Risk factors for early intraventricular hemorrhage in low birth weight infants

Pharmacological neuroprotection and clinical trials of novel therapies for neonatal peri-intraventricular hemorrhage: a comprehensive review

Peri-intraventricular hemorrhage (PIVH) is a serious condition for preterm infants, caused by traumatic or spontaneous rupture of the germinal matrix (GM) capillary network in the cerebral ventricles. It is a common source of morbidity and mortality in neonates, and risk correlates with earlier delivery, low birth weight, maternal-fetal infection, and vital sign derangements, among others. PIVH typically occurs in the first 72 h of life, and symptoms, when present, manifest most commonly within the first week of life. Prevention remains the primary goal in management, predominantly via prolonging of gestation. Current therapy protocols are center-dependent without consistent consensus guidelines, but infant positioning, homeostatic stabilization, and neuroprotection offer potential options. In this update of pharmacologic neuroprotective therapies for PIVH, we highlight commonly utilized therapies and review the investigative literature. Further multi-institutional clinical trials and basic research studies are required.

Intracranial Hemorrhage and 2-Year Neurodevelopmental Outcomes in Infants Born Extremely Preterm

OBJECTIVES

To determine the incidence, timing, progression, and risk factors for intracranial hemorrhage (ICH) in infants 24^0/7 to 27^6/7 weeks of gestational age and to characterize the association between ICH and death or neurodevelopmental impairment (NDI) at 2 years of corrected age.

STUDY DESIGN

Infants enrolled in the Preterm Erythropoietin Neuroprotection Trial had serial cranial ultrasound scans performed on day 1, day 7-9, and 36 weeks of postmenstrual age to evaluate ICH. Potential risk factors for development of ICH were examined. Outcomes included death or severe NDI as well as Bayley Scales of Infant and Toddler Development, 3rd Edition, at 2 years of corrected age.

RESULTS

ICH was identified in 38% (n = 339) of 883 enrolled infants. Multiple gestation and cesarean delivery reduced the risk of any ICH on day 1. Risk factors for development of bilateral Grade 2, Grade 3, or Grade 4 ICH at day 7-9 included any ICH at day 1; 2 or more doses of prenatal steroids decreased risk. Bilateral Grade 2, Grade 3, or Grade 4 ICH at 36 weeks were associated with previous ICH at day 7-9. Bilateral Grade 2, any Grade 3, and any Grade 4 ICH at 7-9 days or 36 weeks of postmenstrual age were associated with increased risk of death or severe NDI and lower Bayley Scales of Infant and Toddler Development, 3rd Edition, scores.

CONCLUSIONS

Risk factors for ICH varied by timing of bleed. Bilateral and increasing grade of ICH were associated with death or NDI in infants born extremely preterm.

Growth trajectory of preterm small-for-gestational-age neonates

AIM

To assess the growth trajectory of preterm small-for-gestational-age (SGA) neonates compared to preterm non-small-for-gestational age neonates in the neonatal intensive care unit and special care nursery.

METHODS

We conducted a retrospective cohort study at a large tertiary hospital in Victoria, Australia, examining neonates ≤34 weeks' gestation admitted to the neonatal intensive care unit or special care nursery between 2013 and 2017. We categorized neonates according to their birth weight centile: <10th centile (small-for-gestational age) and ≥10th centile (non-small-for-gestational age). Growth trajectory was tracked based on serial weights obtained in the neonatal intensive care unit and special care nursery, using z-scores derived from Fenton preterm growth charts. Our primary outcome was the change in weight z-score from birth to discharge from neonatal intensive care unit or special care nursery.

RESULTS

Of the 910 babies included, 88 were small-for-gestational age and 822 were appropriate-for gestational age. Both groups had a reduction in their weight z-score; however, SGA babies had a significantly smaller reduction (-0.62 SD compared to -0.85 SD, p < .0001). Small-for-gestational-age neonates were four times more likely to experience an increase in their weight z-score across their admission compared to neonates who were not small-for-gestational age (OR 4.04, 95% CI 2.23-7.48, p < .0001). Small-for-gestational-age neonates had an increased median length of stay, increased incidence of necrotizing enterocolitis but a reduced incidence of intraventricular hemorrhage.

CONCLUSIONS

Preterm SGA babies experience a smaller reduction in their weight trajectory compared to their appropriately grown counterparts in the neonatal intensive care unit or special care nursery.

Placental pathology and intraventricular hemorrhage in preterm and small for gestational age infants

OBJECTIVE

The aim of this study was to examine the relationship between chorioamnionitis and vascular malperfusion on placental pathology and intraventricular hemorrhage (IVH) in premature and small for gestational age (SGA) infants.

STUDY DESIGN

A retrospective analysis of 263 infants ≤34 weeks gestation or ≤1800 g and their mothers was conducted by chart review for placental pathology and clinical data from 2014 to 2018. Unadjusted and adjusted odds ratios (OR) for the association of placental pathology with IVH were calculated.

RESULT

Unadjusted OR showed an association between acute chorioamnionitis and IVH, but logistic regression analysis showed a non-significant adjusted OR between acute or chronic chorioamnionitis with IVH. Maternal vascular malperfusion was significantly associated with increased IVH when controlling for confounders.

CONCLUSION

Placental maternal vascular malperfusion is associated with the development of IVH in premature and SGA infants when controlling for other confounders.

Caesarean section and neonatal survival and neurodevelopmental impairments in preterm singleton neonates

Introduction

Evidence is lacking regarding the benefit of caesarean section (CS) for long-term neurodevelopmental outcomes in singleton preterm neonates. Therefore, uncertainty remains regarding obstetrical best practice in the delivery of premature neonates.

Objective

Our objective was to determine the association between the mode of delivery and neurodevelopmental outcomes in preterm singleton neonates who were delivered by vaginal route (VR), CS with labour (CS-L), or CS without labour (CS-NL).

Methods

Singleton neonates of less than 29 weeks' gestation born January 1995 through December 2010 and admitted to our NICU and then assessed at neonatal follow-up clinic were studied. The primary outcome was neurodevelopmental impairment (NDI) defined as cerebral palsy, cognitive delay, major or minor visual impairment, or hearing impairment or deafness at 36 months' corrected age.

Results

In this retrospective cohort study of 1,452 neonates, 1,000 were eligible for the study and 881 (88.1%) were available for follow-up. There was no significant difference in mortality between VR group, CS-L group, and CS-NL group. At 3 years, there was no significant difference between the three groups in terms of NDI. The odds of composite outcome of mortality or NDI for neonates born via CS-NL versus VR, and CS-L versus VR were 0.90 (95% confidence interval [CI]: 0.59 to 1.37) and 1.08 (95% CI: 0.72 to 1.61), respectively. Propensity score-based matched-pair analyses did not show a significant association between the composite outcome and CS with or without labour.

Conclusions

CS was not associated with increased survival or decreased risk of NDI in premature singleton neonates born at less than 29 weeks' gestation.

Unfavorable influence of prematurity on the neonatal prognostic of small for gestational age fetuses

Vascular stress at the level of the uterus-placental unit, with chronic placental ischemia, results in intrauterine growth restriction. Expectation management can be used, when the situation allows, in cases of compensated intrauterine growth restriction. The aim of the present study was to evaluate the neonatal prognosis of preterm births with and without growth restriction and term births with growth restriction in order to improve decisional accuracy regarding the termination of pregnancy. The frequency of term birth infants with low birth weight for gestational age was ~2%. The male sex, predominated only in the group of premature infants with normal weight for the gestational age. The highest frequency of neonatal complications studied occurred in the group of preterm neonates small for gestational age (SGA) with statistical significance obtained for cardiovascular arrest acute respiratory failure, ulcer-necrotic enterocolitis, respiratory distress, cerebral edema, intraventricular hemorrhage, cerebral hemorrhage, pulmonary hemorrhage, neonatal infection, hypoglycemia, retinopathy, anemia, hemorrhagic disease, disseminated intravascular coagulation, disease of hyaline membranes, neonatal sepsis, need for intensive neonatal therapy and death. In conclusion, immediate neonatal adaptation of SGA preterm neonates is more deficient than for preterm neonates with appropriate weight for gestational age; the adaptation of preterm neonates, in turn, is more deficient than term newborns with intrauterine growth restriction. The term newborns with intrauterine growth restriction have a neonatal adaptation comparable to that of the term newborns with weight corresponding to the gestational age.

