantial gaps remain in identifying mechanisms and interventions that can alter outcomes. This article describes the current epidemiology of neonatal sepsis, the pathogenesis of brain injury with sepsis, and the reported long-term neurodevelopment outcomes among survivors.

Chorioamnionitis and neurodevelopmental outcome in very preterm infants from 2007 to 2017-a population-based study

AIM

The study compares neurodevelopmental outcome at 24 months corrected age of very preterm infants exposed to chorioamnionitis and controls. Peripartal parameters which may influence outcome are also investigated.

METHODS

In this observational population-based study, very preterm infants born between 2007 and 2017 were eligible (n = 466) and included if a histological placental examination and a complete neurodevelopmental assessment (Bayley Scale of Infant Development II or III) (n = 168) were performed. Secondary analyses were calculated to identify peripartal factors that significantly influence mental and psychomotor outcome.

RESULTS

Included infants showed a mean MDI of 91.2 (SD = 20.7) and a mean PDI of 99.4 (SD = 14.8). Infants with (n = 71) and without (n = 97) chorioamnionitis did not statistically differ either with mean MDI (91.8 vs. 90.3 points; p = 0.29) or mean PDI (98.3 vs. 100.9 points; p = 0.81), even after controlling for gestational age, mean APGAR scores and administration of antenatal steroids. Bronchopulmonary dysplasia was identified as the most influential factor for both MDI (p = .024) and PDI (p = .004).

CONCLUSION

We could not find an effect of chorioamnionitis on neurodevelopmental outcome of very preterm infants over an eleven-year period. Analysis shows that postnatal factors have higher impacts than does chorioamnionitis.

Chorioamnionitis in utero, schizophrenia in adulthood: limited current evidence-future research focus?

Background: Developmental adaptive processes during gestation that are known to be involved in permanent changes in physiology and metabolism or "early life programming" can adversely affect fetal brain development, impacting both brain structure and function.Data: Emerging evidence strongly supports the developmental origin of schizophrenia, which may potentially be a result of prenatal exposure to a diversity of factors, especially infections, in genetically predisposed subjects. Structural and functional brain changes during development of schizophrenia are determined by genetic components, altered expression of schizophrenia risk genes and epigenetic dysregulation. However, the precise mechanisms underlying these relationships remain unclear. Findings from human and animal studies suggest that inflammatory-immune responses and activation of oxidative stress pathways are crucial in mediating intrauterine infection-induced neurodevelopmental and neuropsychiatric diseases.Aim: Considering the high prevalence of intrauterine inflammation in the context of chorioamnionitis during human pregnancy and the paucity of knowledge on fetal programming of schizophrenia, this mini review aims to exclusively consolidate the current evidence supporting a potential association between chorioamnionitis and schizophrenia.

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.

Mechanisms of brain injury in newborn infants associated with the fetal inflammatory response syndrome

The fetal inflammatory response syndrome (FIRS) is characterized by umbilical cord inflammation and elevated fetal pro-inflammatory cytokines. Surviving neonates, especially very preterm infants, have increased rates of neonatal morbidity including neurodevelopmental impairment. The mechanism of brain injury in FIRS is complex and may involve "multiple hits." Exposure to in utero inflammation initiates a cascade of the fetal immune response, where pro-inflammatory cytokines can cause direct injury to oligodendrocytes and neurons. Activation of microglia results in further injury to vulnerable pre-myelinating oligodendrocytes and influences the integrity of the fetal and newborn's blood-brain barrier, resulting in further exposure of the brain to developmental insults. Newborns exposed to FIRS are frequently exposed to additional perinatal and postnatal insults that can result in further brain injury. Future directions should include evaluations for new therapeutic interventions aimed at reducing brain injury by dampening FIRS, inhibition of microglial activation, and regeneration of immature oligodendrocytes.

Association of Chorioamnionitis with Cerebral Palsy at Two Years after Spontaneous Very Preterm Birth: The EPIPAGE-2 Cohort Study

OBJECTIVE

To assess whether chorioamnionitis is associated with cerebral palsy (CP) or death at 2 years' corrected age in infants born before 32 weeks of gestation after spontaneous birth.

