Cerebral palsy and chorioamnionitis: the inflammatory cytokine link

Perinatal Outcomes of Late Preterm Rupture of Membranes with or without Latency Antibiotics

OBJECTIVE

 This study aimed to examine whether the addition of latency antibiotics in late preterm rupture of membranes (ROM) decreases neonatal infection and increases latency.

STUDY DESIGN

 This retrospective two-center study was conducted at Holy Family Hospital (HFH) in Nazareth and Emek Medical Center (EMC) in Afula, on data collected between January 2017 and April 2023. HFH is the smaller institution. EMC and HFH implement similar policies regarding ROM at 340/7 to 366/7 weeks' gestation; the only difference is that a 10-day course of latency antibiotics is implemented at EMC. All women with ROM between 340/7 and 366/7 weeks' gestation who were admitted to one of the centers during the study period, and had a live fetus without major malformations, were included. The primary outcome was neonatal sepsis rate. Secondary outcomes included a composite of neonatal sepsis, mechanical ventilation ≥24 hours, and perinatal death. Additionally, gestational age at delivery and delivery mode were examined.

RESULTS

 Overall, 721 neonates were delivered during the study period: 534 at EMC (where latency antibiotics were administered) and 187 at HFH. The gestational age at ROM was similar (35.8 and 35.9 weeks, respectively, p = 0.14). Neonatal sepsis occurred in six (1.1%) neonates at EMC and one (0.5%) neonate at HFH (adjusted p = 0.71; OR: 1.69; 95% Confidence Interval [CI]: 0.11-27.14). The composite secondary outcome occurred in nine (1.7%) and three (1.6%) neonates at EMC and HFH, respectively (adjusted p = 0.71; OR: 0.73; 95% CI: 0.14-3.83). The gestational age at delivery was 36.1 and 36.2 weeks at EMC and HFH, respectively (mean difference: 5 h; adjusted p = 0.02). The cesarean delivery rate was 24.7% and 19.3% at EMC and HFH, respectively (adjusted p = 0.96).

CONCLUSION

 Latency antibiotics administered to women admitted with ROM between 340/7 and 366/7 weeks' gestation did not decrease the rate of neonatal sepsis.

KEY POINTS

· Latency antibiotics in late preterm ROM does not decrease neonatal sepsis.. · Latency antibiotics in late preterm ROM does not prolong gestational age at delivery.. · Latency antibiotics in late preterm ROM does not affect the mode of delivery..

Sex-specific association between placental inflammatory cytokine mRNA expression and preschoolers' behavioral development: The Ma'anshan birth cohort study

BACKGROUND

Placental inflammation may contribute to brain abnormalities and childhood neuropsychiatric disorders, but limited knowledge is available on the association of placental inflammatory cytokine levels and offspring's behavioral development. This study aimed to examine the sex-specific association between placental inflammatory cytokine mRNA expression and preschoolers' behavioral development.

METHODS

3474 pregnant women were recruited as the initial study population in the Ma'anshan birth cohort (MABC) study. Placentas (n = 2519) were collected during childbirth, and the mRNA expression of IL-8, IL-1β, CRP, TNF-α, IL-6, IL-10, and IL-4 was assessed. The Child Behavior Checklist 1.5-5 (CBCL 1.5-5) was used to assess children's behavioral development at 4 years old. A T-score ≥ 60 on summary scales or a score ≥ 65 on syndrome scales was regarded as the borderline clinical range. Multiple linear regression models and binary logistic regression models were applied to explore the sex-specific associations between placental inflammatory cytokines mRNA transcript levels and preschoolers' behavioral development.

RESULTS

Sex-specific associations between placental inflammatory cytokines mRNA expression and preschoolers' behavioral development were observed. There was a positive association between IL-8 and CBCL scores for boys on anxious/depressed problems, aggressive behaviors, externalizing problems and total problems. Logistic regression models showed that high levels of IL-8 were associated with a higher risk of girls' emotionally reactive problems and sleep problems compared to low/medium levels. High TNF-α was correlated with increased sleep problem scores in boys, and medium TNF-α (vs. low levels) was associated with an increased risk of girls' externalizing problems. Medium levels of CRP, IL-1β, and IL-6 were found to be associated with a decreased risk of girls' behavioral problems compared to low/high levels. For anti-inflammatory cytokines, medium IL-10 and IL-4 (vs. low levels) were observed to be associated with a lower risk of internalizing problems in boys and externalizing problems in girls, respectively. High IL-10 was correlated with decreased attention problem scores in boys.

CONCLUSION

This study indicates that placental inflammatory cytokine mRNA expression of IL-8, CRP, TNF-α, IL-1β, IL-4 and IL-10 may be associated with preschoolers' behavioral development in a sex-specific manner.

The anti-inflammatory role of placental Hofbauer cells is altered in patients with chorioamnionitis: Are CYP2C8 and soluble epoxide hydrolase involved in immunomodulation?

AIMS

Hofbauer cells (HBCs) are placental macrophages playing various roles during normal and complicated pregnancies, and of the latter, chorioamnionitis is the most frequent.

METHODS

In placenta with chorioamnionitis, we examined immunohistochemical expression profiles of IL-1β, IL-10, and their potential regulators, CYP2C8 and soluble epoxide hydrolase (sEH), in Hofbauer cells and compared the results with our previously published data for normal placenta.

RESULTS

We found that the expression profiles of the studied proteins in Hofbauer cells in chorioamnionitis differs from normal placenta. In chorioamnionitis, HBCs showed a moderate expression of IL-1β together with a weak expression of IL-10 and CYP2C8. Contrary to normal placenta, HBCs in chorioamnionitis express sEH. We demonstrated a moderate positive correlation between the expression of CYP2C8 and sEH in chorioamnionitis (Spearman r = 0.5654), suggesting enhanced degradation of anti-inflammatory epoxyeicosatrienoic acids. Moreover, the relations of IL-1β and IL-10 to CYP2C8, previously described in normal placenta, disappeared. Furthermore, a weak expression of anti-inflammatory IL-10 in chorioamnionitis was accompanied by change in circularity of HBCs (Spearman r = 0.8193).

CONCLUSION

Taken together, these findings suggest a possible alteration of the anti-inflammatory role of HBCs and its regulation in chorioamnionitis.

Increased Soluble Epoxide Hydrolase in Human Gestational Tissues from Pregnancies Complicated by Acute Chorioamnionitis

Chorioamnionitis (CAM) is primarily a polymicrobial bacterial infection involving chorionic and amniotic membranes that is associated with increased risk of preterm delivery. Epoxyeicosatrienoic acids (EETs) are eicosanoids generated from arachidonic acid by cytochrome P450 enzymes and further metabolized mainly by soluble epoxide hydrolase (sEH) to produce dihydroxyeicosatrienoic acids (DHETs). As a consequence of this metabolism of EETs, sEH reportedly exacerbates several disease states; however, its role in CAM remains unclear. The objectives of this study were to (1) determine the localization of sEH and compare the changes it undergoes in the gestational tissues (placentas and fetal membranes) of women with normal-term pregnancies and those with pregnancies complicated by acute CAM; (2) study the effects of lipopolysaccharide (LPS) on the expression of sEH in the human gestational tissues; and (3) investigate the effect of 12-(3-adamantan-1-yl-ureido)-dodecanoic acid (AUDA), a specific sEH inhibitor, on LPS-induced changes in 14,15-DHET and cytokines such as interleukin- (IL-) 1β and IL-6 in human gestational tissues in vitro and in pregnant mice. We found that women with pregnancies complicated by acute CAM had higher levels of sEH mRNA and protein in fetal membranes and villous tissues compared to those in women with normal-term pregnancies without CAM. Furthermore, fetal membrane and villous explants treated with LPS had higher tissue levels of sEH mRNA and protein and 14,15-DHET than those present in the vehicle controls, while the administration of AUDA in the media attenuated the LPS-induced production of 14,15-DHET in tissue homogenates and IL-1β and IL-6 in the media of explant cultures. Administration of AUDA also reduced the LPS-induced changes of 14,15-DHET, IL-1β, and IL-6 in the placentas of pregnant mice. Together, these results suggest that sEH participates in the inflammatory changes in human gestational tissues in pregnancies complicated by acute CAM.

