Cellular and humoral coagulation profiles and occurrence of IVH in VLBW and ELWB infants

Estimation of gestational age-specific reference intervals for coagulation assays in a neonatal intensive care unit using real-world data

BACKGROUND

Interpretation of coagulation testing in neonates currently relies on reference intervals (RIs) defined from older patient cohorts. Direct RI studies are difficult, but indirect estimation may allow us to infer normative neonatal distributions from routinely collected clinical data.

OBJECTIVE

Assess the utility of indirect reference interval methods in estimating coagulation reference intervals in critically ill neonates.

METHODS

We analyzed first-in-life coagulation testing results from all patients admitted to a level IV neonatal intensive care unit between January 1, 2018, and January 1, 2024. Results obtained after transfusion of any blood product were excluded. Indirect RIs were estimated across gestational age groups using refineR and compared with currently reported intervals for patients less than 1 year of age.

RESULTS

Prothrombin times (PTs) and international normalized ratios (INRs) were available for 1128 neonates, while activated partial thromboplastin times (APTTs) were available for 790 neonates. The indirect RI was 10 to 25 seconds in preterm, 10 to 22 seconds in term, and 10 to 24 seconds in all neonates for PT; 0.7 to 2.1 in preterm, 0.8 to 1.8 in term, and 0.8 to 1.9 in all neonates for INR; and 25 to 68 seconds in preterm, 25 to 58 seconds in term, and 25 to 62 seconds in all neonates for APTT. Compared with our current intervals, the indirect RIs would flag 58% fewer PT, 43% fewer INR, and 17% fewer APTT results as abnormal.

CONCLUSION

Indirectly estimated RIs in neonates admitted to intensive care show substantial divergence from current, first-year-of-life RIs, leading to an abundance of abnormal flags. The associations between these flags and provider behavior, transfusion practice, or clinical outcomes are areas of future exploration.

Betamethasone treatment-to-delivery interval, retreatment, and severe intraventricular hemorrhage in infants <28 weeks' gestation

BACKGROUND

Antenatal corticosteroids decrease the incidence of severe intraventricular hemorrhage (grades 3, 4) in preterm infants. It is unclear whether their beneficial effects on intraventricular hemorrhage wane with time (as occurs in neonatal respiratory distress) and if repeat courses can restore this effect. Previous randomized controlled trials of betamethasone retreatment found no benefit on severe intraventricular hemorrhage rates. However, the trials may have included an insufficient number of infants at risk for intraventricular hemorrhage to be able to adequately address this question. Severe intraventricular hemorrhages occur almost exclusively in infants born at <28 weeks' gestation, whereas only 7% (0%-16%) of the retreatment trials' populations were <28 weeks' gestation.

OBJECTIVE

This study aimed to determine if the risk for severe intraventricular hemorrhage in infants delivered at <28 weeks' gestation increases when the betamethasone treatment-to-delivery interval increases beyond 9 days and to determine if betamethasone retreatment before delivery decreases the rate of hemorrhage.

STUDY DESIGN

This was an observational study that examined the incidence of intraventricular hemorrhage before (epoch 1) and after (epoch 2) a practice change that encouraged obstetricians to retreat pregnant women still at high risk for delivery before 28 weeks' gestation when >9 days elapsed from the first dose of betamethasone. Multivariable analyses with logistic regression using generalized estimating equation techniques were conducted to examine the rates of intraventricular hemorrhage among 410 infants <28 weeks' gestation who were either delivered between 1 to 9 days (n=290) after the first 2-dose betamethasone course or ≥10 days (and eligible for retreatment) after the first course (n=120).

RESULTS

After adjusting for potential confounding variables, infants who were delivered ≥10 days after a single betamethasone course had an increased risk for either severe intraventricular hemorrhage alone or the combined outcome severe intraventricular hemorrhage or death before 4 days (odds ratio, 2.8; 95% confidence interval, 1.2-6.6) when compared with infants who were delivered between 1 and 9 days after betamethasone. Among the 120 infants who were delivered ≥10 days after the first dose of betamethasone, 64 (53%) received a second or retreatment course of antenatal betamethasone. The severe intraventricular hemorrhage rate in infants whose mothers received a second or retreatment course of betamethasone was similar to the rate among infants who delivered within 1 to 9 days and significantly lower than among those who delivered ≥10 days without retreatment (odds ratio, 0.10; 95% confidence interval, 0.02-0.65). Following the change in guidelines, the rate of retreatment in infants who were delivered ≥10 days after the first betamethasone course (and before 28 weeks) increased from epoch 1 to epoch 2 (25% to 87%; P<.001) and the rate of severe intraventricular hemorrhage decreased from 22% to 0% (P<.001). In contrast, the rate of severe intraventricular hemorrhage among infants who were delivered 1 to 9 days after the initial betamethasone dose (who were not eligible for retreatment) did not change between epochs 1 and 2 (12% and 11%, respectively).

