Severity of abruptio placentae and neurodevelopmental outcome in low birth weight infants

Placental abruption and risk for intraventricular hemorrhage in very low birth weight infants: the United States national inpatient database

OBJECTIVE

To examine the association of placental abruption with intraventricular hemorrhage (IVH) in very low birth weight (VLBW) infants.

METHODS

We examined the National Inpatient Sample (NIS) datasets. Preterm infants <1500 g birth weight (BW) were included. The odds ratios (OR) of developing IVH and severe IVH in association with placental abruption were calculated. Adjusted OR (aOR) were calculated using logistic regression models.

RESULTS

The study included 113,445 VLBW infants. IVH occurred in 18.7% in the infants who were born to mothers with history of placental abruption versus 14.7% in infants without placental abruption, aOR 1.25 (95%CI: 1.13-1.38), p < 0.001. Severe IVH occurred in 6.4% in infants born to mothers with history of placental abruption versus 4.0% in those without placental abruption, aOR 1.53 (95%CI: 1.30-1.78), p < 0.001.

CONCLUSION

Placental abruption is associated with increased prevalence of IVH and severe IVH in VLBW infants.

Placental abruption at near-term and term gestations: pathophysiology, epidemiology, diagnosis, and management

Placental abruption is the premature separation of the placenta from its uterine attachment before the delivery of a fetus. The clinical manifestations of abruption typically include vaginal bleeding and abdominal pain with a wide variety of abnormal fetal heart rate patterns. Clinical challenges arise when pregnant people with this condition present with profound vaginal bleeding, necessitating urgent delivery, especially when there is a concern for maternal and fetal compromise and coagulopathy. Abruption occurs in 0.6% to 1.2% of all pregnancies, with nearly half of abruption occurring at term gestations. An exposition of abruption at near-term (defined as the late preterm period from 34 0/7 to 36 6/7 weeks of gestation) and term (defined as ≥37 weeks of gestation) provides unique insights into its direct effects, as risks associated with preterm birth do not impact outcomes. Here, we explore the pathophysiology, epidemiology, and diagnosis of abruption. We discuss the interaction of chronic processes (decidual and uteroplacental vasculopathy) and acute processes (shearing forces applied to the abdomen) that underlie the pathophysiology. Risk factors for abruption and strengths of association are summarized. Sonographic findings of abruption and fetal heart rate tracings are presented. In addition, we propose a management algorithm for acute abruption that incorporates blood loss, vital signs, and urine output, among other factors. Lastly, we discuss blood component therapy, viscoelastic point-of-care testing, disseminated intravascular coagulopathy, and management of abruption complicated by fetal death. The review seeks to provide comprehensive, clinically focused guidance during a gestational age range when neonatal outcomes can often be favorable if rapid and evidence-based care is optimized.

The Association of Placental Abruption and Pediatric Neurological Outcome: A Systematic Review and Meta-Analysis

Placental histopathology provides insights, or "snapshots", into relevant antenatal factors that could elevate the risk of perinatal brain injury. We present a systematic review and meta-analysis comparing frequencies of adverse neurological outcomes in infants born to women with placental abruption versus without abruption. Records were sourced from MEDLINE, Embase, and the CENTRAL Trials Registry from 1946 to December 2019. Studies followed the PRISMA guidelines and compared frequencies of neurodevelopmental morbidities in infants born to pregnant women with placental abruption (exposure) versus women without placental abruption (comparator). The primary endpoint was cerebral palsy. Periventricular and intraventricular (both severe and any grades of IVH) and any histopathological neuronal damage were the secondary endpoints. Study methodologic quality was assessed by the Ottawa-Newcastle scale. Estimated odds ratios (OR) and hazards ratio (HR) were derived according to study design. Data were meta-analyzed using a random effects model expressed as pooled effect sizes and 95% confidence intervals. We included eight observational studies in the review, including 1245 infants born to women with placental abruption. Results of the random effects meta-analysis show that the odds of infants born to pregnant women with placental abruption who experience cerebral palsy is higher than in infants born to pregnant women without placental abruption (OR 5.71 95% CI (1.17, 27.91); I² = 84.0%). There is no statistical difference in the odds of infants born to pregnant women with placental abruption who experience severe IVH (grade 3+) (OR 1.20 95% CI (0.46, 3.11); I² = 35.8%) and any grade of IVH (OR 1.20 95% CI (0.62, 2.32); I² = 32.3%) vs. women without placental abruption. There is no statistically significant difference in the odds of infants born to pregnant women with placental abruption who experience PVL vs. pregnant women without placental abruption (OR 6.51 95% CI (0.94, 45.16); I² = 0.0%). Despite our meta-analysis suggesting increased odds of cerebral palsy in infants born to pregnant women with placental abruption versus without abruption, this finding should be interpreted cautiously, given high heterogeneity and overall poor quality of the included studies.