STUDY DESIGN

EPIPAGE-2 is a national, prospective, population-based cohort study of children born preterm in France in 2011; recruitment periods varied by gestational age. This analysis includes infants born alive after preterm labor or preterm premature rupture of membranes from 24^0/7 to 31^6/7 weeks of gestation. We compared the outcomes of CP, death at 2 years' corrected age, and "CP or death at age 2" according to the presence of either clinical chorioamnionitis or histologic chorioamnionitis. All percentages were weighted by the duration of the recruitment period.

RESULTS

Among 2252 infants born alive spontaneously before 32 weeks of gestation, 116 (5.2%) were exposed to clinical chorioamnionitis. Among 1470 with placental examination data available, 639 (43.5%) had histologic chorioamnionitis. In total, 346 infants died before 2 years and 1586 (83.2% of the survivors) were evaluated for CP at age 2 years. CP rates were 11.1% with and 5.0% without clinical chorioamnionitis (P = .03) and 6.1% with and 5.3% without histologic chorioamnionitis (P = .49). After adjustment for confounding factors, CP risk rose with clinical chorioamnionitis (aOR 2.13, 95% CI 1.12-4.05) but not histologic chorioamnionitis (aOR 1.21, 95% 0.75-1.93). Neither form was associated with the composite outcome "CP or death at age 2."

CONCLUSIONS

Among infants very preterm born spontaneously, the risk of CP at a corrected age of 2 years was associated with exposure to clinical chorioamnionitis but not histologic chorioamnionitis.

Microbial invasion of the amniotic cavity is associated with impaired cognitive and motor function at school age in preterm children

BACKGROUND

Chorioamnionitis is an important cause of preterm delivery. Data on neurodevelopmental outcome in exposed infants are inconsistent due to difficulties in diagnosing intrauterine infection/inflammation and lack of detailed long-term follow-up. We investigate cognitive and motor function in preterm infants at early school age and relate the findings to bacteria in amniotic fluid obtained by amniocentesis (microbial invasion of the amniotic cavity (MIAC)) or placenta findings of histological chorioamnionitis (HCA) or fetal inflammatory response syndrome (FIRS).

METHOD

Sixty-six infants with gestational age <34 weeks at birth and without major disabilities were assessed using WISC-III and the Bruininks-Oseretsky Test of Motor Proficiency. Results were corrected for gestational age and sex.

RESULTS

Children exposed to MIAC had significantly lower scores for full-scale IQ and verbal IQ compared to the non-MIAC group and the difference in full-scale IQ remained after correction for confounding factors. The MIAC group had also significantly lower motor scores after correction. In contrast, motor function was not affected in infants exposed to HCA or FIRS and differences between groups for cognitive scores were lost after corrections.

CONCLUSION

Exposure to bacteria in amniotic fluid is associated with lower motor and cognitive scores in school age preterm infants without major disabilities.

Histological chorioamnionitis, antenatal steroids, and neonatal outcomes in very low birth weight infants: A nationwide study

Background

The aim of this study was to investigate whether some associations between histological chorioamnionitis (HCA) and favorable neonatal outcomes might be linked to those of antenatal steroids (AS) by determining the separate as well as the combined associations of HCA and AS with neonatal outcomes in very low birth weight infants (VLBWIs).

Methods

This was a population-based study of VLBWIs born at 20–33 weeks’ gestation between January 2013 and December 2015 from the Korean Neonatal Network. A total of 4652 VLBWIs were enrolled for prevalence study. Of these, 2900 singleton VLBWIs were used for outcome analyses to evaluate individual associations of HCA and AS simultaneously with correction for potential perinatal factors and an interaction term of HCA and AS.