CONCLUSION

Although betamethasone's benefits on severe intraventricular hemorrhage appear to wane after the first dose, retreatment with a second course seems to restore its beneficial effects. Encouraging earlier retreatment of women at high risk for delivery before 28 weeks was associated with a lower rate of severe intraventricular hemorrhages among infants delivered at <28 weeks' gestation.

The Prevalence and Associated Risk Factors for Neonatal Thrombocytopenia Among Newborns Admitted to the Neonatal Intensive Care Unit

Background Thrombocytopenia is the most prevalent hematological condition in neonates that develops in the neonatal intensive care unit (NICU). This set of illnesses is caused by either decreased platelet production due to placental insufficiency, increased platelet breakdown (consumption), or a combination of the two causes. Based on platelet count, it is defined as mild, moderate, or severe thrombocytopenia, with early and late onset. Purpose The purpose of this study is to determine the prevalence of thrombocytopenia and the factors that contribute to it in newborns hospitalized in the neonatal critical care unit at the Maternity and Children Hospital in Al Ahsa, Saudi Arabia. Methods This descriptive retrospective cross-sectional study was carried out at the NICU of the Maternity and Children Hospital in Al Ahsa, Saudi Arabia, over the span of one year (August 2022 to August 2023) among hospitalized neonates with thrombocytopenia. Thrombocytopenia is defined as a platelet count of 150,000 or less. These patients were monitored until they recovered or died. Results The inclusion criteria were met by a total of 242 newborns with thrombocytopenia. Half of the neonates (57%) were full-term, with Apgar scores greater than 5 at the first (84%) and fifth (93%) minutes, respectively. The great majority of individuals (84%) experienced early-onset thrombocytopenia of mild severity (62%) and were asymptomatic (93%). The majority of the cases resolved spontaneously, with only 21% requiring platelet transfusion. There was a significant relationship discovered between gestational age and the severity of thrombocytopenia, with very preterm infants having moderate to severe thrombocytopenia, as well as birth weight (p=0.001). Furthermore, neonates with severe thrombocytopenia had a considerably higher mortality rate (p=0.001). Conclusion The mortality and morbidity of newborns with perinatal risk for neonatal thrombocytopenia can be reduced with timely detection of the cause and development of thrombocytopenia, as well as adequate and early care.

Assessment of Hemostatic Profile in Neonates with Intrauterine Growth Restriction: A Systematic Review of Literature

Intrauterine growth restriction (IUGR) affects nearly 10 to 15% of pregnancies and is responsible for many short- and long-term adverse consequences, including hemostatic derangement. Both thrombotic and hemorrhagic events are described in the perinatal period in these neonates. The aim of this study was to systematically review the literature on the laboratory studies used to evaluate the hemostatic system of the IUGR small for gestational age neonate. We reviewed the current literature via PubMed and Scopus until September 2022. Following our inclusion/exclusion criteria, we finally included 60 studies in our review. Thrombocytopenia, characterized as hyporegenerative and a kinetic upshot of reduced platelet production due to in utero chronic hypoxia, was the main finding of most studies focusing on growth-restricted neonates, in most cases is mild and usually resolves spontaneously with the first 2 weeks of life. In regard to coagulation, growth-restricted newborns present with prolonged standard coagulation tests. Data regarding coagulation factors, fibrinolytic system, and anticoagulant proteins are scarce and conflicting, mainly due to confounding factors. As thromboelastography/rotational thromboelastometry (TEG/ROTEM) provides a more precise evaluation of the in vivo coagulation process compared with standard coagulation tests, its use in transfusion guidance is fundamental. Only one study regarding TEG/ROTEM was retrieved from this population, where no difference in ROTEM parameters compared with appropriate for gestational age neonates was found. Despite the laboratory aberrations, no correlation could be achieved with clinical manifestations of bleeding or thrombosis in the studies included. More studies are needed to assess hemostasis in IUGR neonates and guide targeted therapeutic interventions.