Intraventricular hemorrhage and posthemorrhagic hydrocephalus in preterm infants: diagnosis, classification, and treatment options

PURPOSE

Intraventricular hemorrhage is the most important adverse neurologic event for preterm and very low weight birth infants in the neonatal period. This pathology can lead to various delays in motor, language, and cognition development. The aim of this article is to give an overview of the knowledge in diagnosis, classification, and treatment options of this pathology.

METHOD

A systematic review has been made.

RESULTS

The cranial ultrasound can be used to identify the hemorrhage and grade it according to the modified Papile grading system. There is no standardized protocol of intervention as there are controversial results on which of the temporizing neurosurgical procedures is best and about the appropriate parameters to consider a conversion to ventriculoperitoneal shunt. However, it has been established that the most important prognosis factor is the involvement and damage of the white matter.

CONCLUSION

More evidence is required to create a standardized protocol that can ensure the best possible outcome for these patients.

Long-term outcomes of saline boluses in very preterm infants

BACKGROUND

Normal saline bolus is commonly used in clinical practice for treating hypotension in very preterm infants during resuscitation at an early age despite the paucity of high quality evidence supporting this practice.

OBJECTIVES

To determine the effects of early (<7 days after birth) saline boluses given to very preterm infant (VPI) from 23 to 31 weeks GA.

METHOD

This is a population-based cohort analysis of the use of normal saline boluses given to VPI. The outcomes were extracted from the Perinatal Follow-Up Program Database which included all VPI from Halifax County admitted to the NICU at the IWK Health Centre, Halifax, Nova Scotia, Canada between January 2006 to December 2010. We excluded infants with major congenital anomalies and those not offered resuscitation in the delivery room. Our primary outcome was the composite of death or disability by 18-36 months while secondary outcomes were neonatal death, BPD, CP, IVH, PVL, ROP, BSITD III (Bayley Scales of Infant and Toddler Development®, Third Edition) Cognitive, Motor and Language score.

RESULTS

Death or disability in those who received saline bolus occurred in 15 (53.6%) compared with 9 (32.1%) in non saline group. Significantly higher rates of CP (p = 0.04), lower scores on the BSITDIII for motor (p = 0.04) and language scales (p = 0.03) were noted for infants who received saline boluses. Cognitive scores approached significance (p = 0.05) with lower scores in the saline bolus group.

CONCLUSION

Significant differences were found between the two groups in terms of long term neurodevelopmental outcome and one of the short-term outcome (i.e. BPD). Given the limitations of this retrospective study and the small sample size, a larger cohort from Canadian Neonatal Network database is warranted to evaluate the effects of using normal saline boluses during early life on neurodevelopmental.

Successful implementation of an intracranial hemorrhage (ICH) bundle in reducing severe ICH: a quality improvement project

OBJECTIVE

Our specific, measurable, attainable, relevant, and time-limited (SMART) aim was to reduce the incidence of severe intracranial hemorrhage (ICH) among preterm infants born <30 weeks' gestation from a baseline of 24% (January 2012-December 2013) to a long-term average of 11% by December 2015.

STUDY DESIGN

We instituted an ICH bundle consisting of elements of the "golden hour" (delayed cord clamping, optimized cardiopulmonary resuscitation, improved thermoregulation) and provision of cluster care in the neonatal intensive care unit (NICU). We identified key drivers to achieve our SMART aims, and implemented quality improvement (QI) cycles: initiation of the ICH bundle, education of NICU staff, and emphasis on sustained adherence. We excluded infants born outside our facility and those with congenital anomalies.

RESULTS

Using statistical process control analysis (p-chart), the ICH bundle was associated with successful reduction in severe ICH (grade 3-4) in our NICU from a prebundle rate of 24% (January 2012-December 2013) to a sustained reduction over the next 4 years to an average rate of 9.7% by December 2017. Results during 2016-2017 showed a sustained improvement beyond the goal for 2014-2015. Over the same interval, there was improvement in admission temperatures [median 36.1 °C (interquartile range: 35.3-36.7 °C) vs. 37.1 °C (36.8-37.5 °C), p < 0.01] and a decrease in mortality rate [pre: 16/117 (14%) vs. post: 16/281 (6%), P < 0.01].

CONCLUSION

Our multidisciplinary QI initiative decreased severe ICH in our institution from a baseline rate of 24% to a lower rate of 9.7% over the ensuing 4 years. Intensive focus on sustained implementation of an ICH bundle protocol consisting of improved delivery room management, thermoregulation, and clustered care in the NICU was temporally associated with a clinically significant reduction in severe ICH.

Features of serial cranial ultrasound detected neuropathology in very preterm infants

BACKGROUND

The purpose of this study was to identify the pattern and factors associated with changes in cranial ultrasound (CUS) -detected findings in infants born at or less than 28 weeks of gestation.

METHODS

We compared readings of CUS performed at the end of the first week of life and at 4-5 weeks of age. Alteration of CUS findings was classified as: (i) unchanged, if no deviation was detected (Group 1); (ii) worsening, if there were new findings (Group 2); and (iii) improvement, if there was normalization or reduction in severity (Group 3). Descriptive statistics, multivariate controlled logistic regression, and kappa (k) statistics with 95% Confidence Interval (95% CI) were reported.

RESULTS

Among 510 studied infants, 82.3% (95% CI 78.8-85.4) were in Group 1, 10.0% (95% CI 7.7-12.9) in Group 2, and 7.7% (95% CI 5.7-10.3) in Group 3. Overall agreement between the two scans was moderate (k 0.62; 95% CI 0.55-0.69). Worsening of CUS findings was associated with neonatal morbidities independently from gestational age and birth weight. The probability for worsening of CUS findings was higher in infants with an initial diagnosis of intraventricular hemorrhage (IVH) grade 2, than in those reported as no pathology/IVH grade 1 (Odds Ratio 5.79; 95% CI 2.42-13.91) or IVH grade 3-4 (Odds Ratio 3.81; 95% CI 1.10-13.21).

CONCLUSIONS

In very preterm born infants, the initial CUS findings in combination with neonatal morbidities can help predict the brain lesions that are seen at the end of the first month of life and could be useful in their clinical management.

Prediction of intraventricular haemorrhage in preterm infants using time series analysis of blood pressure and respiratory signals

Despite the decline in mortality rates of extremely preterm infants, intraventricular haemorrhage (IVH) remains common in survivors. The need for resuscitation and cardiorespiratory management, particularly within the first 24 hours of life, are important factors in the incidence and timing of IVH. Variability analyses of heart rate and blood pressure data has demonstrated potential approaches to predictive monitoring. In this study, we investigated the early identification of infants at a high risk of developing IVH, using time series analysis of blood pressure and respiratory data. We also explore approaches to improving model performance, such as the inclusion of multiple variables and signal pre-processing to enhance the results from detrended fluctuation analysis. Of the models we evaluated, the highest area under receiver-operator characteristic curve (5th, 95th percentile) achieved was 0.921 (0.82, 1.00) by mean diastolic blood pressure and the long-term scaling exponent of pulse interval (PI α₂), exhibiting a sensitivity of >90% at a specificity of 75%. Following evaluation in a larger population, our approach may be useful in predictive monitoring to identify infants at high risk of developing IVH, offering caregivers more time to adjust intensive care treatment.

Perinatal management: What has been learned through the network?

The Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network (NRN) has examined the effects of various obstetrical perinatal interventions and neonatal delivery room practices on the newborn with particular focus on those born preterm. Studies exploring the effects and safety of various antepartum maternal medications and the effects of the route and timing of delivery are examined. The NRN has contributed key studies to the evidence base for the International Liaison Committee on Resuscitation neonatal resuscitation guidelines. These studies are reviewed including research on timing of cord clamping, the importance of maintaining euthermia immediately after birth, delivery room ventilation strategies, outcomes following delivery room cardiopulmonary resuscitation, and the effects of prolonged resuscitation efforts. In addition, the NRN's detailed outcome data at the lowest gestational ages have greatly influenced on how providers counsel families regarding the appropriateness of resuscitation efforts at the lowest gestational ages.