Results

The overall prevalence of HCA was 34.9% (1623 VLBWIs). Multivariable logistic regression demonstrated that HCA was associated with decreased mortality (adjusted odds ratio [aOR], 0.51; 95% confidence interval [CI], 0.29–0.91; P = 0.022), AS were associated with reduction in mortality (aOR, 0.59; 95% CI, 0.39–0.90; P = 0.014) and neonatal seizure (aOR, 0.57; 95% CI, 0.37–0.86; P = 0.008), and a combination of HCA and AS was associated with remarkably lowered severe intraventricular hemorrhage by interacting with each other (aOR, 0.47; 95% CI, 0.25–0.88; P = 0.019).

Conclusions

We suggest that in VLBWIs HCA and AS may be favorable independent factors for neonatal outcome and may also work in synergy for neuroprotection.

Neuroprotection from acute brain injury in preterm infants

Infants born at ≤32⁺⁶ weeks gestation are at higher risk for intracranial ischemic and hemorrhagic injuries, which often occur in the first 72 hours postbirth. Antenatal strategies to reduce the incidence of acute brain injuries include administering maternal corticosteroids and prompt antibiotic treatment for chorioamnionitis. Perinatal strategies include delivery within a tertiary centre, delayed cord clamping, and preventing hypothermia. Postnatal strategies include empiric treatment with antibiotics when chorioamnionitis is suspected, the cautious use of inotropes, the avoidance of blood PCO2 fluctuation, and neutral head positioning. Clinicians should be aware of the policies and procedures that, especially when combined, can provide neuroprotection for preterm infants.

Prenatal Risk Factors for Adverse Developmental Outcome in Preterm Infants-Systematic Review

Background: Preterm infants are still at an increased risk for suboptimal neurodevelopmental outcomes when compared with term born infants. The development of a child born preterm can be jeopardized by suboptimal conditions during pregnancy, in addition to the suboptimal growth environment postnatally compared to the normal in utero environment. This review summarizes the literature on the role of chorioamnionitis, placental insufficiency, and maternal smoking on the developmental outcomes of preterm infants. Methods: A systematic database search was performed to identify all original articles published on or before September 12, 2018 that evaluated the impact of clinical or histological chorioamnionitis, abnormal prenatal fetal and placental blood flow, and prenatal smoking exposure on the neuropsychological and cognitive outcomes of preterm infants. We identified a total of 54 studies. Thirty five original articles evaluated the effects of clinical or histological chorioamnionitis; 15 studies evaluated the effects of abnormal blood flow patterns; and four studies evaluated the effects of maternal smoking during pregnancy. Results: The studies on prenatal risk factors showed conflicting results about the impact on the neurodevelopment of preterm infants. The majority of the studies did not show that chorioamnionitis poses a direct risk to the development of preterm infants. The role of abnormal prenatal placental and fetal blood flow on the development of preterm infants remained inconclusive because the sample sizes were often small and methodological problems complicated the interpretation of the data. Maternal smoking during pregnancy was assessed only in one cohort which showed that maternal smoking is a risk for suboptimal cognitive and neuropsychological development in preterm infants. Conclusions: This review summarizes the data on several prenatal risk factors which play a role in the developmental outcomes of preterm infants. To optimize the developmental outcomes, we need to first optimize the fetal wellbeing before birth. More research that extends from the fetal life to long-term developmental outcomes is needed.

[Diagnosis and management of intra-uterine infection: CNGOF Preterm Premature Rupture of Membranes Guidelines]

OBJECTIVE

To determine the diagnosis criteria and management of intra-uterine inflammation or infection (Triple I, III).

METHODS

PubMed and Cochrane Central databases search.