Hemostatic Profile of Intrauterine Growth-Restricted Neonates: Assessment with the Use of NATEM Assay in Cord Blood Samples

BACKGROUND

Intrauterine growth restriction (IUGR) is associated with hemorrhagic and thrombotic complications during the perinatal period. Thrombocytopenia, platelet dysfunction, and prolonged standard coagulation tests are observed in this population. The aim of this study is to examine the hemostatic profile of IUGR neonates with the use of a non-activated assay (NATEM) in cord blood samples.

METHODS

During an 18 month period, a NATEM ROTEM assay was performed on cord blood samples of 101 IUGR neonates. A total of 189 appropriate for gestational age (AGA) neonates were used as a control group. The NATEM variables recorded include the following: clotting time (CT); clot formation time (CFT); clot amplitude at 5, 10, and 20 min (A5, A10, A20); α-angle (a°); maximum clot firmness (MCF); lysis index at 30 and 60 min (LI30, LI60); and maximum clot elasticity (MCE).

RESULTS

IUGR neonates demonstrate a hypocoagulable state, with lower A5, A10, A2, MCF, and MCE values when compared to AGA. Using multiple linear regression, we determined IUGR as an independent factor influencing all NATEM parameters (except CT and LI30) exhibiting a hypocoagulable and hypofibrinolytic profile. Platelet count was positively correlated with A5, A10, A20, MCF, alpha angle, and MCE, and negatively correlated with CFT.

CONCLUSION

IUGR neonates appear with lower clot strength and elasticity and prolonged clot kinetics, as illustrated by ROTEM variables.

Coagulation parameters in very preterm infants

The aim of this study was to define normal percentile values of coagulation parameters in preterm infants below 32 weeks of gestational age. This retrospective cohort study was conducted at Istanbul Medical Faculty. Preterm infants who were born prior to 32 weeks of gestation, between 2011 and 2021 were included and evaluated for coagulation parameters. Blood samples obtained through umbilical catheters prior to administration of heparinized flushes/fluids, vitamin K or fresh frozen plasma (FFP). Infants with a major bleeding disorder, intrapartum asphyxia or a history of familial bleeding disorders were excluded. Infants were grouped according to their gestational ages and birth weights: less than 24, 25-26, 27-28, 29-30, 31-32 weeks and <500, 500-749, 750-999, 1000-1249, 1250-1499, more than 1500 g. Third to 97th percentile values of both prothrombin time (PT) and activated partial thromboplastin time (aPTT) were defined. A total of 420 preterm infants were included. The median value and range of gestational age and birth weight of the infants were 29 (22.3-32.9) weeks and 1150 (395-2790) g, respectively. PT values were similar between subgroups according to gestational age but longer in infants with a birth weight less than 1000 g. aPTT values in infants born less than 24 weeks of gestation were found significantly longer. As maturation of the coagulation system increases by gestational age, very preterm infants (<32 gestational week (GW)) are under increased risk of bleeding. Determination of normal percentile distribution of coagulation parameters for preterm infants will shed light on the interpretation of coagulation parameters of these infants and minimize unnecessary FFP administrations.

Reduced platelet function in preterm neonates compared with term neonates

Background

A reduced platelet function might contribute to the longer bleeding time seen in preterm neonates. However, the previously used platelet function testing in neonates is limited due to methodological limitations, mainly caused by difficulties in obtaining adequate blood volume. Therefore, the platelet function in preterm neonates is sparsely investigated. The aim of this study was to compare platelet function in preterm neonates at birth and at expected term age with platelet function in term neonates at birth.

Methods

We included 43 preterm neonates born at gestational age (GA) 28 + 0 to 34 + 0 and 21 term neonates born at GA 38 + 0 to 41 + 0. Within the first 24 hours of life, 1-1.5 mL peripheral blood was obtained and for preterm neonates, resampling was performed at expected term age (GA 38 + 0 to 41 + 0). Platelet function testing included impedance aggregometry and platelet activation measured by flow cytometry. In addition, platelet count was determined.

Results

Platelet count and platelet activation were reduced in preterm neonates compared with term neonates at birth, but we found no difference in impedance aggregometry at birth. At expected term age, platelet count and aggregation exceeded term levels, but platelet activation remained impaired in the preterm.

Conclusion

Preterm neonatal function is decreased at birth and does not seem to reach term levels during the first 4 to 13 weeks of life.