Safety of vaginal delivery in very low birthweight vertex singletons: a meta-analysis

OBJECTIVE

The objective of this study is to assess the safety of vaginal delivery in VLBW singletons in the vertex presentation.

METHODS

MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Web of Science databases were searched for studies on mode of delivery and neonatal outcome in VLBW singletons in the vertex presentation. A total of 28 studies met our inclusion criteria.

RESULTS

Vaginal delivery was not associated with an increase in overall neonatal mortality compared with cesarean delivery (OR 0.87, 95% CI 0.72-1.04). Vaginal delivery was associated with a significant decrease in mortality for the 1250-1500 g birthweight category (OR 0.57, 95% CI 0.36-0.92), while an increase in mortality in the 500-750 g category was not significant (OR 1.5, 95% CI 0.86-2.61). Severe intraventricular hemorrhage (IVH) was not associated with mode of delivery (OR 1.05, 95% CI 0.85-1.29), but the only two high quality study that assessed IVH of all grades found an increase in risk for IVH in vaginal delivery (OR 1.33, 95% CI 1.16-1.51).

CONCLUSIONS

Vaginal delivery does not appear to increase the risk for neonatal mortality. However, current available data on neonatal morbidity are limited. More high-quality studies are needed to assess the association between mode of delivery and neonatal morbidity.

Mode of delivery at periviability and early childhood neurodevelopment

OBJECTIVE

Little is known regarding the impact of mode of delivery in the periviable period. Even less is understood regarding the effect of mode of delivery on neurodevelopment. Our objective is to determine if the mode of delivery at time of periviability impacts Bayley II scores at 2 years of age.

STUDY DESIGN

This is a secondary analysis of a randomized, controlled trial of magnesium sulfate for the prevention of cerebral palsy, a multicenter trial where women at imminent risk for delivery were assigned to receive magnesium sulfate or placebo. For this secondary analysis we included nonanomalous singleton gestations delivered between 23 4/7 and 25 6/7 weeks. We excluded women with missing exposure or outcome data. The primary exposure of interest was mode of delivery. The primary outcome was Bayley II scores <70 (mental and motor) at 2 years of age. Log binomial regression was used to control for possible confounders including gestational age at delivery, presentation at time of delivery, chorioamnionitis, years of maternal education, maternal body mass index, and original study treatment group.

RESULTS

A total of 158 women met inclusion criteria. In all, 91 had a vaginal delivery and 67 had a cesarean delivery. Exposure to magnesium sulfate, maternal education, chorioamnionitis, years of maternal education, and maternal body mass index were similar in both groups. There was no difference in either mental or motor Bayley II scores <70 or <85 by mode of delivery in either univariable or multivariable analysis.

CONCLUSION

There is no detectable difference in Bayley II scores between mode of delivery at time of periviability. This adds to the literature supporting obstetric indications dictating mode of delivery at this gestational age.

Mode of delivery of twin gestation with very low birthweight: is vaginal delivery safe?

OBJECTIVE

The purpose of this study was to determine whether planned vaginal delivery is associated with increased risk of perinatal death and morbidity in twin pregnancies that are complicated by a very low birthweight of the second twin.

STUDY DESIGN

We conducted a retrospective cohort study of twin pregnancies in which the second twin's birthweight was ≤1500 g. One hundred ninety-three twin gestations met the study criteria; patients were classified into 2 groups according to the planned mode of delivery: (1) cesarean delivery (n = 142) and (2) vaginal delivery (n = 51). In the vaginal delivery group, 21 pairs were in cephalic-cephalic presentation at the time of delivery; 28 pairs were cephalic-noncephalic, and 2 pairs were noncephalic-noncephalic. Composite adverse neonatal outcome was defined as the presence of neonatal death, respiratory distress syndrome, sepsis, necrotizing enterocolitis, or intraventricular hemorrhage grade 3-4.

RESULTS

Trial of vaginal delivery was successful for both twins in 90.5% of cephalic-cephalic twins and 96.4% in cephalic-noncephalic twins. The rate of intraventricular hemorrhage was significantly higher in the vaginal delivery group (29.4% vs 8.5%, respectively; P = .013; adjusted odds ratio [OR], 3.65; 95% confidence interval [CI], 1.32-10.1). The increased risk of intraventricular hemorrhage in the vaginal delivery groups was evident in both twin A (17.6% vs 7.0%; P = .029) and twin B (15.7% vs 4.9%; P = .014); however, these differences were not significant after adjustment for possible confounders (twin A: adjusted OR, 1.79; 95% CI, 0.58-5.55; twin B: adjusted OR, 2.13; 95% CI, 0.63-7.25). In addition, subgroup analysis revealed that both cephalic-cephalic and cephalic-noncephalic twins who were delivered vaginally had increased risk for intraventricular hemorrhage. There were no significant differences between the cesarean and vaginal delivery groups in the rates of Apgar score <7 at 5 minutes, arterial cord pH <7.1, composite adverse neonatal outcome, and neonatal mortality rate. However, the rate of respiratory distress syndrome was significantly lower in the vaginal delivery group (66.7% vs 69%; P = .042; OR, 0.34; 95% CI, 0.12-0.96).

CONCLUSION

Vaginal delivery of very low birthweight twins is associated with an increased risk of intraventricular hemorrhage, regardless of presentation. Because of the small sample size and the retrospective cohort design, large prospective randomized studies are needed.

A Systematic Review and Meta-analysis of the Timing of Early Intraventricular Hemorrhage in Preterm Neonates: Clinical and Research Implications

A considerable number of intraventricular hemorrhages (IVH) occur within the first hours of life (HOL). Temporality between IVH and its antecedents as well as a consistent definition of "early IVH" is lacking in a large and growing body of literature. We performed a systematic review of prospective studies that reported onset of IVH in preterm neonates within the first HOL and afterwards. The English literature was searched using three databases up to March 2013. Four timing periods of IVH can be compared in 16 identified studies: 0-6; 7-12; 13-24; after 24 HOL. The 0-6 and after 24 HOL were the major modes of IVH timing. Pooled IVH proportions were estimated through a meta-analysis of studies that were conducted after antenatal steroid and surfactant era. In neonates weighing ≤1500 g at birth: 48% of IVH (95% CI: 42-58%, 5 studies, 279 IVH cases) occurred during 0-6 HOL and 38% (95% CI: 19-57%, 4 studies, 241 IVH cases) after 24 HOL. The 0-6 HOL is the shortest, most vulnerable period for IVH, thus, an early IVH is an IVH occurs in it. Such early IVH had prognostic, etiological/preventive and medicolegal implications. Accordingly, preterm neonates at risk of IVH should have their first routine screening head ultrasound at about 6 HOL. Future research exploring the antecedents of IVH should guaranty the temporality between these antecedents and IVH. Additional research will be required to determine whether the long term neurological outcomes of early and late IVH are the same.

A risk prediction model for severe intraventricular hemorrhage in very low birth weight infants and the effect of prophylactic indomethacin

OBJECTIVE

Develop a risk prediction model for severe intraventricular hemorrhage (IVH) in very low birth weight infants (VLBWI).

STUDY DESIGN

Prospectively collected data of infants with birth weight 500 to 1249 g born between 2001 and 2010 in centers from the Neocosur Network were used. Forward stepwise logistic regression model was employed. The model was tested in the 2011 cohort and then applied to the population of VLBWI that received prophylactic indomethacin to analyze its effect in the risk of severe IVH.

RESULT

Data from 6538 VLBWI were analyzed. The area under ROC curve for the model was 0.79 and 0.76 when tested in the 2011 cohort. The prophylactic indomethacin group had lower incidence of severe IVH, especially in the highest-risk groups.

CONCLUSION

A model for early severe IVH prediction was developed and tested in our population. Prophylactic indomethacin was associated with a lower risk-adjusted incidence of severe IVH.