Planned early birth versus expectant management for women with preterm prelabour rupture of membranes prior to 37 weeks' gestation for improving pregnancy outcome

BACKGROUND

Current management of preterm prelabour rupture of the membranes (PPROM) involves either initiating birth soon after PPROM or, alternatively, adopting a 'wait and see' approach (expectant management). It is unclear which strategy is most beneficial for mothers and their babies. This is an update of a Cochrane review published in 2010 (Buchanan 2010).

OBJECTIVES

To assess the effect of planned early birth versus expectant management for women with preterm prelabour rupture of the membranes between 24 and 37 weeks' gestation for fetal, infant and maternal well being.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register (30 September 2016), and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials comparing planned early birth with expectant management for women with PPROM prior to 37 weeks' gestation. We excluded quasi-randomised trials.

DATA COLLECTION AND ANALYSIS

Two review authors independently evaluated trials for inclusion into the review and for methodological quality. Two review authors independently extracted data. We checked data for accuracy. We assessed the quality of evidence using the GRADE approach.

MAIN RESULTS

We included 12 trials in the review (3617 women and 3628 babies). For primary outcomes, we identified no clear differences between early birth and expectant management in neonatal sepsis (risk ratio (RR) 0.93, 95% confidence interval (CI) 0.66 to 1.30, 12 trials, 3628 babies, evidence graded moderate), or proven neonatal infection with positive blood culture (RR 1.24, 95% CI 0.70 to 2.21, seven trials, 2925 babies). However, early birth increased the incidence of respiratory distress syndrome (RDS) (RR 1.26, 95% CI 1.05 to 1.53, 12 trials, 3622 babies, evidence graded high). Early birth was also associated with an increased rate of caesarean section (RR 1.26, 95% CI 1.11 to 1.44, 12 trials, 3620 women, evidence graded high).Assessment of secondary perinatal outcomes showed no clear differences in overall perinatal mortality (RR 1.76, 95% CI 0.89 to 3.50, 11 trials, 3319 babies), or intrauterine deaths (RR 0.45, 95% CI 0.13 to 1.57, 11 trials, 3321 babies) when comparing early birth with expectant management. However, early birth was associated with a higher rate of neonatal death (RR 2.55, 95% CI 1.17 to 5.56, 11 trials, 3316 babies) and need for ventilation (RR 1.27, 95% CI 1.02 to 1.58, seven trials, 2895 babies, evidence graded high). Babies of women randomised to early birth were delivered at a gestational age lower than those randomised to expectant management (mean difference (MD) -0.48 weeks, 95% CI -0.57 to -0.39, eight trials, 3139 babies). Admission to neonatal intensive care was more likely for those babies randomised to early birth (RR 1.16, 95% CI 1.08 to 1.24, four trials, 2691 babies, evidence graded moderate).In assessing secondary maternal outcomes, we found that early birth was associated with a decreased rate of chorioamnionitis (RR 0.50, 95% CI 0.26 to 0.95, eight trials, 1358 women, evidence graded moderate), and an increased rate of endometritis (RR 1.61, 95% CI 1.00 to 2.59, seven trials, 2980 women). As expected due to the intervention, women randomised to early birth had a higher chance of having an induction of labour (RR 2.18, 95% CI 2.01 to 2.36, four trials, 2691 women). Women randomised to early birth had a decreased total length of hospitalisation (MD -1.75 days, 95% CI -2.45 to -1.05, six trials, 2848 women, evidence graded moderate).Subgroup analyses indicated improved maternal and infant outcomes in expectant management in pregnancies greater than 34 weeks' gestation, specifically relating to RDS and maternal infections. The use of prophylactic antibiotics were shown to be effective in reducing maternal infections in women randomised to expectant management.Overall, we assessed all 12 studies as being at low or unclear risk of bias. Some studies lacked an adequate description of methods and the risk of bias could only be assessed as unclear. In five of the studies there were one and/or two domains where the risk of bias was judged as high. GRADE profiling showed the quality of evidence across all critical outcomes to be moderate to high.

AUTHORS' CONCLUSIONS

With the addition of five randomised controlled trials (2927 women) to this updated review, we found no clinically important difference in the incidence of neonatal sepsis between women who birth immediately and those managed expectantly in PPROM prior to 37 weeks' gestation. Early planned birth was associated with an increase in the incidence of neonatal RDS, need for ventilation, neonatal mortality, endometritis, admission to neonatal intensive care, and the likelihood of birth by caesarean section, but a decreased incidence of chorioamnionitis. Women randomised to early birth also had an increased risk of labour induction, but a decreased length of hospital stay. Babies of women randomised to early birth were more likely to be born at a lower gestational age.In women with PPROM before 37 weeks' gestation with no contraindications to continuing the pregnancy, a policy of expectant management with careful monitoring was associated with better outcomes for the mother and baby.The direction of future research should be aimed at determining which groups of women with PPROM would not benefit from expectant management. This could be determined by analysing subgroups according to gestational age at presentation, corticosteroid usage, and abnormal vaginal microbiological colonisation. Research should also evaluate long-term neurodevelopmental outcomes of infants.

Prolonged latency of preterm premature rupture of membranes and risk of cerebral palsy (.)

OBJECTIVE

To determine whether prolonged latency after preterm premature rupture of membranes (PPROM) is associated with an increased risk of death or moderate-to-severe cerebral palsy (CP).

STUDY DESIGN

This secondary analysis of the randomized controlled trial of magnesium sulfate for the prevention of CP evaluated whether the time interval between diagnosis of PPROM and delivery was associated with increased risk for CP. Prolonged latency was defined as an interval of ≥4 weeks, latency time was also categorized by week of latency for further analysis. The primary outcome was death or moderate-to-severe CP at 2 years of age. Logistic regression was used to control for confounders.

RESULTS

In all, 1522 patients with PPROM were analyzed; of whom, 1328 had a <4-week interval and 194 had an interval of ≥4 weeks. In the unadjusted analysis, the primary outcome was less likely in the PPROM ≥4 weeks group 4.1% versus 8.4%, RR: 0.49, 95% CI: 0.24-0.98. After adjusting for possible confounders, there was no statistical difference associated with PPROM latency ≥4 weeks versus <4 weeks for death or moderate-to-severe CP.

CONCLUSION

Prolonged exposure to an intrauterine environment of PPROM does not increase risk for CP.