Placental pathology: Pathways leading to or associated with perinatal brain injury in experimental neurology, special issue: Placental mediated mechanisms of perinatal brain injury

Perinatal brain injury is a multifactorial process. In utero placental physiology plays a major role in neuroprotection and the normal development of the fetal central nervous system. Advances in placental pathology have clarified several specific mechanisms of injury and the histologic lesions most strongly associated with them. This review provides an updated summary of the relevant placental anatomy and physiology, the specific placental pathways leading to brain injury, the revised Amsterdam classification system for placental pathology, and the known associations of specific placental lesions with subtypes of adverse neurologic outcomes.

Risk Factors for Periventricular Leukomalacia in Preterm Infants: A Systematic Review, Meta-analysis, and GRADE-Based Assessment of Certainty of Evidence

BACKGROUND

We analyzed the certainty of evidence (CoE) for risk factors of periventricular leukomalacia (PVL) in preterm neonates, a common morbidity of prematurity.

METHODS

Medline, CENTRAL, Embase, and CINAHL were searched. Cohort and case-control studies and randomised randomized controlled trials were included. Data extraction was performed in duplicate. A random random-effects meta-analysis was utilizedused. CoE was evaluated as per Grading of Recommendations Assessment, Development and Evaluation (GRADE) guidelines.

RESULTS

One hundred eighty-six studies evaluating 95 risk factors for PVL were included. Of the 2,509,507 neonates assessed, 16,569 were diagnosed with PVL. Intraventricular hemorrhage [adjusted odds ratio: 3.22 (2.52-4.12)] had moderate CoE for its association with PVL. Other factors such as hypocarbia, chorioamnionitis, PPROM >48 hour, multifetal pregnancy reduction, antenatal indomethacin, lack of antenatal steroids, perinatal asphyxia, ventilation, shock/hypotension, patent ductus arteriosus requiring surgical ligation, late-onset circulatory collapse, sepsis, necrotizing enterocolitis, and neonatal surgery showed significant association with PVL after adjustment for confounders (CoE: very low to low). Amongst the risk factors associated with mother placental fetal (MPF) triad, there was paucity of literature related to genetic predisposition and defective placentation. Sensitivity analysis revealed that the strength of association between invasive ventilation and PVL decreased over time (P < 0.01), suggesting progress in ventilation strategies. Limited studies had evaluated diffuse PVL.

CONCLUSION

Despite decades of research, our findings indicate that the CoE is low to very low for most of the commonly attributed risk factors of PVL. Future studies should evaluate genetic predisposition and defective placentation in the MPF triad contributing to PVL. Studies evaluating exclusively diffuse PVL are warranted.

Relation of outbursts of anger and the acute risk of placental abruption: A case-crossover study

BACKGROUND

Roughly, a fourth of all placental abruption cases have an acute aetiologic underpinning, but the causes of acute abruption are poorly understood. Studies indicate that symptoms of stress, depression, and anxiety during pregnancy may be associated with a higher risk of abruption.

OBJECTIVE

We examined the rate of abruption in the 2 hours immediately following outbursts of anger.

METHODS

In a multicentre case-crossover study, we interviewed 663 women diagnosed with placental abruption admitted to one of the seven Peruvian hospitals between January 2013 and August 2015. We asked women about outbursts of anger before symptom onset and compared this with their usual frequency of anger during the week before abruption.

RESULTS

The rate of abruption was 2.83-fold (95% confidence interval [CI] 1.85, 4.33) higher in the 2 hours following an outburst of anger compared with other times. The rate ratio (RR) was lower for women who completed technical school or university (RR 1.38, 95% CI 0.52, 3.69) compared to women with secondary school education or less (RR 3.73, 95% CI 2.32, 5.99, P-homogeneity = .07). There was no evidence that the association between anger episodes and abruption varied by hypertensive disorders of pregnancy (ie preeclampsia/ eclampsia) or antepartum depressive symptoms.

CONCLUSION

There was a higher rate of abruption in the 2 hours following outbursts of anger compared with other times, providing potential clues to the aetiologic mechanisms of abruption of acute onset.