Risk-adjusted intraventricular hemorrhage rates in very premature infants: towards quality assurance between neonatal units

BACKGROUND

The incidence of intraventricular hemorrhage (IVH) in very low birth weight infants can be used as an index of the quality of care in neonatal intensive care units as long as it is adjusted to reflect the infants' risk profiles on admission to the unit, which may vary systematically from one institution to another. Adjustment for gestational, birth-related, and neonatological risk factors enables a fair comparison of IVH rates across neonatal intensive care units.

METHODS

Data on 1782 neonates born at less than 32 weeks of gestation or weighing less than 1500 g at birth were retrieved from the 26 744 anonymous data sets collected in the Peri- and Neonatal Survey of the German state of Saxony in the years 2001-2005. An analysis of 30 putative risk factors with stepwise logistic regression analysis enabled the construction of a specific risk predictor for severe (grade 3-4) IVH. Risk-adjusted institutional incidence rates were then calculated.

RESULTS

Five independent risk factors (low gestational age, low Apgar scores at 1 min, early infection, absence of pathological Doppler findings during pregnancy, and the use of tocolytic agents) were found to be relevant to the prediction of IVH. A risk predictor incorporating them was found to have a correct prediction rate (ROC(AUC) value) of 87.7%. The crude incidence of severe IVH in different institutions ranged from 1.92% to 15.02% (mean, 8.55%); after adjustment, the range was 5.14% to 11.58%. When the institutions studied were ranked in order of their incidence of IVH before and after adjustment for risk factors, individual institutions rose or fell by as many as 4 places in the ranking because of the adjustment.

CONCLUSION

These findings reveal the importance of adjusting the incidence of IVH in very low birth weight infants by the patients' risk profiles to enable valid comparisons between institutions for the purpose of quality surveillance.

Optimum mode of delivery in gestations complicated by preterm premature rupture of the membranes

OBJECTIVES

To provide evidence about the preferable mode of delivery, vaginal (VD) or caesarean section (CS), in PPROM.

METHODS

A retrospective study of 190 cases. Survival analysis was used to identify statistically significant differences in mortality rates.

RESULTS

A total of 126 pregnancies were included in our study. Mean gestational age of rupture was 28(+0) weeks (min = 15, max = 36(+4), sd = 5.796). Mean birth age was 30(+0) weeks (min = 15, max = 37(+2), sd = 5.353). CS was performed in 55 cases (43.7%), VD in 71 cases (56.3%). Data analysis showed that, regardless of presentation, there was a statistically significant benefit on survival in favor of the CS in births below 30 gestational weeks (n = 39, nCS = 18, nND = 21, χ(2) = 7.946, p = 0.005). Hazard ratio estimation set the critical gestational age at 28 weeks. For vaginal deliveries, breech presentation was associated with inferior survival outcome compared to vertex (nTotal = 71; nVertex = 63, nBreech = 8, χ(2) = 13.012, p < 0.001.Also in breech presentation, VD survival outcome was inferior to CS (nTotal = 9; nVD = 6, nCS = 3, χ(2) = 5.145, p < 0.05).

CONCLUSIONS

According to our results, in cases of PPROM, CS was beneficial below 28 weeks and in breech presentation below 30 weeks.

Infantile posthemorrhagic hydrocephalus

INTRODUCTION

Intraventricular/germinal matrix hemorrhage affects 7-30% of premature neonates, 25-80% of whom (depending on the grade of the hemorrhage) will develop hydrocephalus requiring shunting. Predisposing factors are low birth weight and gestational age.

MATERIAL

There is increasing evidence for the role of TGF-β1 in the pathogenesis of hydrocephalus, but attempts to develop treatment modalities to clear the cerebrospinal fluid (CSF) from blood degradation products have not succeeded so far. Ultrasound is a valuable screening tool for high-risk infants and magnetic resonance imaging is increasingly utilized to differentiate progressive hydrocephalus from ex vacuo ventriculomegaly, evaluate periventricular parenchymal damage, decide on the surgical treatment of hydrocephalus, and follow up these patients in the long term. Treatment of increasing ventriculomegaly and intracranial hypertension in the presence of hemorrhagic CSF can involve a variety of strategies, all with relative drawbacks, aiming to drain the CSF while gaining time for it to clear and the neonate to reach term and become a suitable candidate for shunting. Eventually, patients with progressive ventriculomegaly causing intracranial hypertension, who have reached term and their CSF has cleared from blood products, will need shunting.

CONCLUSION

Cognitive long-term outcome is influenced more by the effect of the initial hemorrhage and other perinatal events and less by hydrocephalus, provided that this has been addressed timely in the early postnatal period. Shunting can have many long-term side effects due to mechanical complications and overdrainage. In particular, patients with posthemorrhagic hydrocephalus are more susceptible to multiloculated hydrocephalus and encysted fourth ventricle, both of which are challenging to treat.

Review of the recent literature on the mode of delivery for singleton vertex preterm babies

Choosing the safest method of delivery and preventing preterm labour are obstetric challenges in reducing the number of preterm births and improving outcomes for mother and baby. Optimal route of delivery for preterm vertex neonates has been a controversial topic in the obstetric and neonatal community for decades and continues to be debated. We reviewed 22 studies, most of which have been published over the last five years with an aim to find answers to the clinical questions relevant to deciding the mode of delivery. Findings suggested that the neonatal outcome does not depend on the mode of delivery. Though Caesarean section rates are increasing for preterm births, it does not prevent neurodisability and cannot be recommended unless there are other obstetric indications to justify it. Therefore, clinical judgement of the obstetrician depending on the individual case still remains important in deciding the mode of delivery.

Method of delivery and intraventricular haemorrhage in extremely preterm infants

OBJECTIVES

It has been reported that caesarean delivery (CD) protects against intraventricular haemorrhage (IVH) in the extremely preterm infant, but it is not known whether this effect involve the more severe grades of IVH. Thus, our aim was to confirm the correlation between the occurrence of IVH and the mode of delivery, and to evaluate this correlation for each grade of IVH.

METHODS

All infants with gestational age (GA) ≤ 28 weeks admitted to the neonatal intensive care unit of a tertiary hospital were studied for each grade IVH and major complications rate.

RESULT

We found that vaginally born infants had a higher rate of each grade of IVH, but the increase was statistically significant only for grade 3 IVH (18% vs. 2%, p < 0.0001) and all grades IVH (45% vs. 20%, p < 0.0001). Multivariate analysis demonstrated that CD (RR: 0.42, 95% CI 0.28-0.63), birth weight ≥ 800 g (RR: 0.48, 95% CI 0.32-0.73), 27-28 weeks of GA (RR: 0.38, 95% CI 0.25-0.60) and antenatal steroids (0.66, 95% CI 0.22-0.46) decrease independently the risk of developing IVH.

CONCLUSIONS

Our study demonstrates that CD decreases the risk of developing IVH in extremely preterm infants including the most severe grades of IVH.

Long-term neurologic outcome of infants born by cesarean section

Prevention of neurologic injury to the fetus through skilled and attentive care during the peripartum period is designed to identify signs of fetal distress so that appropriate obstetric interventions can occur. The impact of mode of delivery on neurologic outcome varies depending on the clinical indication for cesarean delivery and the associated maternal and fetal conditions. This review summarizes current knowledge of the impact of mode of delivery on long-term neurologic outcome.

Mechanisms of injury to the newborn brain

Preterm and ill term infants are at risk for brain injury and subsequent neurodevelopmental delay as a result of many perinatal factors. Outlined in this article are the basic science mechanisms by which hypoxia, hypocapnia, and hypercapnia may result in neuronal injury in the newborn brain.

The impact of vaginal delivery in premature infants weighing less than 1,251 grams

OBJECTIVE

To evaluate whether mode of delivery is a predictor of poor short-term outcome at different birth weight categories in very low birth weight infants.