A point of care test for interleukin-6 in amniotic fluid in preterm prelabor rupture of membranes: a step toward the early treatment of acute intra-amniotic inflammation/infection

OBJECTIVE

Preterm prelabor rupture of membranes (preterm PROM) accounts for 30-40% of spontaneous preterm deliveries and thus is a major contributor to perinatal morbidity and mortality. An amniotic fluid (AF) interleukin-6 (IL-6) concentration is a key cytokine for the identification of intra-amniotic inflammation, patients at risk of impending preterm delivery and adverse pregnancy complications. The conventional method to determine IL-6 concentrations in AF is an enzyme-linked immunosorbent assay (ELISA). However, this technique is not available in clinical settings, and the results may take several days. A lateral flow-based immunoassay, or point of care (POC) test, has been developed to address this issue. The objective of this study was to compare the performance of AF IL-6 determined by the POC test to that determined by ELISA for the identification of intra-amniotic inflammation in patients with preterm PROM.

MATERIALS AND METHODS

This retrospective cohort study includes 56 women with singleton pregnancies who presented with preterm PROM. Amniocentesis was performed at the time of diagnosis, and AF was analyzed using cultivation techniques for aerobic and anaerobic bacteria as well as genital mycoplasmas. AF Gram stain and AF white blood cell counts were determined. AF IL-6 concentrations were measured using both lateral flow-based immunoassay and ELISA. The primary outcome was intra-amniotic inflammation defined as AF ELISA IL-6 ≥ 2600 pg/ml. A previously determined cut-off of 745 pg/ml was used to define a positive POC test.

RESULTS

(1) The POC test for AF IL-6 concentrations had 97% sensitivity and 96% specificity for the identification of intra-amniotic inflammation, as defined using ELISA among patients with preterm PROM and (2) the diagnostic performance of the POC test for IL-6 was strongly correlated to that of an ELISA test for the identification of intra-amniotic inflammation and was equivalent for the identification of acute inflammatory placental lesions and microbial invasion of the amniotic cavity (MIAC).

CONCLUSION

A POC AF IL-6 test can identify intra-amniotic inflammation in patients with preterm PROM. Results can be available within 20 min - this makes it possible to implement interventions designed to treat intra-amniotic inflammation and improve pregnancy outcomes.

The relationship between the intensity of intra-amniotic inflammation and the presence and severity of acute histologic chorioamnionitis in preterm gestation

OBJECTIVE

Acute histologic chorioamnionitis (HCA) is associated with an increased risk of perinatal mortality and morbidity. The purpose of this study was to determine the relationship between the intensity of intra-amniotic inflammation (IAI) and the severity of acute HCA in preterm gestation.

METHODS

The relationship between the intensity of IAI and the presence and severity of acute HCA was examined in 412 patients with singleton gestations who delivered within 120 h of transabdominal amniocentesis. The concentration of amniotic fluid (AF) matrix metalloproteinase (MMP)-8 was assayed to determine the presence and intensity of IAI. Acute HCA was defined as the presence of inflammatory change in any tissue samples according to the criteria previously reported. The total grade of acute HCA was used to determine the severity of HCA.

RESULTS

(1) Patients with IAI had a significantly higher rate of acute HCA than those without IAI [76.9% (133/173)] versus 20.9% (50/239), p < 0.001]. The AF MMP-8 concentration was significantly higher in patients with acute HCA than in those without acute HCA (median [range]; 188.3 ng/ml [0.3-6142.6] versus 1.8 ng/ml [0.3-2845.5], p < 0.001); (2) Of 183 patients with acute HCA, the AF MMP-8 concentration was positively correlated with the severity of acute HCA (p < 0.001).

CONCLUSIONS

AF MMP-8 concentration was not only a predictor of the presence of acute HCA, but its concentration also correlated with the severity of acute HCA. The higher the intensity of IAI, the worse the degree of acute HCA in preterm gestation.

Chorioamnionitis and cerebral palsy: lessons from a patient registry

AIM

The fetal neuroinflammatory response has been linked to the development of brain injury in newborns and subsequent neurologic impairment. We aimed to explore the maternal and child factors associated with histologic chorioamnionitis in cerebral palsy.

METHODS

We conducted an observational study on a cohort of children with cerebral palsy who were identified from the Quebec Cerebral Palsy Registry. Placental pathology was reported prospectively. Maternal and child factors associated with histological chorioamnionitis were explored.

RESULTS

Placental reports were available in 455 of 534 (85%) children with cerebral palsy, and of these 12% had histological signs of chorioamnionitis on reports. These children were more likely to have large placentas over 90th percentile for gestational age (53.7% versus 30.7%, p = 0.001) and were born significantly more prematurely (<32 weeks in 51.9% vs 24.1%, p = 0.007) than children without chorioamnionitis. A clinical sign of perinatal infection was reported in 61.1% of children with chorioamnionitis, however each clinical sign was seen in a minority of these children. Children with chorioamnionitis were more likely to have spastic diplegic cerebral palsy subtype (37% vs 19.2%, p = 0.003) and periventricular white matter injury on neuroimaging (52.9% vs 35.8%, p = 0.004). However no differences in neuroimaging or subtypes were seen when stratified by prematurity.

DISCUSSION

Histological chorioamnionitis was a frequent pathological finding in children with cerebral palsy born prematurely, with larger placentas relative to gestation and birth weight. Future case control studies are needed to shed light on the role of inflammatory placental findings in pregnancy outcomes.

Cerebral palsy and perinatal infection in children born at term

OBJECTIVE

To investigate the link between infection-related risk factors for cerebral palsy subtypes in children born at term.

METHODS

A case-control study was performed in a population-based series of children with cerebral palsy born at term (n=309) matched with a control group (n=618). The cases were divided into cerebral palsy subtypes: spastic hemiplegia, spastic diplegia, spastic tetraplegia, and dyskinetic cerebral palsy. All forms of spastic cerebral palsy were also analyzed together. All records were examined for maternal and neonatal signs of infection. Univariate and adjusted analyses were performed.

RESULTS

Infection-related risk factors were shown to be independent risk factors for spastic cerebral palsy in the adjusted analyses. This was especially pronounced in the subgroup with spastic hemiplegia in which bacterial growth in urine during pregnancy (n=11 [7.5%], odds ratio [OR] 4.7, 95% confidence interval [CI] 1.5-15.2), any infectious disease during pregnancy (n=57 [39.0%], OR 2.9, 95% CI 1.7-4.8), severe infection during pregnancy (n=12 [8.2%], OR 15.4, 95% CI 3.0-78.1), antibiotic therapy once during pregnancy (n=33 [22.6%], OR 6.3, 95% CI 3.0-15.2) as well as several times during pregnancy (n=9 [6.2%], OR 15.6, 95% CI 1.8-134.2) constituted strong independent risk factors. However, only neonatal infection (n=11 [9.1%], OR 14.7, 95% CI 1.7-126.5) was independently significantly associated with an increased risk of spastic diplegia and tetraplegia.

CONCLUSIONS

Infection-related factors are strong independent risk factors for the subgroup with spastic hemiplegia in children with cerebral palsy born at term. The finding is less pronounced in the subgroups with spastic diplegia or tetraplegia.

LEVEL OF EVIDENCE

II.

Histologic chorioamnionitis and acute neurologic impairment in premature infants

OBJECTIVE

To determine if histologic chorioamnionitis is associated with acute neurologic impairment as evaluated by auditory brainstem response in premature infants.