Intraventricular Hemorrhage in Premature Infants: A Historical Review

Intraventricular hemorrhage (IVH) is common in premature newborns and poses a high risk for morbidity with lifelong disability. We searched the available literature for original and secondary literature regarding the epidemiology, pathogenesis, and treatment of IVH in order to trace changes in the management of this disease over time. We examined IVH pathogenesis and epidemiology and reviewed the history of medical and surgical treatment for intraventricular hemorrhage in preterm children. Initial medical management strategies aimed at correcting coagulopathy and eventually targeted mediators of perinatal instability including respiratory distress. Surgical management centered around cerebrospinal fluid diversion, initially through serial lumbar punctures, progressing to ventriculoperitoneal shunting, with more recent interventions addressing intraventricular clot burden. We provide a historical review of the evolution of treatment for IVH in newborns. While the management of IVH has grown significantly over time, IVH remains a common neurosurgical disease that continues to affect patient and caregiver quality of life and health care costs. Despite advances in treatment over more than a century, IVH remains a significant cause of morbidity and mortality in premature infants, and an understanding of past approaches may inform the development of new treatments.

Risk factors for severity of thrombocytopenia in full term infants: a single center study

Background

Neonatal thrombocytopenia (NT) (platelet count < 150 × 10⁹/L) is a common finding in the neonatal intensive care unit (NICU). The main aim of this study was to assess the prevalence, risk factors, and outcomes of severe NT in full term (FT) infants.

Methods

During the study period, all FT infants who met the inclusion criteria for NT on two occasions were included. Maternal data, such as maternal age, weight, gestational age, mode of delivery, and history of systemic diseases, including diabetes mellitus, pre-eclampsia, systemic lupus erythematosus, and immune thrombocytopenic purpura, were recorded. Furthermore, neonatal data, such as gender, neonatal weight, causes/duration of admission, types of respiratory support used, complete blood count measurements, and outcomes for neonates admitted to the NICU, were recorded.

Results

In total, 55 FT infants with NT met the inclusion criteria, and 29 (52.73%) cases had severe NT. The most common cause of NT was neonatal sepsis (20 cases, 36.35%), followed by a postoperative state (5 cases, 9.09%). Moreover, in cases of positive blood cultures, the most commonly isolated organism was Escherichia coli (6 cases, 10.90%), followed by Klebsiella (5 cases, 9.09%). Cases of severe NT needed more platelet transfusions (P = 0.001) and had higher rates of mortality (P = 0.001) when compared to cases of mild/moderate NT associated with signs of bleeding and pulmonary/intraventricular hemorrhage (IVH) (P = 0.001).

Conclusion

Severe NT compared to mild/moderate NT, associated with signs of bleeding and pulmonary/IVH, needed more platelet transfusions, and had increased mortality. Further research is needed to explain which of these complications related to severity of thrombocytopenia or were associated with original disease of the babies.

Intraventricular Hemorrhage in Very Preterm Infants: A Comprehensive Review

Germinal matrix-intraventricular-intraparenchymal hemorrhage (GMH-IVH-IPH) is a major complication of very preterm births before 32 weeks of gestation (WG). Despite progress in clinical management, its incidence remains high before 27 WG. In addition, severe complications may occur such as post-hemorrhagic hydrocephalus and/or periventricular intraparenchymal hemorrhage. IVH is strongly associated with subsequent neurodevelopmental disabilities. For this review, an automated literature search and a clustering approach were applied to allow efficient filtering as well as topic clusters identification. We used a programmatic literature search for research articles related to intraventricular hemorrhage in preterms that were published between January 1990 and February 2020. Two queries ((Intraventricular hemorrhage) AND (preterm)) were used in PubMed. This search resulted in 1093 articles. The data manual curation left 368 documents that formed 12 clusters. The presentation and discussion of the clusters provide a comprehensive overview of existing data on the pathogenesis, complications, neuroprotection and biomarkers of GMH-IVH-IPH in very preterm infants. Clinicians should consider that the GMH-IVH-IPH pathogenesis is mainly due to developmental immaturity of the germinal matrix and cerebral autoregulation impairment. New multiomics investigations of intraventricular hemorrhage could foster the development of predictive biomarkers for the benefit of very preterm newborns.

Effects of small for gestational age status on mortality and major morbidities in ≤750 g neonates

BACKGROUND

Controversy exists regarding the impact of small for gestational age (SGA = birth weight < 10th percentile) status on mortality and major morbidities.