METHODS

This study examined a cohort of infants weighing less than 1,251 g born at 2 perinatal centers from January 1, 2000, to December 31, 2003. Outborn infants or those with major anomalies were excluded from the study. Outcome variables included death, severe intraventricular hemorrhage, periventricular leukomalacia (PVL), and combined poor short-term outcomes (death, severe intraventricular hemorrhage, and PVL).

RESULTS

Of the 397 infants who met enrollment criteria, 44% were born vaginally and 56% by cesarean delivery. The proportion of multiparous, breech presentation and prolonged rupture of membranes was significantly different between groups. For infants weighing less than 751 g, the risks of severe intraventricular hemorrhage (41% versus 22%; odds ratio [OR] 2.79, 95% confidence interval [CI] 1.08-7.72) and combined poor short-term outcome (67% versus 41%; OR 2.95, 95% CI 1.25-6.95) were significantly higher if delivered vaginally. Among survivors weighing less than 751 g, the risk of severe intraventricular hemorrhage was higher among those delivered vaginally (24% versus 9%; OR 8.18, 95% CI 1.58-42.20). In infants less 1,251 g who survived, vaginal delivery had a strong association with PVL (5% versus 1%; OR 11.53, 95% CI 1.66-125).

CONCLUSION

In infants less than 1,251 g who survived to discharge, vaginal delivery is associated with higher risk for PVL. Furthermore, in infants less than 751 g, vaginal delivery is a predictor for severe intraventricular hemorrhage and combined poor short-term outcome. The negative impact of vaginal delivery mode decreases as birth weight category increases.

The blood-brain barrier: an overview: structure, regulation, and clinical implications

The blood-brain barrier (BBB) is a diffusion barrier, which impedes influx of most compounds from blood to brain. Three cellular elements of the brain microvasculature compose the BBB-endothelial cells, astrocyte end-feet, and pericytes (PCs). Tight junctions (TJs), present between the cerebral endothelial cells, form a diffusion barrier, which selectively excludes most blood-borne substances from entering the brain. Astrocytic end-feet tightly ensheath the vessel wall and appear to be critical for the induction and maintenance of the TJ barrier, but astrocytes are not believed to have a barrier function in the mammalian brain. Dysfunction of the BBB, for example, impairment of the TJ seal, complicates a number of neurologic diseases including stroke and neuroinflammatory disorders. We review here the recent developments in our understanding of the BBB and the role of the BBB dysfunction in CNS disease. We have focused on intraventricular hemorrhage (IVH) in premature infants, which may involve dysfunction of the TJ seal as well as immaturity of the BBB in the germinal matrix (GM). A paucity of TJs or PCs, coupled with incomplete coverage of blood vessels by astrocyte end-feet, may account for the fragility of blood vessels in the GM of premature infants. Finally, this review describes the pathogenesis of increased BBB permeability in hypoxia-ischemia and inflammatory mechanisms involving the BBB in septic encephalopathy, HIV-induced dementia, multiple sclerosis, and Alzheimer disease.

Delivery modes and neonatal EEG: spatial pattern analysis

BACKGROUND

Animal studies indicate that postnatal adaptation and development of neonates could be different due to the birth method and that these effects may last throughout adulthood.

STUDY DESIGN

We applied a spatio-temporal analysis to EEG recordings of a group of neonates to investigate the influence of a cesarean section on maturation and extrauterine adaptation of the brain. EEG were recorded at 2 h and at 24 h after delivery.

SUBJECTS

A spectral analysis technique, the so-called Karhunen-Loeve (KL) method, was applied to EEG of 10 neonates from vaginal delivery and 17 from C-section to obtain the spatio-temporal eigenpatterns.

RESULTS

Spatio-temporal analysis showed noticeable pattern differences between the two groups. Compared to the C-section, the vaginal delivered neonate's EEG recordings showed a significant increase of amplitude at Fp1 in the pattern 24 h after the delivery, but not 2 h after delivery. Dynamics in this spectral analyses were not significantly different between both groups 2 h after delivery, but the regional differences increased during the next day between both groups.

CONCLUSIONS

This could come from the early insufficient complexity in C-section neonates. Global EEG complexity in C-section neonates fell short of that of vaginal delivered neonates 2 h after delivery. Many aspects of pattern change in C-section neonates followed the nature of vaginal delivered neonates. These could be considered as parts of a retarded transition of C-section neonates in the early adaptation, but some of the differences in global EEG pattern could not be explained in this way. Pattern analysis suggests that the neuronal activities of the neonatal brain are changing regionally concurrent with bi-hemispheric global dynamics. Moreover, the delivery modes could have an influence on the early postneonatal adaptation of the physiological activity in brain.

Does labor influence neonatal and neurodevelopmental outcomes of extremely-low-birth-weight infants who are born by cesarean delivery?

OBJECTIVE

The purpose of this study was to examine the influence of labor on extremely-low-birth-weight infants who were born by cesarean delivery with reference to neonatal and neurodevelopmental outcomes. We hypothesized that infants who are born by cesarean delivery without labor will have better outcomes than those infants who are born by cesarean delivery with labor.

STUDY DESIGN

This was a retrospective cohort study of extremely-low-birth-weight infants (birth weight, 401-1000 g) who were born by cesarean delivery and cared for in the National Institute for Child Health and Human Development Neonatal Network, during calendar years 1995 to 1997. A total of 1606 extremely-low-birth-weight infants were born by cesarean delivery and survived to discharge. Of these, 1273 infants (80.8%) were examined in the network follow-up clinics at 18 to 22 months of corrected age and had a complete data set (667 infants were born without labor, 606 infants were born with labor). Outcome variables that were examined include intraventricular hemorrhage grade 3 to 4, periventricular leukomalacia, and neurodevelopmental impairment.

RESULTS

Mothers in the cesarean delivery without labor group were older (P<.001), more likely to be married (P<.05), less likely to be supported by Medicaid (P<.01), more likely to have preeclampsia/hypertension (P<.001), more likely to receive prenatal steroids (P<.005), and less likely to have received antibiotics (P<.001). Infants who were born by cesarean delivery without labor had higher gestational age (P<.001), lower birth weight (P<.01), and were less likely to be outborn (P<.001). By univariate analysis, infants who were born by cesarean delivery with labor had a higher incidence of grade 3 to 4 intraventricular hemorrhage (23.3% vs 12.1%, P<.001), periventricular leukomalacia (8.5% vs 4.7%, P<.02), and neurodevelopmental impairment (41.7% vs 34.6%, P<.02). Logistic regression analysis that controlled for all maternal and neonatal demographic and clinical variables that were statistically associated with labor or no labor revealed that the significant differences in grade 3 to 4 intraventricular hemorrhage, periventricular leukomalacia, and neurodevelopmental impairment were no longer evident.

CONCLUSION

In extremely-low-birth-weight infants who were born by cesarean delivery and after control for other risk factors, labor does not appear to play a significant role in adverse neonatal outcomes and neurodevelopmental impairment at 18 to 22 months of corrected age.

Perinatal risk factors for major intraventricular haemorrhage in the Australian and New Zealand Neonatal Network, 1995-97

BACKGROUND

In 1995, large differences were identified in rates of grade 3-4 intraventricular/periventricular haemorrhage (major IVH) among neonatal intensive care units (NICUs) in the Australian and New Zealand Neonatal Network.

AIMS

To develop a predictive model for major IVH in order to allow risk adjustment for the variation in rates of major IVH among NICUs.

METHODS

Rates of IVH were determined in 5712 infants of 24-30 weeks gestation born from 1995 to 1997. Significant antenatal and perinatal variables for major IVH in 1995 and 1996 were identified by univariate and multivariate analysis. A predictive model was developed and then validated on 1997 data.

RESULTS

Rates of all grades of IVH fell from 1995 to 1997 (30.4 to 24.3%) but wide interunit variation remained. Seven antenatal and perinatal characteristics had significant association with major IVH: fetal distress, intrauterine growth restriction (protective), antenatal corticosteroids (protective), gestational age, 1 minute Apgar <4, male gender, and transfer after birth. A predictive model based on the last five of these variables was developed using data from 1995 and 1996 which gave an area under the receiver operator characteristic (ROC) curve of 0.76. This model was then validated on the 1997 dataset where an identical ROC curve resulted.