METHODS

A prospective study was performed to compare auditory neural function at birth between premature infants with maternal histologic chorioamnionitis and infants without maternal histologic chorioamnionitis. Our inclusion criteria was 28-33 weeks gestational age (GA) infants who had maternal placental histopathology performed. Infants with toxoplasmosis, other infections, rubella, cytomegalovirus and herpes simplex (TORCH) infections, chromosomal disorders, cranio-facial anomalies and/or unstable condition were excluded. Bilateral monaural auditory brainstem evoked responses were performed using 80 dB nHL click stimuli at a repetition rate of 29.9/s within 48 h after birth.

RESULTS

Of 101 infants who met study criteria, 29 infants were born with history of maternal histologic chorioamnionitis. There were no significant differences between infants with histologic chorioamnionitis and infants without histologic chorioamnionitis in perinatal factors except for GA, pregnancy induced hypertension, and exposure to antenatal magnesium sulphate. After controlling for confounders, histologic chorioamnionitis was not associated with prolonged absolute wave latencies I, III, and V and/or decreased frequency of mature auditory waveform compared to infants without histologic chorioamnionitis.

CONCLUSION

Histologic chorioamnionitis is not associated with neurologic impairment at birth in premature infants.

Planned early birth versus expectant management for women with preterm prelabour rupture of membranes prior to 37 weeks' gestation for improving pregnancy outcome

BACKGROUND

Delivery after preterm prelabour rupture of the membranes (PPROM) may be initiated soon after PPROM or, alternatively, be delayed. It is unclear which strategy is most beneficial for mothers and their babies.

OBJECTIVES

To assess the effect of planned early birth compared with expectant management for pregnancies complicated with PPROM prior to 37 weeks' gestation.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (May 2009), the Cochrane Central Register of Controlled Trials (The Cochrane Library 2009, Issue 1), MEDLINE (1996 to May 2009), EMBASE (1974 to May 2009), and reference lists of trials and other review articles.

SELECTION CRITERIA

Randomised controlled trials comparing expectant management with early delivery for women with PPROM prior to 37 weeks' gestation. We excluded quasi randomised trials.

DATA COLLECTION AND ANALYSIS

Two review authors independently evaluated trials for inclusion into the review and for methodological quality.

MAIN RESULTS

We included seven trials (690 women) in the review. We identified no difference in the primary outcomes of neonatal sepsis (risk ratio (RR) 1.33, 95% confidence interval (CI) 0.72 to 2.47) or respiratory distress (RR 0.98, 95% CI 0.74 to 1.29). Early delivery increased the incidence of caesarean section (RR 1.51, 95% CI 1.08 to 2.10). There was no difference in the overall perinatal mortality (RR 0.98, 95% CI 0.41 to 2.36), intrauterine deaths (RR 0.26, 95% CI 0.04 to 1.52) or neonatal deaths (RR 1.59, 95% CI 0.61 to 4.16) when comparing early delivery with expectant management. There was no significant difference in measures of neonatal morbidity, including cerebroventricular haemorrhage (RR 1.90 95% CI 0.52 to 6.92), necrotising enterocolitis (RR 0.58, 95% CI 0.08 to 4.08), or duration of neonatal hospitalisation (mean difference (MD) -0.33 days, 95% CI -1.06 to 0.40 days). In assessing maternal outcomes, we found that early delivery increased endometritis (RR 2.32, 95% CI 1.33 to 4.07), but that early delivery had no effect on chorioamnionitis (RR 0.44, 95% CI 0.17 to 1.14). There was a significant reduction of early delivery on the duration of maternal hospital stay (MD -1.13 days, 95% CI -1.75 to -0.51 days).

AUTHORS' CONCLUSIONS

There is insufficient evidence to guide clinical practice on the benefits and harms of immediate delivery compared with expectant management for women with PPROM. To date all of the clinical trials have had methodological weaknesses and have been underpowered to detect meaningful measures of infant and maternal morbidity.

Activin A as a marker of intrauterine infection in women with preterm prelabour rupture of membranes

OBJECTIVE

To assess maternal serum activin A, an early phase response protein in systemic infection, as an early marker of intrauterine infection in women with preterm prelabour rupture of membranes (PPROM).

STUDY DESIGN

A prospective cohort study of women with singleton pregnancies complicated by PPROM at 24 to 34 weeks' gestation. Serum was collected for activin A and cytokine measurements. Activin A was measured using commercial enzyme-linked immunosorbent assay. Cytokines were measured using commercial multiplex assay. Pregnancy outcomes including infection were determined by case-record review.

RESULT

Eighteen women with PPROM were studied, with seven developing intrauterine infection. Serum activin A in women with and without infection did not differ. Peripheral white cell count, interleukin (IL)-6 and IL-10 were higher (P=0.03, 0.05 and 0.009, respectively) and IL-7 lower (P=0.04) 72 h before delivery in women with infection.

CONCLUSION

Activin A is not a clinically useful marker of intrauterine infection in women with PPROM.

Characterization of RAGE, HMGB1, and S100beta in inflammation-induced preterm birth and fetal tissue injury

Immune activation represents an adaptive reaction triggered by both noxious exogenous (microbes) and endogenous [high mobility group box-1 protein (HMGB1), S100 calcium binding proteins] inducers of inflammation. Cell stress or necrosis lead the release of HMGB1 and S100 proteins in the extracellular compartment where they act as damage-associated molecular pattern molecules (or alarmins) by engaging the receptor for advanced glycation end-products (RAGE). Although the biology of RAGE is dictated by the accumulation of damage-associated molecular pattern molecules at sites of tissue injury, the role of RAGE in mediating antenatal fetal injury remains unknown. First, we studied the relationships at birth between the intensity of human fetal inflammation and sRAGE (an endogenous RAGE antagonist), HMGB1, and S100beta protein. We found significantly lower sRAGE in human fetuses that mounted robust inflammatory responses. HMGB1 levels correlated significantly with levels of interleukin-6 and S100beta in fetal circulation. We then evaluated the levels and areas of tissue expression of RAGE, HMGB1, and S100beta in specific organs of mouse fetuses on E16. Using an animal model of endotoxin-induced fetal damage and preterm birth, we determined that inflammation induces a significant change in expression of RAGE and HMGB1, but not S100beta, at sites of tissue damage. Our findings indicate that RAGE and HMGB1 may be important mediators of cellular injury in fetuses delivered in the setting of inflammation-induced preterm birth.

Transient lipopolysaccharide-induced cytokine responses in the maternal serum and amniotic fluid of the guinea pig

OBJECTIVE

The aim of this study was to characterize the pregnant guinea pig cytokine time course following a maternal inflammatory insult.

STUDY DESIGN

Pregnant guinea pigs (n = 34) were injected intraperitoneally with 100 microg/kg lipopolysaccharide (LPS) at 70% gestation and euthanized at 24 hours, 48 hours, or 5 days. Control animals were euthanized at 70% gestation without LPS exposure. Interleukin (IL)-6, IL-1beta, and tumor necrosis factor-alpha (TNF-alpha) were quantified in the maternal serum and amniotic fluid by an enzyme-linked immunosorbent assay.

RESULTS

IL-6 and IL-1beta concentrations were elevated in the maternal serum at 24 hours and returned to control levels by 5 days. In the amniotic fluid, IL-6 peaked at 48 hours and IL-1beta at 24 hours. TNF-alpha levels were not significantly increased.

CONCLUSION

Maternal intraperitoneal LPS injection produces transient increases in cytokine concentrations in the maternal serum and amniotic fluid within 5 days, further implicating the cytokines as mediators of fetal white matter damage.