AIM

To assess the effects of SGA on mortality and major morbidities in ≤750 gram (g) neonates.

STUDY DESIGN

Retrospective (01/2005-12/2017), single center study at a tertiary NICU.

SUBJECTS

SGA neonates ≤ 750 g.

OUTCOME

Effect of SGA status on mortality and major morbidities.

RESULTS

183 infants were enrolled. 103 (56.3%) were non-SGA (mean gestational age 25 + 1 weeks ± 9.9 days, mean birth weight 662.6 ± 75.2 g), and 80 (43.7%) SGA (mean gestational age 26 + 6 weeks ± 14.0 days, mean birth weight 543.9 ± 114.7 g). Mortality was 24.1% (non-SGA: 30/103 (29.1%), SGA: 14/80 (17.5%); p = 0.08). Univariable logistic regression analysis revealed a significant protective effect of SGA status on pneumothoraces (OR 0.28, 95%-CI [0.11-0.69]), IVH (≥3) (OR 0.38; 95%-CI [0.15-0.67]), and seizures (OR 0.09, 95%-CI [0.01-0.76]), but NEC (≥2a) occurred more frequently in SGA neonates (p = 0.024). Multiple logistic regression analysis found SGA status to negatively influence ROP (≥3) (OR 2.87, 95%-CI [1.14-7.23]) and need for home monitoring (OR 2.38, 95%-CI [1.05-5.41]). Other major morbidities (IVH, PVL, RDS, BPD, NEC, FIP, sepsis, hearing impairment) and mortality rates were not significantly affected, but distinct organ-specific patterns were seen.

CONCLUSION

SGA had negative effects on the rate of severe ROP and the need for home monitoring, but other major morbidities as well as mortality rates were not significantly affected. In the future, it will be important to delineate underlying pathophysiological mechanisms that contribute to this pattern.

Machine learning models for identifying preterm infants at risk of cerebral hemorrhage

Intracerebral hemorrhage in preterm infants is a major cause of brain damage and cerebral palsy. The pathogenesis of cerebral hemorrhage is multifactorial. Among the risk factors are impaired cerebral autoregulation, infections, and coagulation disorders. Machine learning methods allow the identification of combinations of clinical factors to best differentiate preterm infants with intra-cerebral bleeding and the development of models for patients at risk of cerebral hemorrhage. In the current study, a Random Forest approach is applied to develop such models for extremely and very preterm infants (23-30 weeks gestation) based on data collected from a cohort of 229 individuals. The constructed models exhibit good prediction accuracy and might be used in clinical practice to reduce the risk of cerebral bleeding in prematurity.

Development and validation of a novel scoring system to predict severe intraventricular hemorrhage in very low birth weight infants

OBJECTIVE

We sought to develop and validate a novel scoring system for the prediction of severe intraventricular hemorrhage (SIVH) in very low birth weight infants (VLBWI).

METHODS

This retrospective cohort multicenter study included 615 VLBWI born between 24 and 32 weeks gestational age (GA). Multivariable logistic regression analyses were used to determine which factors evaluated within the first 5 days of life were associated with SIVH and the weights of these variables. The accuracy of the predictive scoring system was prospectively tested in the same units.

RESULTS

The final SIVH scoring system included the following variables: antenatal steroid therapy, GA, birth weight (BW), 1-min Apgar score, mechanical ventilation and hypotension. The SIVH scores used to divide the subjects into three tiers (low-risk (<5), moderate-risk (5-8) and high-risk (>8)) were developed based on these variables. Of infants with a score below 5, 1.2% (4/339) developed SIVH. Of those with a score above 8, 42.5% (17/40) developed SIVH. The scores were successfully verified in 99 VLBWI.

CONCLUSIONS

These findings suggest that among infants with a score >8, the incidence of SIVH is significantly higher. This scoring system can be used to predict the incidence of SIVH during the first 5 days after birth and may contribute to the early intervention in and prevention of SIVH.

Hemostatic profile of infants with spontaneous prematurity: can we predict intraventricular hemorrhage development?

Background

Defining hemostatic profile for preterm infants is a challenge when severe bleedings are frequent.

Methods

The aim was to define the hemostatic profile at birth of infants with spontaneous prematurity and to evaluate whether characteristic profiles can predict the development of intraventricular hemorrhage (IVH) in prematures.