CONCLUSIONS

Antenatal and perinatal factors are important in the pathogenesis of major IVH. The predictive model developed from these factors can be used to adjust for confounders in interunit outcome comparison.

Temporal expression pattern of cerebrovascular endothelial cell alkaline phosphatase during human gestation

In premature human neonates, immaturity of cerebral vessels can contribute to clinical problems such as germinal matrix hemorrhage and white matter damage. Afferent cerebral vessels in the brain of term babies express alkaline phosphatase (AP), an ectoenzyme located on the surface of endothelial cells. Using AP enzyme histochemistry we have examined the cerebrovasculature of premature live-born human neonates to determine when cerebral afferent vessels begin to express AP. Brains were collected at autopsy and processed for histological examination. AP-stained vessel density in the periventricular white matter was quantified using digital imaging and automated morphometry. Babies born prior to 28 wk gestation display few AP-positive vessels in the periventricular white matter, whereas, babies born after 28 wk gestation exhibit an AP-positive vascular pattern that resembles the adult pattern. In contrast, immunostaining for collagen revealed an extensive vascular network in both early and late gestation infants. Our measurements indicate that neonates born prior to 28 wk gestation are characterized by immature cerebral white matter afferent vessels and raise the possibility that the immaturity compromises vascular function.

Association of thrombocytopenia and delivery method with intraventricular hemorrhage among very-low-birth-weight infants

OBJECTIVES

To investigate the significance of neonatal thrombocytopenia and delivery method on the incidence of intraventricular hemorrhage in infants weighing <1500 g.

STUDY DESIGN

A total of 1283 infants weighing <1500 g who were admitted to six neonatal intensive care units over 21 months were analyzed prospectively. Illness severity was measured by the Score for Neonatal Acute Physiology (SNAP).

RESULTS

Of the infants analyzed, 145 (11.3%) had thrombocytopenia (platelet count <100 x 10(9)/L). The incidence of intraventricular hemorrhage was greater among infants with thrombocytopenia than among those without (44.8% vs 23.9%, P <.0001). Non-thrombocytopenic infants who were delivered vaginally had a higher incidence of intraventricular hemorrhage than those delivered via cesarean section (35.8% vs 15.9%, P <.0001). Thrombocytopenic infants who were delivered vaginally had the highest incidence of intraventricular hemorrhage (63.4% vs 37.5% for cesarean section, P =.005). Vaginal delivery and platelets < 50 x 10(9)/L on day 1 were independent risk factors for intraventricular hemorrhage (OR 2.7, 95% CI 2.0-3.8 and OR 11.2, 95% CI 3.0-42.5, respectively).

CONCLUSIONS

This multicenter study confirms that thrombocytopenia and intraventricular hemorrhage are not uncommon in neonates who weigh <1500 g, and that the incidence of intraventricular hemorrhage is higher in those thrombocytopenic infants delivered vaginally.

Perinatal glucocorticoid therapy and neurodevelopmental outcome: an epidemiologic perspective

A relatively brief course of antenatal glucocorticoids (ACS), given to reduce the severity of respiratory distress syndrome in preterm infants, improves survival and appears to protect against brain damage. In clinical trials as well as observational studies, ACS have been associated with a decreased risk of intraventricular haemorrhage and cerebral palsy. In observational studies a decreased risk of white-matter damage, identified with cranial ultrasound, has been observed. There is some evidence, from observational studies, that repeated courses of ACS (typically given at weekly intervals) can reduce the rate of fetal head growth, and experiments in animals provide further support for this possibility. In contrast to the effects of a brief course of ACS, postnatal glucocorticoids (PCS), given to preterm infants to reduce the severity of chronic lung disease have been associated with an increased risk of neurologic impairment. Available evidence suggests that PCS does not improve survival. Further study is needed of the neurodevelopmental consequences of both multiple courses of ACS, as well as PCS.

Effect of maternal tocolysis on the incidence of severe periventricular/intraventricular haemorrhage in very low birthweight infants

AIM

To examine the relation between grade III-IV periventricular/intraventricular haemorrhage (PVH/IVH) and antenatal exposure to tocolytic treatment in very low birthweight (VLBW) premature infants.

STUDY DESIGN

The study population consisted of 2794 infants from the Israel National VLBW Infant Database, of gestational age 24-32 weeks, who had a cranial ultrasound examination during the first 28 days of life. Infants of mothers with pregnancy induced hypertension or those exposed to more than one tocolytic drug were excluded. Of the 2794 infants, 2013 (72%) had not been exposed to tocolysis and 781 (28%) had been exposed to a single tocolytic agent. To evaluate the effect of tocolysis and confounding variables on grade III-IV PVH/IVH, the chi(2) test, univariate analysis, and a logistic regression model were used.

RESULTS

Of the 781 infants (28%) exposed to tocolysis, 341 (12.2%) were exposed to magnesium sulphate, 263 (9.4%) to ritodrine, and 177 (6.3%) to indomethacin. The overall incidence of grade III-IV PVH/IVH was 13.4%. In the multivariate logistic regression analysis, the following factors were related significantly and independently to grade III-IV PVH/IVH: no prenatal steroid treatment, low gestational age, one minute Apgar score 0-3, respiratory distress syndrome, patent ductus arteriosus, mechanical ventilation, and pneumothorax. Infants exposed to ritodrine tocolysis (but not to the other tocolytic drugs) were at significantly lower risk of grade III-IV PVH/IVH after adjustment for other variables (odds ratio = 0.3; 95% confidence interval 0.2 to 0.6).

CONCLUSION

This study suggests that antenatal exposure of VLBW infants to ritodrine tocolysis, in contrast with tocolysis induced by magnesium sulphate or indomethacin, was associated with a lower incidence of grade III-IV PVH/IVH.

The great tocolytic debate: some pitfalls in the study of safety

The controversy surrounding the use of tocolytic agents has been raging for decades. Tocolytic drugs play a pivotal role in the prevention of preterm birth, which is the major cause of neonatal morbidity and mortality. Studies on the efficacy and safety of these drugs are of the utmost importance to many disciplines within the medical community. Unfortunately, many clinical decisions regarding tocolytic agents are based on incorrect information resulting from flawed studies. In this article we discuss the major design flaws common to many studies of tocolytic safety and in so doing explain some of the conflicting evidence regarding safety. Each of the two major types of study designs, preterm birth retrospective studies and prospective randomized trials, is associated with a serious flaw. Retrospective preterm birth studies give misleading and inconclusive results to the question of safety because of the use of incomplete cohorts. The inadequately sized prospective studies in the current literature lack the power to detect important clinical differences.

Low superior vena cava flow and intraventricular haemorrhage in preterm infants

OBJECTIVES

To document the incidence, timing, degree, and associations of systemic hypoperfusion in the preterm infant and to explore the temporal relation between low systemic blood flow and the development of intraventricular haemorrhage (IVH).

STUDY DESIGN

126 babies born before 30 weeks' gestation (mean 27 weeks, mean body weight 991 g) were studied with Doppler echocardiography and cerebral ultrasound at 5, 12, 24, and 48 hours of age. Superior vena cava (SVC) flow was assessed by Doppler echocardiography as the primary measure of systemic blood flow returning from the upper body and brain. Other measures included colour Doppler diameters of ductal and atrial shunts, as well as Doppler assessment of shunt direction and velocity, and right and left ventricular outputs. Upper body vascular resistance was calculated from mean blood pressure and SVC flow.

RESULTS

SVC flow below the range recorded in well preterm babies was common in the first 24 hours (48 (38%) babies), becoming significantly less common by 48 hours (6 (5%) babies). These low flows were significantly associated with lower gestation, higher upper body vascular resistance, larger diameter ductal shunts, and higher mean airway pressure. Babies whose mothers had received antihypertensives had significantly higher SVC flow during the first 24 hours. Early IVH was already present in 9 babies at 5 hours of age. Normal SVC flows were seen in these babies except in 3 with IVH, which later extended, who all had SVC flow below the normal range at 5 and/or 12 hours. Eight of these 9 babies were delivered vaginally. Late IVH developed in 18 babies. 13 of 14 babies with grade 2 to 4 IVH had SVC flow below the normal range before development of an IVH. Two of 4 babies with grade 1 IVH also had SVC flow below the normal range before developing IVH, and the other 2 had SVC flow in the low normal range. In all, IVH was first seen after the SVC flow had improved, and the grade of IVH related significantly to the severity and duration of low SVC flow. The 9 babies who had SVC flow below the normal range and did not develop IVH or periventricular leucomalacia were considerably more mature (median gestation 28 v 25 weeks).