Tumour Necrosis Factor-alpha Converting Enzyme in Human Gestational Tissues from Pregnancies Complicated by Chorioamnionitis

Chorioamnionitis increases the risk of preterm labour and is associated with adverse neonatal outcomes including cerebral palsy. Tumour necrosis factor-alpha (TNF-alpha) derived from the gestational tissues (placenta, fetal membranes and maternal decidua) is thought to play a pivotal role in the induction of cytokine response in chorioamnionitis. Tumour necrosis factor-alpha converting enzyme (TACE) is essential for the release of TNF-alpha. Our aim was to determine whether the expression of TACE is increased in human gestational tissues from pregnancies complicated by chorioamnionitis, and whether lipopolysaccharide (LPS) causes increased expression of TACE in the human gestational tissues in vitro. The immunostaining of TACE was generally more intense, in particular in the syncytiotrophoblast and stromal cells, in villous samples from pregnancies complicated by chorioamnionitis than those from normal pregnancies. Increased immunoreactivity of TACE was also noted in the amnion and choriodecidua. In parallel, there was an increased infiltration of monocytes/macrophages within the villous stroma and choriodecidua. As a complement to our in vivo findings, LPS significantly increased the levels of mRNA and protein of TACE in a dose-dependent response in villous and fetal membrane explant cultures. Together, our results imply a potential role of TACE in the pathogenesis of chorioamnionitis.

Protocol for the immediate delivery versus expectant care of women with preterm prelabour rupture of the membranes close to term (PPROMT) Trial [ISRCTN44485060]

Background

Preterm prelabour rupture of membranes (PPROM) complicates up to 2% of all pregnancies and is the cause of 40% of all preterm births. The optimal management of women with PPROM prior to 37 weeks, is not known. Furthermore, diversity in current clinical practice suggests uncertainty about the appropriate clinical management.

There are two options for managing PPROM, expectant management (a wait and see approach) or early planned birth. Infection is the main risk for women in which management is expectant. This risk need to be balanced against the risk of iatrogenic prematurity if early delivery is planned. The different treatment options may also have different health care costs. Expectant management results in prolonged antenatal hospitalisation while planned early delivery may necessitate intensive care of the neonate for problems associated with prematurity.

Methods/Design

We aim to evaluate the effectiveness of early planned birth compared with expectant management for women with PPROM between 34 weeks and 36⁶ weeks gestation, in a randomised controlled trial. A secondary aim is a cost analysis to establish the economic impact of the two treatment options and establish the treatment preferences of women with PPROM close to term.

The early planned birth group will be delivered within 24 hours according to local management protocols. In the expectant management group birth will occur after spontaneous labour, at term or when the attending clinician feels that birth is indicated according to usual care. Approximately 1812 women with PPROM at 34–36⁶ weeks gestation will be recruited for the trial.

The primary outcome of the study is neonatal sepsis. Secondary infant outcomes include respiratory distress, perinatal mortality, neonatal intensive care unit admission, assisted ventilation and early infant development. Secondary maternal outcomes include chorioamnionitis, postpartum infection treated with antibiotics, antepartum haemorrhage, induction of labour, mode of delivery, maternal satisfaction with care, duration of hospitalisation, and maternal wellbeing at four months postpartum.

Discussion

This trial will provide evidence on the optimal care for women with PPROM close to term (34–37 weeks gestation). Consideration of both the clinical and economic sequelae of the management of PPROM will enable informed decision making and guideline development.

The association between inherited cytokine polymorphisms and cerebral palsy

OBJECTIVE

The purpose of this study was to investigate associations between inherited cytokine polymorphisms and cerebral palsy.

STUDY DESIGN

This was a case-control study that used DNA from the newborn infant screening cards of 443 white infants with cerebral palsy and 883 white control infants to test for the following cytokine polymorphisms: tumor necrosis factor-alpha-308, mannose-binding lectin-221, and 3 polymorphisms in exon-1 of the mannose-binding lectin gene at codon-52, -54, and -57.

RESULTS

At all gestational ages mannose-binding lectin codon-54 increased the risk of the development of diplegia (homozygous or heterozygous odds ratio, 1.55; 95% CI, 1.03-2.32). For babies who were born at term, the risk of the development of quadriplegia was associated with heterozygous tumor necrosis factor-alpha (odds ratio, 1.82; 95% CI, 1.04-3.15), and mannose-binding lectin codon-54 was associated with diplegia (homozygous or heterozygous odds ratio, 2.12; 95% CI, 1.10-4.05). The presence of any polymorphism in mannose-binding lectin exon-1 at term approximately doubled the risk of the development of diplegia (odds ratio, 1.94; 95% CI, 1.05-3.62). Homozygous or heterozygous tumor necrosis factor-alpha was associated with hemiplegia for babies who were born at <32 weeks of gestation (odds ratio, 2.38; 95% CI, 1.02-5.58). Overall, the presence of any cytokine polymorphism was associated with cerebral palsy (odds ratio, 1.37; 95% CI, 1.02-1.84).

CONCLUSION

Carriage of polymorphisms in the tumor necrosis factor-alpha and mannose-binding lectin genes are associated with an increased risk of cerebral palsy.

Preterm prelabour rupture of the membranes: a survey of current practice

BACKGROUND

Preterm prelabour rupture of the membranes (PPROM) complicates 1-2% of all pregnancies. Risks of remaining in utero need to be balanced against the risks of iatrogenic prematurity if early birth is planned.

AIMS

To assess and further define the current management of women with pregnancies complicated with PPROM in Australia.

METHODS

A mail out questionnaire was sent to all Australian Members and Fellows of the Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG).

RESULTS

There were 731 responses from RANZCOG Fellows and Members. Corticosteroids were used routinely in the setting of PPROM by 99% (95% confidence intervals (CI) 98.4-100.0%) of obstetricians. Tocolysis was used commonly by 75% (95% CI 98.4-100.0%). Antibiotics are also used routinely by 63% (95% CI 58.8-67.3%) of Australian obstetricians. For women presenting with PPROM less than 34 weeks' gestation 56% (95% CI 48.1-60.0%) of obstetricians would plan to deliver these women prior to term, while for women presenting with PPROM greater than 34 weeks' gestation 50% (95% CI 46.0-54.8%) would offer delivery to such women prior to term.

CONCLUSIONS

There is significant variation in clinical practice in the management of women who present with PPROM in Australia. There is little consensus regarding the optimal timing of delivery for babies of women with pregnancies complicated with PPROM. The present survey supports the need and feasibility of a randomised controlled trial to assess the appropriate gestation at which to deliver women with PPROM near to term.

Cervical incompetence and the role of emergency cerclage

OBJECTIVE

To evaluate the role of emergency cerclage for women who present with a dilated external cervical os and bulging or "hour-glassing" membranes. We examined overall experiences at Kingston General Hospital (KGH) from 2000 to 2004 and conducted a literature review for the period January 1, 1995, to December 31, 2004.

METHODS

A search for cerclages placed by operators in Kingston revealed 12 pregnancies in the period between 2000 and 2004. We reviewed the charts for these women and for their infants. We conducted a literature review, using the terms "cerclage," "cervical," "emergent or emergency cerclage," "rescue cerclage," and "incompetent cervix," using an OVID interface to access MEDLINE records. We excluded articles in which the diagnosis of cervical incompetence was made using ultrasound, because its predictive value has not been shown in randomized trials. The most recent review of this type was carried out in 1995; since then, an additional 24 articles have been published that met our inclusion and exclusion criteria.