Results

We included 122 newborns with a median age of 31^5/7 gestational age (GA) [29^2/7;34^0/7] and median weight of 1145 g [785;1490]. Levels of fibrinogen, factor II (FII) and factor V (FV) rose with GA (p = 0.017,p = 0.009, p = 0.001). In the group of 23^0/7 – 28^6/7 GA, the 5th percentile was defined as 0.6 g/L for fibrinogen, 15 IU/dL for FII and 16 IU/dL for factor V (n = 30). In the group of 29^0/7–32^6/7 GA, the 5th percentile was defined as 1.0 g/L for fibrinogen, 24 IU/dL for FII and 41 IU/dL for factor V (n = 46). In the group of 33^0/7–36^6/7 GA, the 5th percentile was defined as 1.0 g/L for fibrinogen, 24 IU/dL for FII and 30 IU/dL for factor V (n = 46). Level of fibrinogen was higher in case of vaginal delivery and lower in case of IUGR. Only lower level of FV at birth was significantly associated with IVH (63.5 [46.0; 76.5] vs 74.0 [58.0; 89.0], p = 0.026) with an unadjusted OR per SD increase in FV of 0.57 (95%CI, 0.34 to 0.96). After adjustment for age, the association between FV level and IVH was slightly attenuated (adjusted OR, 0.70; 95%CI, 0.40 to 1.23) but remained not significant (p = 0.22).There was no correlation with FII and fibrinogen.

Conclusions

We can define hemostastic profile of prematures and corroborate references ranges for studied parameters. Further large studies are still called for, to correlate the grade of hemorrhage and the factor V level at birth.

Elevated International Normalized Ratio (INR) is Associated With an Increased Risk of Intraventricular Hemorrhage in Extremely Preterm Infants

INTRODUCTION

The international normalized ratio (INR), a standardized method of reporting the prothrombin time, can be a surrogate marker of the vitamin K-dependent coagulation pathways.

OBJECTIVE

To evaluate the relationship between INR measurements in the first 48 hours of life and subsequent development of intraventricular hemorrhage (IVH) in extremely preterm infants.

MATERIALS AND METHODS

A single-center retrospective, observational cohort study of infants born at <28 weeks gestation. The main outcome measure was defined as the degree of IVH seen on cranial ultrasound examinations at day 7 postnatal age.

RESULTS

Of 200 infants, 109 (mean gestational age, 25.2 wk [SD, 1.27]) had coagulation results available. Of 109, 26 developed IVH. Elevated INR was associated with increased risk of a severe IVH (odds ratio [OR] 6.50; 95% confidence interval [CI], 1.65-25.62; P=0.008) adjusted for gestation, birth weight, and sex. INR was significantly associated with severe IVH in infants who did not receive blood products (OR, 64.60; 95% CI, 1.35-3081.25; P=0.035), but not in those who did (OR, 2.93; 95% CI, 0.67-12.71; P=0.151) (Pinteraction=0.086).

CONCLUSION

An elevated INR in the first 48 hours of life may be useful to identify preterm infants at risk of severe IVH and may guide strategies to prevent the development, or limit the extension, of IVH.

Platelet-Neutrophil Interactions Are Lower in Cord Blood of Premature Newborns

OBJECTIVE

To quantify platelet-neutrophil interaction by flow cytometry, in newborn cord blood, as a function of gestational age.

RATIONALE

Little is known about platelet function markers in the newborn, and developmental variations in these markers are not well described.

METHODS

Cord blood samples were obtained from 64 newborns between 23 and 40 weeks' gestation. The neonates were grouped into three categories: preterm (< 34 weeks' gestation, n = 21), late preterm (34 to < 37 weeks' gestation, n = 22), and term (≥37 weeks' gestation, n = 21). We monitored the expression of P-selectin and the formation of platelet-neutrophil aggregates (PNAs) by flow cytometry while using adenosine 5'-diphosphate (ADP) or thrombin receptor-activating peptide (TRAP) as agonists.

RESULTS

PNAs were significantly lower in preterm compared to term neonates after TRAP or ADP stimulations (11.5 ± 5.2% vs. 19.9 ± 9.1%, p < 0.001, or 24.0 ± 10.1% vs. 39.1 ± 18.2%, p = 0.008, respectively). The expression of P-selectin also tended to be lower in preterm neonates, with significant positive correlations between P-selectin expression and PNA formation.

CONCLUSIONS

The potential formation of PNAs correlates with gestational age. This suggests that the development of functional competencies of platelets and neutrophils continues throughout gestation, progressively enabling interactions between them.