RESULTS

III is defined as an infection of the fetal membranes, and/or other components like the decidua, fetus, amniotic fluid or placenta. This word should be preferred to the word chorioamnionitis that is less precise (Professional consensus). III clinical signs exhibit poor limited sensibility and specificity (EL3). The diagnosis of III is retained in case of maternal fever (defined by a body temperature≥38°C) with no alternative cause identified and at least 2 signs among the following: fetal tachycardia>160 bpm for 10min or longer, uterine pain of labor, purulent fluid from the cervical canal (Professional consensus). Maternal hyperleukocytosis>20 giga/L in the absence of corticosteroids treatment or increased plasmatic C-reactive protein also argue for III, despite their limited sensibility and specificity (EL3). III requires prompt delivery (Grade A). III is not by itself an indication for cesarean delivery (Professional consensus). Antibiotic treatment should cover Streptococcus agalactiae and Escherichia coli. Antibiotics should be started immediately and maintained all over delivery, to reduce neonatal and maternal morbidity (Grade B). Treatment should rely on a combination of betalactamin and aminoglycoside (Grade B). After vaginal delivery, one single dose of antibiotic is required. Antibiotic duration should be longer in case of bacteremia. Longer duration could be considered in case of persistent fever or of cesarean delivery (Professional consensus).

[Epidemiology, risk factors and child prognosis: CNGOF Preterm Premature Rupture of Membranes Guidelines]

OBJECTIVES

To synthetize the available evidence regarding the incidence and risk factors of preterm premature rupture of membranes (PPROM). To describe the evolution of pregnancy, neonatal outcomes and the prognosis of infants born in a context of PPROM, according to the existence of an associated intrauterine infection and to the latency duration.

METHOD

Consultation of the Medline database, from 1980 to February 2018.

RESULTS

PPROM before 37 and before 34 weeks' gestation occur in 2-3% and <1% of pregnancies, respectively (LE2). Although many risk factors are identified, few are modifiable, and the vast majority of patients have no risk factors (LE2). Consequently, individual prediction of the risk of PPROM and primary prevention measures have not been shown to be effective and are not recommended in clinical practice (Grade B). Most women give birth within the week following PPROM (LE2). The main complications of PPROM are prematurity, intrauterine infection and obstetric and maternal complications (LE2). Latency duration and the frequency of complications decrease with increasing gestational age at PPROM (LE2). Neonatal prognosis is largely conditioned by gestational age at birth, with no apparent over-risk of poor outcomes linked to PPROM compared to other causes of preterm birth (LE2). In contrast, intrauterine infection is associated with an increased risk of in utero fetal death (LE3), necrotizing enterocolitis (LE1) and early-onset sepsis (LE2). The association of intrauterine infection with neurological morbidity remains controversial. Prolongation of latency, from gestational age at PPROM, is beneficial for the child (LE2).

CONCLUSION

PPROM is a major cause of prematurity and short- and long-term mortality and morbidity. Antenatal care is an important issue for obstetric and pediatric teams, aiming to reduce complications and adverse consequences for both mother and child.

[In the case of premature live birth, is very early rupture of the membranes an additional risk factor for morbidity and mortality?]

OBJECTIVE

To describe survival rate after preterm premature rupture of membranes (PPROM) before 25 weeks of gestation and compare neonatal morbidity and mortality among those born alive with a control group of infants born at a similar gestational age without premature rupture of membranes.

METHODS

We conducted a retrospective single-centre study at Port-Royal maternity, from 2007 to 2015, comparing neonatal outcomes between liveborninfants exposed to PPROM prior to 25 weeks of gestation (WG) and a control group not exposed to premature rupture of the membranes. For each live-born child, the next child born after spontaneous labor without PPROM was matched for gestational age at birth, sex, and whether or not they received antenatal corticosteroid therapy. The primary endpoint was severe neonatal complications assessed by a composite endpoint including neonatal deaths, grade 3-4 HIV, bronchopulmonary dysplasia, leukomalacia and stade 3-4 retinopathies.

RESULTS

Among 77 cases of very premature rupture of the membranes, 55 children were born alive. Among these, the average gestational age at birth was 28 WG and 1 day. The rate of severe neonatal complications did not differ between the two groups (43.6% in the PPROM group vs. 36.4%, P=0.44) and the survival rate at discharge was also similar in the two groups (85.5% vs. 83.6%, P=0.98).

CONCLUSIONS

In our cohort and among livebirths after 24 WG, PPROM before 25 WG was not associated with an increased risk of morbidity and mortality compared to children born at the same gestational age after a spontaneous labor with intact membranes.