RESULTS

The average time between cerclage placement and delivery at KGH was 7 weeks, which allowed for 10 of 13 infants (one twin pregnancy) to be born at 28 weeks or later. Three infants were born weighing under 1 kg; the 10 remaining infants weighed over 1 kg. Histological data are available for 12 placentas of the 13 infants delivered; 7 infants had a histological diagnosis of chorioamnionitis; none of the blood cultures from any of the infants post-delivery revealed septicemia. The literature review identified 638 women. Where reported, the average prolongation of the pregnancy was 7 weeks plus 1 day. This allowed for 60% of infants (range 26% to 80%) to be born after 28 weeks, with an average neonatal survival of over 70% (range 47.2% to 96%). Preterm premature rupture of membranes complicated an average of 29% of pregnancies (range 1% to 58%), and chorioamnionitis was reported in 5% to 80% of pregnancies.

CONCLUSIONS

The KGH data collected and the data available in the literature suggest that emergency cerclage, under ideal circumstances, can significantly prolong pregnancy and increase the chance of viable pregnancy outcome. However, in counselling women about the potential therapeutic benefit of emergency cerclage, the increased risk of chorioamnionitis and its associated risk of fetal inflammatory brain injury, as well as the risk of extending a pregnancy from pre-viability to severe prematurity, should be discussed. A longer-term follow-up than has been carried out here is required for better elucidation of the effect of chorioamnionitis on those infants in childhood and beyond.

Prevalence, Management, and Outcomes of Preterm Prelabour Rupture of the Membranes of Women in Canada

OBJECTIVES

To determine the prevalence of preterm prelabour rupture of the membranes (PPROM) at Canadian university-affiliated perinatal referral centres, to assess the different management strategies, and to review neonatal outcomes.

METHODS

Twelve Canadian university-affiliated perinatal referral centres provided information on their management of PPROM, and 9 participated in data collection to determine prevalence. All women presenting with PPROM during a 2-week period were observed until delivery, and obstetric and neonatal outcome data were subsequently obtained. The total number of deliveries in each centre was recorded for the same time period. We also determined the incidence of PPROM and the neonatal outcome for all women presenting with PPROM at the Kingston General Hospital from January 1999 to December 2001 by retrospective chart review.

RESULTS

In the 9 academic centres, 27 women (1 with a twin pregnancy) presented with PPROM during the 2-week period. There were 1168 deliveries during the same time period, giving a prevalence of PPROM of 2.3%. Overall, 53% of placentas submitted for histopathology after PPROM demonstrated evidence of chorioamnionitis. In the retrospective chart review, we found 153 cases of confirmed PPROM from January 1999 to December 2001,an incidence of 2.8%. Clinical management in all centres was similar for most women who presented with PPROM prior to 34 weeks' gestation. Management after 34 weeks' gestation varied among the 12 centres, ranging from immediate induction of labour to expectant management and induction at a greater gestational age (GA).

CONCLUSIONS

The increased neonatal morbidity associated with PPROM appears to be inversely related to GA. Increased risk of chorioamnionitis is related to increased time from PPROM to delivery.

Histologic chorioamnionitis and severity of illness in very low birth weight newborns

OBJECTIVE

Estimating the risk of in-hospital mortality in the neonatal intensive care unit provides important information for health care providers, and several neonatal illness severity scores have been developed. Histologic chorioamnionitis (HCA) is a known cause of neonatal morbidity and mortality. To date, the relationship between HCA and neonatal illness severity scores has not been rigorously tested. In this study, the relationships among HCA, initial illness severity, and neonatal outcomes were analyzed in very low birth weight (VLBW) newborns admitted to the neonatal intensive care unit.

DESIGN

Prospective.

SETTING

Neonatal intensive care unit.

PATIENTS

A total of 116 VLBW inborn infants (gestational age, 28.1 +/- 2.82 wks; birth weight, 1009 +/- 312 g) were categorized as HCA-positive (n = 67) and HCA-negative (n = 49).

INTERVENTIONS

Placental histology was performed to identify HCA. Illness severity evaluation included several different neonatal illness severity scores-Clinical Risk Index for Babies (CRIB), CRIB-II, Score for Neonatal Acute Physiology-II (SNAP-II), and Score for Neonatal Acute Physiology Perinatal Extension-II (SNAPPE-II)-as well as the recording of severe morbidity and in-hospital mortality.

MEASUREMENTS AND MAIN RESULTS

HCA-positive VLBW newborns showed significantly lower gestational age (p < .0001) and birth weight (p = .0010), together with higher CRIB, CRIB-II, SNAP-II, and SNAPPE-II scores at admission to the NICU (p </= .0001) and mortality rate (p = .0018) than HCA-negative infants. After adjustment for gender and gestational age in a multivariable logistic regression analysis, HCA was found to be an independent predictor of high illness severity: CRIB > 5 (odds ratio [OR], 21.37; 95% confidence interval [CI], 6.24-73.21); CRIB-II > 10 (OR, 56.17; 95% CI, 6.75-467.2); SNAP-II > 22 (OR, 43.05; 95% CI, 11.9-155.7), and SNAPPE-II > 42 (OR, 48.95; 95% CI, 10.18-235.4) (all p values <.0001).

CONCLUSIONS

Our findings indicate that HCA is a major predictor of morbidity and mortality in VLBW newborns.

Chorioamnionitis increases neonatal morbidity in pregnancies complicated by preterm premature rupture of membranes

OBJECTIVE

To compare morbidities of neonates born to women who developed chorioamnionitis after premature preterm rupture of membranes versus those who did not.

STUDY DESIGN

We reviewed outcomes in singleton pregnancies with confirmed premature preterm rupture of membranes at 24 weeks or beyond that resulted in delivery less than 37 weeks. Management of premature preterm rupture of membranes included the use of antibiotics, betamethasone if less than 32 weeks, and expectant management with induction at 34 weeks or greater. Composite neonatal major and minor morbidity rates were compared between pregnancies complicated by chorioamnionitis and those that were not.

RESULTS

From August 1998 to August 2000, 430 cases of premature preterm rupture of membranes were identified among 6003 deliveries (7.2%). Thirteen percent of women (56/430) with premature preterm rupture of membranes developed chorioamnionitis. The incidence of chorioamnionitis increased significantly with decreasing gestational age. The composite neonatal major morbidity rate was significantly higher in neonates whose mothers developed chorioamnionitis (55%) versus those who did not (18%, P < .0001). In a multiple logistic regression model, chorioamnionitis ( P < .0001), infant gender ( P = .007), latency ( P = .03), and gestational age at delivery ( P < .0001) were significantly associated with composite neonatal morbidity.

CONCLUSION

Neonatal morbidities are significantly higher among pregnancies with premature preterm rupture of membranes complicated by chorioamnionitis when compared with pregnancies that were not.

Preterm Premature Rupture of Membranes: Is There an Optimal Gestational Age for Delivery?

OBJECTIVE

To characterize neonatal and maternal morbidity and mortality rates in pregnancies complicated by preterm premature rupture of membranes (PROM) and determine whether there is an optimal delivery gestational age.