CONCLUSIONS

Low SVC flow may result from an immature myocardium struggling to adapt to increased extrauterine vascular resistances. Critically low flow occurs when this is compounded by high mean airway pressure and large ductal shunts out of the systemic circulation. Late IVH is strongly associated with these low flow states and occurs as perfusion improves.

Mechanisms of perinatal brain injury

This article is focused on the mechanisms underlying primarily ischaemic/reperfusion brain injury in both the term and premature infant. Although the mechanisms involved include similar initiating events, principally ischaemia-reperfusion, and similar final common pathways to cell death, particularly free radical-mediated events, there are certain unique maturational factors influencing the type and pattern of cellular injury. We will therefore initially describe the physiological and cellular/molecular mechanisms of brain injury in the term infant, followed by the mechanisms in the premature infant.

Intraventricular hemorrhage in very low birth weight infants: associated risk factors and outcome in the neonatal period

Intraventricular hemorrhage (IVH) is a severe complication in very low birth weight (VLBW) newborns (NB). With the purpose of studying the incidence of IVH, the associated risk factors, and the outcomes for these neonates, we studied all the VLBW infants born in our neonatal unit. Birth weight, gestational age, presence of perinatal asphyxia, mechanical ventilation, length of hospitalization, apnea crisis, hydrocephalus, and periventricular leukomalacia were analyzed. The diagnosis of IVH was based on ultrasound scan studies (Papile's classification) performed until the tenth day of life and repeated weekly in the presence of abnormalities. Sixty-seven/101 neonates were studied. The mortality rate was 30.6% (31/101) and the incidence of IVH was 29.8% (20/67) : 70% grade I, 20% grade III and 10% grade IV. The incidence of IVH in NB <1,000 g was 53.8% (p = 0. 035) and for gestational age <30 weeks was 47.3% (p = 0.04), both considered risk factors for IVH. The length of hospitalization (p = 0.00015) and mechanical ventilation (p = 0.038) were longer in IHV NB. The IVH NB had a relative risk of 2.3 of developing apnea (p = 0. 02), 3.7 of hydrocephalus (p = 0.0007), and 7.7 of periventricular leukomalacia (p < 0.00001). The authors emphasize the importance of knowing the risk factors related to IVH so as to introduce prevention schemes to reduce IVH and to improve outcomes of affected newborns.

Posthemorrhagic hydrocephalus and brain injury in the preterm infant: dilemmas in diagnosis and management

Advances in neonatal critical care have reduced the incidence of intraventricular hemorrhage (IVH) in the newborn. Paradoxically, however, the prevalence of the complications of IVH including posthemorrhagic hydrocephalus (PHHC) has increased. By virtue of its association with long-term neurodevelopmental disability, posthemorrhagic hydrocephalus is an ominous diagnosis in the premature infant. Animal models have demonstrated that ventricular distention may cause direct cerebral parenchymal injury. Evidence for secondary parenchymal injury in the premature infant with PHHC is by necessity indirect. The precise impact of secondary parenchymal injury on the overall neurological outcome of premature infants with PHHC remains unclear in large part because of the vulnerability of the immature brain to other forms of injury (e.g., periventricular leukomalacia) that may be difficult to distinguish from injury due to distention. Furthermore, parenchymal injury due to PVL may cause ventricular enlargement that does not benefit from CSF diversion. Because these primary and secondary mechanisms of injury may operate concurrently, the precise or dominant cause of ventricular enlargement is often difficult to establish with certainty in the neonatal period. These diagnostic dilemmas have in turn impeded the development and evaluation of therapies specifically aimed at reversing ventricular distention and preventing secondary parenchymal injury. This article focuses on the current dilemmas in diagnosis and management of this potentially reversible form of injury as well as on potential future strategies for its prevention.

Intraventricular hemorrhage: emphasis on prevention

Germinal matrix/intraventricular hemorrhage is a common type of cerebral injury in premature newborns. Based on the improved understanding of underlying pathogenetic mechanisms, numerous interventional strategies for prevention have been proposed. This article summarizes and evaluates the efficacy and safety of major interventions that are currently under consideration for the prevention of germinal matrix/intraventricular hemorrhage.

Trends in incidence and severity of intraventricular hemorrhage

The incidence of germinal matrix-intraventricular hemorrhages declined from 50% in 1977 to 24% in 1985. Over the last decade intraventricular hemorrhage rates ranging from 8% to 56% were reported, leaving uncertainty as to the direction of recent intraventricular hemorrhage trends. Records of all 1950 neonates weighing 2250 g or less at birth (867 weighing 1500 g or less and 1083 weighing 1501-2250 g) at a university neonatal intensive care unit between 1986 and 1995 were studied. Intraventricular hemorrhage rate declined by 53%, from 11.5% in 1986 to 5.5% in 1995 (P < .01), and was consistent across all birthweight groups: 750 g or less from 36% to 24%, 751-1000 g from 38% to 22%, 1001-1250 g from 19% to 13%, 1251-1500 g from 12% to 2% and 1551-2250 g from 3% to 0.2% (P < .05). Proportionately, severe intraventricular hemorrhage (grades 3 +/- intraparenchymal hemorrhage) declined from 70% of all intraventricular hemorrhages in 1986 to 23% in 1995 (P < .005). Overall mortality declined by 65% between 1986 and 1995 (P < .001), whereas mortality associated with intraventricular hemorrhage declined by 30% (P = .34). Despite dramatic declines in intraventricular hemorrhage rates, 21% of infants weighing less than 1000 g and 12% of those weighing less than 1500 g at birth were affected in 1995.

The correlation between placental pathology and intraventricular hemorrhage in the preterm infant. The Developmental Epidemiology Network Investigators

The aim of this study is to better understand the relationship between placental pathology and risk of intraventricular hemorrhage (IVH). We address two specific hypotheses. 1) Morphologic correlates of pregnancy-induced hypertension (PIH) are associated with a decreased risk of IVH. 2) Morphologic correlates of amniotic sac inflammation (ASI) are associated with an increased risk of IVH. Maternal, neonatal, and placental data were analyzed by univariate and multivariate methods in this prospective cohort study of 1095 very low birth weight infants. A cluster analysis model was used to categorize the placental pathologic features into clusters, the two main ones being PIH and ASI. Deliveries were subdivided by the interval between membrane rupture and delivery as an index of preexisting infection (<1 h) and ascending infection (> or =1 h). Univariate analysis supports both hypotheses. However, in multivariate models that adjusted for such potential confounders as gestational age, labor, and route of delivery, the only associations that persisted were the increased risk of IVH associated with the presence of chorionic or umbilical vasculitis in infants born within 1 h of membrane rupture. Placental correlates of PIH do not provide additional information about IVH risk independent of the presence of other components of the PIH and ASI clusters, and confounders such as gestational age, labor, and route of delivery. Placental correlates of ASI, specifically the fetal responses of chorionic and umbilical vasculitis to preexisting infection, are associated with an increased risk of IVH independent of confounders. Cytokines may provide the link between placental inflammation and fetal/neonatal brain hemorrhage.

Peri/intraventricular haemorrhage: a cranial ultrasound study on 5286 neonates

OBJECTIVE

We launched a prospective cranial ultrasound study at the Department of Obstetrics and Gynaecology of the University of Giessen. In this study we examined the incidence and severity of brain damage in neonates and related them to various obstetrical risk factors.

STUDY DESIGN

More than 90% of all neonates born between 1984 and 1988 were included in the study (n = 5286) and were screened by ultrasound for cerebral abnormalities on 5-8 days post-partum. The relation between the incidence of peri/intraventricular haemorrhages (PIVH) and obstetrical risk factors were analyzed by contingency tables.