Physical Exertion Immediately Prior to Placental Abruption: A Case-Crossover Study

While there is consistent evidence that episodes of physical exertion are associated with an immediately higher risk of acute ischemic vascular events, the risk of placental abruption immediately following episodes of physical exertion has not been studied. In a multicenter case-crossover study, we interviewed 663 women with placental abruption at 7 Peruvian hospitals between January 2013 and August 2015. We asked women about physical exertion in the hour before symptom onset and compared this with their frequency of physical exertion over the prior week. Compared with times with light or no exertion, the risk of placental abruption was 7.8 (95% confidence interval (CI): 5.5, 11.0) times greater in the hour following moderate or heavy physical exertion. The instantaneous incidence rate ratio of placental abruption within an hour of moderate or heavy physical exertion was lower for women who habitually engaged in moderate or heavy physical activity more than 3 times per week in the year before pregnancy (rate ratio (RR) = 3.0, 95% CI: 1.6, 5.9) compared with more sedentary women (RR = 17.3, 95% CI: 11.3, 26.7; P for homogeneity < 0.001), and the rate ratio was higher among women with preeclampsia/eclampsia (RR = 13.6, 95% CI: 7.0, 26.2) than among women without (RR = 6.7, 95% CI: 4.4, 10.0; P for homogeneity = 0.07).

Placental Abruption and Child Mortality

BACKGROUND AND OBJECTIVES

Placental abruption causes asphyxia and leads to high perinatal mortality. Our objective was to study the overall mortality and causes of death among children born after placental abruption.

METHODS

Data on children born from singleton pregnancies complicated by placental abruption between 1987 and 2005 were collected from the Finnish Medical Birth Register, the Hospital Discharge Register, and the Cause-of-Death Register. A reference group consisted of children born from pregnancies without placental abruption. After excluding stillbirths, the final study sample comprised 3888 children born after placental abruption (index children) and 12 530 referent children. The main outcome measure was overall mortality.

RESULTS

By the end of 2013, there were 280 deaths among the index children and 107 deaths among the referent children. Compared with the referent children, the overall mortality among the index children was significantly increased (hazard ratio: 8.70; 95% confidence interval 6.96-10.90). During the neonatal period (0-27 days) the mortality was nearly 15-fold (14.8; 10.9-20.0), birth-related asphyxia being the leading cause of death (108; 34-341). The mortality remained high during days 28 to 365 (10.3; 4.83-21.8) and beyond 365 days (1.70; 1.03-2.79). Furthermore, the overall mortality was increased among the index children born at 32 to 36 + 6 gestational weeks (2.77; 1.54-4.98) and at ≥37 weeks (4.98; 3.54-6.99) and among children with a birth weight of 2500 g or more (5.94; 4.33-8.14).

CONCLUSIONS

The impact of abruption on offspring mortality extends far beyond the perinatal period. This is mainly due to birth-related asphyxia and prematurity-related consequences.

The histologic evolution of revealed, acute abruptions

There is considerable interest in using pathology to confirm acute abruptions. It has been suggested that pathologic findings can help to determine the timing of abruptions. Because of the dearth of evidence in the literature supporting this claim and its medicolegal implications, we undertook this study to explore further the possibility of timing abruptions by histopathology. We sought to correlate bleeding interval (duration from maternal presentation with vaginal bleeding [revealed abruption] to placental delivery) with placental histopathologic findings. We performed a retrospective review of clinical data and placental pathology from all cases of clinically diagnosed, acute, revealed abruptions at a single, large institution in New England between 2000 and 2015. Cases were identified based on clinical diagnoses, bleeding intervals were calculated from clinical notes, and histologic evaluations were performed by 2 pathologists blinded to the bleeding intervals. A total of 177 cases were analyzed. Of these, 103 (58%) had histologic findings corroborating the clinical diagnosis of abruption. The most frequent finding was maternal surface indentation (51 cases) followed by intravillous hemorrhage (50 cases). The former was also the earliest finding, with a minimum bleeding interval of 4 minutes. In multivariate modeling, plasma cell deciduitis was significantly associated with a longer bleeding interval (median 63 hours). If there were 2 pathologic findings, there was a trend toward a longer bleeding interval. There was modest sensitivity for the pathologic diagnosis of acute revealed abruption. Although there was not a clear, stepwise progression of histologic lesions; the presence of 2 or more findings tended to be seen with longer bleeding intervals. Our results suggest that histologic findings cannot be used to time acute revealed abruptions reliably, and any interpretation of such should be made with caution.

Maternal Morbidities and Occurrence of Intraventricular Hemorrhage in Preterm Infants

Intraventricular hemorrhage (IVH) is one of the most serious neurological morbidities in preterm infants. Several prenatal, intrapartum, and neonatal risk factors have been detected in different studies. However, maternal conditions that may render the neonates to IVH have been the subject of very few studies. Preterm infants with and without IVH were included in the study, and maternal obstetrics and general health clinical files were reviewed for any kind of morbidity. Data were then analyzed with statistical software to assess the association between maternal conditions and IVH. A total of 115 neonates with IVH and 120 infants without IVH were recruited. Among all maternal conditions, prolonged rupture of membrane (p = 0.00), laparoscopic surgery for infertility (p = 0.001), and in vitro fertilization (IVF) (p = 0.00) increased the risk of IVH in neonates significantly. IVF remained strongly associated with IVH even after controlling for confounding variables (odds ratio: 9.75; confidence interval: 2.66-35.75; p = 0.001). Based on our findings, prolonged rupture of membrane and IVF were maternal conditions that increased the risk of IVH. Laparoscopic surgery for infertility was also associated with an increased risk of IVH.