METHODS

We reviewed maternal and neonatal outcomes of women with PROM 24 weeks or more that resulted in delivery at less than 37 weeks at our institution from August 1998 to August 2000. Standardized management included the use of antibiotics, betamethasone at less than 32 weeks, and expectant management until 24 weeks or more. Outcomes evaluated included neonatal mortality, composite major and minor neonatal morbidity, individual major and minor neonatal morbidity rates, maternal infection morbidity, and maternal and neonatal length of stay. Gestational age-specific maternal and neonatal outcomes were compared with a referent group of pregnancies complicated by preterm PROM that delivered between 36 0/7 and 36 6/7 weeks of gestation.

RESULTS

During the study interval, 430 women with preterm PROM were identified. Composite major neonatal morbidity was significantly higher among pregnancies delivered at 33 weeks of gestation or less after preterm PROM as compared with those who delivered at 36 weeks. Composite neonatal minor morbidity was significantly higher among pregnancies delivered at 34 weeks or less after preterm PROM as compared with those who delivered at 36 weeks. However, there was no improvement in the composite major and minor neonatal morbidity rates for those pregnancies delivered beyond 34 weeks of gestation. Both maternal and infant length of stay were significantly longer for cases of preterm PROM delivered at 34 weeks or less as compared with those who delivered at 36 weeks.

CONCLUSION

Our findings suggest that expectant management of women at 34 weeks and beyond is of limited benefit.

Animal models of preterm birth

Preterm birth continues to pose a significant clinical dilemma and contributes to both acute and long-term neonatal morbidity. Despite efforts, the incidence of preterm birth has not decreased, partly because of our lack of understanding of the mechanisms that trigger parturition. Animal models are essential research tools for investigating the pathways that promote preterm parturition and for testing therapeutic interventions. Growing evidence correlates infection or inflammation with preterm birth. Consequently, many investigators have created animal models that reflect these findings. Current models of preterm parturition include diverse species, varying means of inducing an inflammatory or infectious state, and different routes of administration. Although each of these models can advance our knowledge, it is important to understand their advantages, disadvantages and unique characteristics. An understanding of such models will hopefully promote continued research that will ultimately lead to a decrease in preterm birth and an improvement in neonatal outcome.

Development of a guinea pig model of chorioamnionitis and fetal brain injury

OBJECTIVE

The purpose of this study was to develop a guinea pig model of chorioamnionitis to study the mechanisms that lead to fetal brain injury. Study design Pregnant guinea pigs at 70% gestation were inoculated intracervically with 1000 to 2500 colony-forming units of Escherichia coli. Guinea pigs were killed 2 to 3 days after bacterial inoculation. Maternal blood and fetal amniotic fluid samples were analyzed for proinflammatory cytokine tumor necrosis factor-alpha, interleukin-1beta, and interleukin-6 levels with the use of enzyme-linked immunosorbent assay kits. Fetal brains were stained for evidence of cell death with NeuroTacs stain.

RESULTS

Of 34 maternal guinea pigs that were given an intracervical inoculation of E coli, 8 guinea pigs showed microbiologic evidence of chorioamnionitis in the amniotic fluid. Tumor necrosis factor-alpha and interleukin-6 were significantly higher (P<.05) in amniotic fluid samples that were obtained from sows that were subjected to intracervical inoculation with bacteria as compared with control animals (n=6 control maternal animals). These results were observed even if no bacteria were found subsequently on culture of the amniotic fluid from inoculated animals, which indicated that indirect exposure to infectious agents was sufficient to cause an elevated inflammatory response in the fetus. Levels of white matter injury were greater in fetuses that were exposed to bacterial infection in utero, as compared with control animals (P<.05). This result was found in the staining of periventricular and cortical white matter for the immunolabeling of activated caspase 3 and NeuroTacs staining for cells that exhibited evidence of apoptotic cell death (positive stain with evidence of karyorrhexis).

CONCLUSION

Intracervical inoculation with E coli results in chorioamnionitis in guinea pigs that is associated with fetal brain injury.

Cerebral palsy

Cerebral palsy, a range of non-progressive syndromes of posture and motor impairment, is a common cause of disability in childhood. The disorder results from various insults to different areas within the developing nervous system, which partly explains the variability of clinical findings. Management options include physiotherapy, occupational and speech therapy, orthotics, device-assisted modalities, pharmacological intervention, and orthopaedic and neurosurgical procedures. Since 1980, modification of spasticity by means of orally administered drugs, intramuscular chemodenervation agents (alcohol, phenol, botulinum toxin A), intrathecally administered drugs (baclofen), and surgery (neurectomy, rhizotomy) has become more frequent. Family-directed use of holistic approaches for their children with cerebral palsy includes the widespread adoption of complementary and alternative therapies; however, the prevalence of their use and the cost of these options are unknown. Traditional medical techniques (physiotherapy, bracing, and orthopaedic musculoskeletal surgery) remain the mainstay of treatment strategies at this time. This seminar addresses only the musculoskeletal issues associated with cerebral palsy and only indirectly discusses the cognitive, medical, and social issues associated with this diagnosis.

Severe umbilical cord inflammation-a predictor of periventricular leukomalacia in very low birth weight infants

Chorioamnionitis has been associated with periventricular leukomalacia (PVL) in very low birth weight (VLBW) infants. We examined the association between the pathological severity of chorioamnionitis and PVL in VLBW infants. Thirty-four VLBW infants with PVL and 34 control infants matched for gestational age without a diagnosis of PVL or intraventricular hemorrhage were obtained from the Women and Infants' Hospital of Rhode Island's Neonatal Follow-up Clinic database. Placental samples, including the amnion/chorion, chorionic plate, and umbilical cord, were examined microscopically. Statistical analysis included Mantel-Haenszel chi-square, and Student's t-test. Severe inflammation in the umbilical cord was observed in 53% of infants with PVL and 32% without PVL (p<0.05). Severe umbilical cord inflammation is one of the risk factors associated with the development of PVL in VLBW infants.

Changes in neurotrophin levels in umbilical cord blood from infants with different gestational ages and clinical conditions

Apoptotic neuronal loss may be responsible for altered brain development associated with prematurity and perinatal insults. Neurotrophins play crucial roles in protecting neurons from entering or progressing along an apoptotic pathway. The present study examined levels of neurotrophins in human umbilical cord blood from infants at different gestational ages and clinical conditions. We collected 60 samples of cord blood and categorized them accordingly into three gestational age groups: group A (24-28 wk), group B (29-35 wk), and group C (>/=36 wk). Neurotrophin levels were determined by using brain-derived neurotrophic factor (BDNF) and neurotrophin 3 (NT3) ELISA. Clinical data were obtained by medical chart analysis. The BDNF levels were 884 +/- 386, 1421 +/- 616, and 2190 +/- 356 pg/mL in group A, group B, and group C, respectively. Significant differences were found between groups A and B (p = 0.038), groups A and C (p = 0.0001), and groups B and C (p = 0.001). Infants with severe intraventricular hemorrhage had significantly lower cord blood BDNF levels (925 +/- 513 pg/mL) compared with their normal counterparts (1650 +/- 674 pg/mL; p = 0.021). NT3 levels did not show significant change either across gestational ages or with the presence of intraventricular hemorrhage. Cord blood levels of BDNF may reflect the degree of neural maturity in premature infants. Interestingly, when a complete course of antenatal steroids was given, BDNF and NT3 cord blood levels were higher than when no steroid was given. Increased neurotrophins levels may also mediate improved neurodevelopmental outcome in infants who received antenatal steroids.