RESULTS

The most frequent abnormality was PIVH (3.6%) of various degrees (grade I-III). Periventricular leucomalacia, porencephalia, subarachnoidal haemorrhages, and hydrocephali were rare (< or = 0.2%). The incidence of PIVH increased progressively with decreasing gestational age, e.g. from 1.6% at 38-43 weeks up to 50.0% at 24-30 weeks of gestation. A large percentage of babies with PIVH were clinically normal. In immature neonates there was a close inverse relationship between Apgar score at 1, 5 and 10 min and both incidence and severity of PIVH. This was in contrast to findings in mature neonates where a marked increase in the incidence of PIVH was found only with Apgar scores as low as 0-4 points. The relation between the incidence of PIVH and both cardiotocography and arterial cord blood pH was poor, independent of the gestational age. The incidence of PIVH was increased in growth retarded fetuses (pH < or = 7.29), premature rupture of membranes, fever sub partu and gestosis. It is interesting to note that in mature fetuses there was no difference in the incidence of PIVH between vaginally delivered (0.8%) and sectioned breech presentations (2.1%). In preterms at 35-37 weeks with prolonged labour and secondary cesarean section, the incidence of PIVH was very high (11.2%).

CONCLUSION

From the present study we conclude that the incidence of PIVH especially in immature neonates is highly associated with low Apgar scores at birth. Since the Apgar score reflects the clinical condition and the degree of circulatory centralisation of neonates that is influenced by various ante- and intranatal risk factors, a protective obstetrical management is necessary to reduce the incidence of PIVH in neonates.

Outcome for preterm infants with germinal matrix hemorrhage and progressive hydrocephalus

OBJECTIVE

An analysis of 76 preterm infants with Grade III or IV intracranial hemorrhage and surgically treated progressive hydrocephalus was undertaken to determine mortality, intellectual impairment, and motor deficit.

METHODS

The variables examined were degree of prematurity, birth weight, sex, Apgar scores, extent of intracranial hemorrhage, seizures, age at time of initial placement of a ventricular catheter reservoir to control hydrocephalus, need to convert the reservoir to a ventriculoperitoneal shunt, timing of the conversion of the reservoir to a ventriculoperitoneal shunt, and number of shunt revisions. Outcome was assessed for statistical significance using hierarchical linear regression and logistic regression analyses.

RESULTS

Linear regression analysis determined that mortality was best predicted, in order of importance, by extent of intracranial hemorrhage, number of shunt revisions, and birth weight (P < 0.0001, R = 0.79). Grade of hemorrhage, weight at birth, and presence of seizure activity were the most important determinants of motor outcome (P < 0.001, R = -0.78).

CONCLUSIONS

Logistic regression analysis of the 41 long-term survivors determined that grade of hemorrhage was the most important variable in determining cognitive outcome (P < 0.0001), motor function (P < 0.0001), and presence of seizure activity (P < 0.001). A logistic model of survival determined that grade of hemorrhage and multiple shunt revisions (more than five) were the most important determinants (P < 0.0001) of survival. In conclusion, the overwhelming factor in determining outcome in this patient group was the extent of intracranial hemorrhage.

An in vitro three-dimensional coculture model of cerebral microvascular angiogenesis and differentiation

The microvasculature of the developing brain is plastic and responds differently to the many insults associated with preterm birth. We developed three-dimensional in vitro culture models for the study of the responses of the developing cerebral microvasculature. Beagle brain microvascular endothelial cells (BBMEC) were isolated by differential centrifugation from newborn beagle pups on postnatal Day 1 and placed in three-dimensional culture dispersed in a collagen gel. Alternatively, BBMEC were placed in a three-dimensional coculture with neonatal rat forebrain astrocytes. Cultures were analyzed for extracellular matrix components at 1 and 6 d, and total RNA was extracted for Northern analyses. Urokinase plasminogen activator activity was assayed in both mono- and cocultures of the two cell types. Studies of three-dimensional BBMEC/astrocyte cocultures demonstrated progressive tube formation with only low levels of endothelial proliferation. By 6 d in three-dimensional coculture, the BBMEC formed capillarylike tubes with a wrapping of glial processes, and basement membrane protein synthesis was noted. Urokinase plasminogen zymography suggested intercellular signaling by the two cell types. These data suggest that the three-dimensional beagle brain germinal matrix microvascular endothelial cell/neonatal rat astrocyte coculture provides a good model for the investigation of microvascular responses in the developing brain.

Predictors of ventriculoperitoneal shunt among babies with intraventricular hemorrhage

We aimed to identify medical care practices that influence the need for ventriculoperitoneal shunt among infants who develop intraventricular hemorrhage. We reviewed the medical records of 82 babies with ultrasonographically documented intraventricular hemorrhage. We compared the 10 babies who required a ventriculoperitoneal shunt to the 72 controls who had intraventricular hemorrhage, but did not require a ventriculoperitoneal shunt or die, prior to discharge. We considered maternal, perinatal, and neonatal risk factors as potential predictive variables. Maternal preeclampsia, prenatal steroids, and cesarean delivery were associated with a reduced risk of shunt. Patients who did require a shunt were more likely than their nonshunted peers to be treated with dopamine, to receive greater volumes of total intravenous fluid, largely as albumin and red blood cells, and to have a higher incidence of acidosis, patent ductus arteriosus and systolic hypertension. Previously identified antecedents and correlates of intraventricular hemorrhage appear also to be the antecedents and correlates of progression to ventriculoperitoneal shunt among infants with intraventricular hemorrhage. These findings are consistent with the possibility that prenatal and postnatal care practices influence the risk for ventriculoperitoneal shunt among babies with intraventricular hemorrhage. This offers the promise that changes in obstetric and neonatal care will reduce the need for ventriculoperitoneal shunt in very low birthweight infants.

Pregnancy-induced hypertension and reduced intraventricular hemorrhage in preterm infants

Increasing evidence suggests that the incidence of periventricular intraventricular hemorrhage (PV-IVH) is lower in infants born to mothers with pregnancy-induced hypertension (PIH). The mechanism or mechanisms accounting for this reduction remain unclear but may be related to PIH itself, medications used to treat the mother (e.g., magnesium sulfate), or to obstetrical management. In this retrospective analysis, we determined the incidence of PV-IVH in singleton preterm infants weighing less than 1,500 gm born to mothers with PIH who were also administered magnesium sulfate. Between January 1988 and December 1994, 254 singleton infants born to mothers with PIH and 1,083 born to mothers without PIH were studied. PV-IVH developed in 360 (26.9%) of the 1,337 infants; 977 (74.1%) infants did not exhibit PV-IVH. The incidence of total as well as severe PV-IVH was lower in infants born to mothers with PIH than in those without PIH [i.e., 16% vs 30% (total) and 8.2% vs 14.5% (severe), P < .001] with an odds ratio (OR) estimate of 0.43 [95% confidence interval (CI) 0.30, 0.61]. Infants born to mothers with PIH weighed more, (1,152 +/- 250 gm vs 1,058 +/- 283 gm, P < .001) and were more mature (30.1 +/- 2.9 vs 27.7 +/- 31 weeks, P < .001) than infants born to mothers without PIH. These infants were also less likely to be exposed to labor (57% vs 93%), to be delivered by cesarean section (81% vs 35%), and to require intubation (49% vs 58%), but more likely to exhibit respiratory distress syndrome (RDS) (47% vs 38%, P < .01). By logistic regression analysis, after seven variables (i.e., PIH, gestational age, and birthweight, both modeled as cubic polynomials; labor; intubation; RDS; and race) were included in the analytic model, PIH remained a significant predictor of IVH: P = .006, OR = 0.54 (95% CI 0.349, 0.847). These data indicate a significantly lower incidence of PV-IVH of approximately 50% in infants born to mothers with PIH as compared with the incidence in infants born to mothers without PIH, despite their higher incidence of RDS. The reduction in PV-IVH may be directly related to the PIH; however, the independent role of antenatal magnesium sulfate administration requires further study.