Preterm brain injury: Germinal matrix-intraventricular hemorrhage and post-hemorrhagic ventricular dilatation

Germinal matrix hemorrhage and intraventricular hemorrhages (GMH-IVH) remain a common and clinically significant problem in preterm infants, particularly extremely preterm infants. A large GMH-IVH is often complicated by posthemorrhagic ventricular dilation (PHVD) or parenchymal hemorrhagic infarction and is associated with an increased risk of adverse neurologic sequelae. The widespread use of cranial ultrasonography since the early 1980s has shown a gradual decrease in the incidence of GMH-IVH and has helped with the identification of antenatal and perinatal risk factors and timing of the lesion. The increased use of magnetic resonance imaging (MRI) has contributed to more detailed visualization of the site and extent of the GMH-IVH. In addition, MRI has contributed to the awareness of associated white matter changes as well as associated cerebellar hemorrhages. Although GMH-IVH and PHVD still cannot be prevented, cerebrospinal fluid drainage initiated in the early stage of PHVD development seems to be associated with a better neurodevelopmental outcome. Further studies are underway to improve treatment strategies for PHVD and to potentially prevent and repair GMH-IVH and PHVD and associated brain injury. This chapter discusses the pathogenesis, incidence, risk factors, and management, including preventive measures, of GHM-IVH and PHVD.

Ante-, peri- and postnatal factors associated with intraventricular hemorrhage in very premature infants

BACKGROUND

Intraventricular hemorrhage (IVH) is one of the most serious complications in preterm infants and is associated with neurological sequelae and mortality. Over the past few decades, the rate of IVH has decreased due to improved neonatal intensive care. However, up to 15-25% of very and extremely premature infants (<32 and <28weeks of pregnancy (WOP) respectively) still suffer from IVH.

STUDY PURPOSE

The aim of this study was to perform an updated, multicenter analysis to identify ante-, peri, and postnatal factors other than gestational age/birth weight associated with IVH of any grade in a large cohort of very and extremely premature infants.

METHODS

We performed a retrospective analysis in a prospectively conducted multicenter cohort study between 01/01/1998-31/12/2012 at 5 level 3 perinatal centers. All relevant ante-, peri- and neonatal data were collected and univariate as well as multivariate logistic regression analysis was performed.

RESULTS

765 inborn infants with a gestational age<32 WOP were enrolled into this study (369 (48.2%) female; 396 (51.8%) male). Birth weight ranged from 315g to 2200g (mean 1149.7g, SD 371.9g); 279 (36.5%) were born ≤27+6 WOP and 486 (63.5%)≥28+0 WOP. IVH was seen in 177 (23.1%) patients. Multivariate analysis revealed that in addition to higher gestational age (OR 0.7, CI [0.6-0.8]), antenatal steroid treatment (OR 0.3, CI [0.2-0.6]) and caesarian section without uterine contraction (OR 0.6, CI [0.4-0.9]) were associated with a lower rate of IVH while RDS (OR 5.6, CI [1.3-24.2]), pneumothorax (OR 2.8, CI [1.4-5.5]) and use of catecholamines (OR 2.7, CI [1.7-4.5]) were associated with an increased risk of IVH. After exclusion of gestational age and birth weight from multivariate analysis, early onset sepsis (OR 1.6, CI [1.01-2.7]) and patent ductus arteriosus (OR 1.9, CI [1.1-3.1]) were associated with a higher rate of IVH. In addition, univariate analysis revealed that Apgar scores at 5min (p<0.001), BDP/ROP/NEC (p<0.001), mechanical ventilation (p<0.001) and inhalative nitric oxide (p<0.001) were significantly associated with IVH.

CONCLUSIONS

Our comprehensive analysis demonstrated that the occurrence of IVH in very premature infants is significantly associated with ante-, peri- and postnatal factors being either related to the degree of immaturity or indicating a critical clinical course after birth. The analysis reiterates the necessity for a very close cooperation between obstetricians and neonatologists to reduce the incidence of IVH in this susceptible cohort.

Fresh frozen plasma transfusion - a risk factor for pulmonary hemorrhage in extremely low birth weight infants?

AIM

To evaluate risk factors for pulmonary hemorrhage (PH) in extremely low birth weight infants (ELBW) taking into consideration coagulation screens, platelet counts, transfusion of fresh frozen plasma (FFP), and platelet concentrates prior to PH.