Temporal and demographic trends in cerebral palsy--fact and fiction

The rate of cerebral palsy has not decreased in developed countries over the past 30 years, despite the widespread use of electronic fetal heart rate monitoring and a 5-fold increase in the cesarean delivery rate over the same period of time. However, neonatal survival has improved during these decades. These observations have lead to the hypothesis that increased survival of premature, neurologically impaired infants may have masked an actual reduction in cerebral palsy among term infants as a result of the use of electronic monitoring and the avoidance of intrapartum asphyxia. A review of the medical literature, as well as a demographic analysis of term and preterm birth rates in the United States, refutes this hypothesis on four grounds. First, cerebral palsy prevalence has been separately analyzed in term infants and shows no change over 30 years. Second, the prevalence of cerebral palsy is the same or lower in underdeveloped countries than in developed nations; in the former, the availability of emergency cesarean delivery based on electronic monitor data is limited or absent. Third, the increase in prevalence of cerebral palsy among low-birth-weight infants and the increase in cesarean sections based on presumed fetal distress were not simultaneous events-the former preceded the latter by a decade. Improved neonatal survival since the 1980s has been associated with a stable or decreasing rate of neurologic impairment and thus could not have obscured improvement from reduced term asphyxia. Finally, compared with the number of infants born by cesarean section for fetal distress, there are simply not enough infants born in the most vulnerable weight groups to make any impact on even a minimal improvement of outcome in the group delivered by cesarean section for presumed fetal distress. Except in rare instances, cerebral palsy is a developmental event that is unpreventable given our current state of technology.

Antenatal causes of cerebral palsy: associations between inherited thrombophilias, viral and bacterial infection, and inherited susceptibility to infection

Cerebral palsy rates of 2 in every 1,000 births have varied little over the last 40 years, despite improvements in obstetric care. In the past, cerebral palsy was thought to be due to poor obstetric care and management; however, epidemiological studies have refuted this, suggesting that there is usually an antenatal timing to the neuropathology of cerebral palsy. There are many known risk factors for cerebral palsy, including multiple gestation, prematurity, and low birth weight. Recently, intrauterine infection, maternal pyrexia, and the presence of thrombophilic disorders (thrombophilia) have been identified as major risk factors for subsequent cerebral palsy. This review examines the links between intrauterine infection, the fetal inflammatory response, and thrombophilia as possible causes of cerebral palsy. The interactions of viral or bacterial infections during pregnancy, normal or abnormal fetal cytokine responses, and hereditary fetal thrombophilias as antenatal causes of the neuropathology of cerebral palsy are now areas of research priority.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians

LEARNING OBJECTIVES

After completion of this article, the reader will be able to describe the condition cerebral palsy, list the risk factors for the development of cerebral palsy, outline the ultrasound findings associated with cerebral palsy, and point out other conditions associated with cerebral palsy.

Therapies administered to mothers at risk for preterm birth and neurodevelopmental outcome in their infants

A decrease in the rate of preterm births and the prevention of prematurity-associated neurodevelopmental morbidity are critical for the reduction of neurodevelopmental disability. Efforts to reduce the overall preterm delivery rate have been unsuccessful. Although progress has been achieved in the prevention of short-term neonatal morbidity over the past several decades, the majority of the improvements have resulted from improved neonatal care. Whether obstetric interventions can improve neurodevelopmental outcome is unknown. The ability to adequately assess obstetric interventions is hampered by the limited number of interventional studies that included long-term outcome assessment. Thus, it is incumbent upon ongoing and future interventional studies to consider long-term outcome assessment as a critical component of the overall evaluation of efficacy of obstetric therapies.

Proinflammatory cytokines: a link between chorioamnionitis and fetal brain injury

OBJECTIVE

To review the etiology of impaired fetal neurodevelopment - in particular, the relationship between chorioamnionitis, cytokines, and cerebral palsy.

DATA SOURCES

A MEDLINE search was performed for all clinical and basic science studies published in the English literature from 1966 to 2002. Key words or phrases used were chorioamnionitis, cerebral palsy, fetal brain damage, fetal CNS injury, infection in pregnancy, proinflammatory cytokines in pregnancy, proinflammatory cytokines in infection, and preterm labour or birth. All relevant human and animal studies were included.

STUDY SELECTION

Fetal brain injury remains a major cause of lifelong morbidity, incurring significant societal and health care costs. It has been postulated that chorioamnionitis stimulates maternal/fetal proinflammatory cytokine release, which is damaging to the developing fetal nervous system. Elevated cytokine concentrations may interfere with glial cell development and proliferation in the late second trimester of pregnancy, when the central nervous system is most vulnerable. Increasing numbers of epidemiological and basic science studies found through MEDLINE searches support this hypothesis. Treatment options aimed at etiologic factors may lead to improved neurodevelopmental outcomes.

CONCLUSIONS

Clearly, some relationship exists between chorioamnionitis, cytokines, and the development of cerebral palsy, but the severity and duration of exposure required to produce fetal damage remains unknown. Future research addressing these issues may aid in clinical decision-making. As well, the elucidation of mechanisms of cytokine action may aid in early treatment options to prevent or limit development of fetal brain injury.

Periventricular leukomalacia, inflammation and white matter lesions within the developing nervous system

Periventricular leukomalacia (PVL) occurring in premature infants, represents a major precursor for neurological and intellectual impairment, and cerebral palsy in later life. The disorder is characterized by multifocal areas of necrosis found deep in the cortical white matter, which are often symmetrical and occur adjacent to the lateral ventricles. There is no known cure for PVL. Factors predisposing to PVL include birth trauma, asphyxia and respiratory failure, cardiopulmonary defects, premature birth/low birthweight, associated immature cerebrovascular development and lack of appropriate autoregulation of cerebral blood flow in response to hypoxic-ischemic insults. The intrinsic vulnerability of oligodendrocyte precursors is considered as central to the pathogenesis of PVL. These cells are susceptible to a variety of injurious stimuli including free radicals and excitotoxicity induced by hypoxic-ischemic injury (resulting from cerebral hypoperfusion), lack of trophic stimuli, as well as secondary associated events involving microglial and astrocytic activation and the release of pro-inflammatory cytokines TNF-alpha and IL-6. It is yet unclear whether activated astrocytes and microglia act as principal participants in the development of PVL lesions, or whether they are representatives of an incidental pathological response directed towards repair of tissue injury in PVL. Nevertheless, the accumulated evidence points to a pathological contribution of microglia towards damage. The topography of lesions in PVL most likely reflects a combination of the relatively immature cerebrovasculature together with a failure in perfusion and/or hypoxia during the greatest period of vulnerability occurring around mid-to-late gestation. Mechanisms underlying the pathogenesis of PVL have so far been related to prenatal ischemic injury to the brain initiated within the third trimester, which result in global cognitive and developmental delay and motor disturbances. Over the past few years, several epidemiological and experimental studies have implicated intrauterine infection and chorioamnionitis as causative in the pathogenesis of PVL. In particular, recent investigations have shown that inflammatory responses in the fetus and neonate can contribute towards neonatal brain injury and development-related disabilities including cerebral palsy. This review presents current concepts on the pathogenesis of PVL and emphasizes the increasing evidence for an inflammatory pathogenic component to this disorder, either resulting from hypoxic-ischemic injury or from infection. These findings provide the basis for clinical approaches targeted at protecting the premature brain from inflammatory damage, which may prove beneficial for treating PVL, if identified early in pathogenesis.