PATIENTS AND METHODS

A retrospective case-control study consisting of 20 ELBW infants with PH and 40 matched controls. Coagulation screens, platelet counts at birth and at onset of PH, and transfusion frequencies prior to PH were compared to case-controls at birth and 24-96 h after birth.

RESULTS

While the initial platelet counts, fibrinogen concentrations, and international normalized ratios were similar in PH infants and controls, the activated partial prothrombin time was prolonged (P=0.05). Compared to 28% of case controls (P<0.05), 55% of infants with later PH received FFP prior to PH. Platelet counts were significantly lower at onset of PH (median 81/nL; range: 37-236/nL) compared to controls (166/nL; 27-460/nL; P<0.005). Multivariate analysis indicated a lack of antenatal steroids, supplemental oxygen, and transfusion of FFP as independent risk factors for PH.

CONCLUSION

Prolonged activated partial thromboplastin time (aPTT) might be associated with PH. PH does not primarily depend upon severe thrombocytopenia. A developmental mismatch in hemostasis by transfusion of adult donor plasma should be considered a risk factor for PH.

Reference values for nucleated red blood cells and serum lactate in very and extremely low birth weight infants in the first week of life

STUDY PURPOSE

To provide reference values for nucleated red blood cells and serum lactate concentrations in very and extremely low birth weight (VLBW/ELBW) infants in the first week of life.

PATIENTS AND METHODS

Retrospective data analysis of serial, daily measurements of NRBC counts and serum lactate during the first 6days of life in VLBW and ELBW infants.

RESULTS

In total, 250 infants<1500g were included in this study. Intrauterine growth retardation (IUGR) was seen in 87 (34.8%) patients. Gestational age (GA) ranged from 23 to 35weeks (mean 29.0weeks) and birth weight (BW) was 320-1499g (mean 1047.9g). During hospital stay, 55 (22%) patients developed IVH and 55 children (22%) BPD. PVL was seen in 12 (4.8%) cases, ROP in 93 (37.2%) and NEC in only 1 (0.4%) patient. NRBC counts as well as serum lactate concentrations depended significantly on birth weight (p<0.01) and presence respectively absence of IUGR (p<0.01). Both NRBC counts and serum lactate concentrations declined constantly during the 6-day period (p<0.01), and both were highly inter-correlated (p<0.01).

CONCLUSIONS

This is one of only a very few studies that systematically and serially evaluated both NRBC counts and serum lactate concentration in VLBW and ELBW infants in the first 6days of life. Both parameters were significantly dependent on birth weight and the presence of IUGR. Moreover, a significant correlation between NRBC counts and serum lactate concentrations in this early period of life could be demonstrated. In future studies, the role of these readily available biomarkers in predicting important neonatal outcome parameters needs to be evaluated in a prospective manner.

Antenatal Betamethasone: A Prolonged Time Interval from Administration to Delivery Is Associated with an Increased Incidence of Severe Intraventricular Hemorrhage in Infants Born before 28 Weeks Gestation

OBJECTIVE

To examine the effects of antenatal steroids on severe intraventricular hemorrhage (IVH) in infants born during the IVH vulnerable period (<28 weeks gestational age) and to evaluate rates of IVH correlated with the time interval between treatment or retreatment and birth.

STUDY DESIGN

A total of 429 infants (<28 weeks gestation), who delivered ≥24 hours after the first betamethasone (BMZ) course (2 doses), were divided into groups based on the interval between the first course of BMZ and delivery: <10 days or ≥10 days. The primary outcome was severe IVH. Multiple regression analyses were performed to adjust for potential confounders.

RESULTS

Three hundred ninety-two infants delivered after a single BMZ course (312 delivered <10 days; 80 ≥10 days). The incidence of severe IVH was 17% for infants delivered ≥10 days and 7% for those delivered <10 days after a single BMZ course (aOR 4.16; 95% CI 1.59-10.87, P = .004); 37 infants (born ≥10 days from the first BMZ course) received a second/rescue BMZ course. The incidence of severe IVH among infants receiving a second/rescue course was 8%, which was similar to the incidence among infants born <10 days (aOR 1.7; 95% CI 0.41-6.6, P = .48).

CONCLUSIONS

In infants born before 28 weeks gestation, delivery ≥10 days from the first BMZ course is associated with a higher incidence of severe IVH; a second/rescue course may reverse this effect.