Change in paternity, risk of placental abruption and confounding by birth interval: a population-based prospective cohort study in Norway, 1967-2009

OBJECTIVES

We examined abruption risk in relation to change in paternity, and evaluated if birth interval confounds this association.

SETTING

Population-based study of singleton births in Norway between 1967 and 2009.

PARTICIPANTS

Women who had their first two (n=747 566) singleton births in the Norwegian Medical Birth Registry. The associations between partner change between pregnancies and birth interval were examined in relation to abruption in a series of logistic regression models.

PRIMARY OUTCOME MEASURES

Risk, as well as unadjusted and adjusted OR of placental abruption in relation to change in paternity and interval between births.

RESULTS

Among women without abruption in their first pregnancy, the risks of abruption in the second pregnancy were 4.7 and 6.5 per 1000 in women who had the same and different partners, respectively (OR=1.39, 95% CI 1.26 to 1.53). After adjustments for confounders including birth interval and smoking, partner change was not associated with abruption (OR=1.01, 95% CI 0.79 to 1.32). Among women with abruption in the first pregnancy, the association between partner change and abruption in the second pregnancy was 0.98 (95% CI 0.75 to 1.28). Interval <1 year was associated with increased abruption risk in the second pregnancy among women with the same as well as different partners, but interval over 4 years was only associated with increased risk among women with the same partner. No such patterns were seen for recurrent abruption.

CONCLUSIONS

We find no evidence that a change in partner is associated with increased abruption risk. Theories supporting an immune maladaptation hypothesis afforded by change in paternity are not supported insofar as abruption is concerned.

Placental genome and maternal-placental genetic interactions: a genome-wide and candidate gene association study of placental abruption

While available evidence supports the role of genetics in the pathogenesis of placental abruption (PA), PA-related placental genome variations and maternal-placental genetic interactions have not been investigated. Maternal blood and placental samples collected from participants in the Peruvian Abruptio Placentae Epidemiology study were genotyped using Illumina's Cardio-Metabochip platform. We examined 118,782 genome-wide SNPs and 333 SNPs in 32 candidate genes from mitochondrial biogenesis and oxidative phosphorylation pathways in placental DNA from 280 PA cases and 244 controls. We assessed maternal-placental interactions in the candidate gene SNPS and two imprinted regions (IGF2/H19 and C19MC). Univariate and penalized logistic regression models were fit to estimate odds ratios. We examined the combined effect of multiple SNPs on PA risk using weighted genetic risk scores (WGRS) with repeated ten-fold cross-validations. A multinomial model was used to investigate maternal-placental genetic interactions. In placental genome-wide and candidate gene analyses, no SNP was significant after false discovery rate correction. The top genome-wide association study (GWAS) hits were rs544201, rs1484464 (CTNNA2), rs4149570 (TNFRSF1A) and rs13055470 (ZNRF3) (p-values: 1.11e-05 to 3.54e-05). The top 200 SNPs of the GWAS overrepresented genes involved in cell cycle, growth and proliferation. The top candidate gene hits were rs16949118 (COX10) and rs7609948 (THRB) (p-values: 6.00e-03 and 8.19e-03). Participants in the highest quartile of WGRS based on cross-validations using SNPs selected from the GWAS and candidate gene analyses had a 8.40-fold (95% CI: 5.8-12.56) and a 4.46-fold (95% CI: 2.94-6.72) higher odds of PA compared to participants in the lowest quartile. We found maternal-placental genetic interactions on PA risk for two SNPs in PPARG (chr3:12313450 and chr3:12412978) and maternal imprinting effects for multiple SNPs in the C19MC and IGF2/H19 regions. Variations in the placental genome and interactions between maternal-placental genetic variations may contribute to PA risk. Larger studies may help advance our understanding of PA pathogenesis.

Ischemic placental disease and risks of perinatal mortality and morbidity and neurodevelopmental outcomes

Preeclampsia, intrauterine growth restriction, and placental abruption are serious obstetrical complications that constitute the syndrome of ischemic placental disease and account for a disproportionate degree of perinatal morbidity and mortality. We review the risks of stillbirth and neonatal and infant mortality in relation to ischemic placental disease, focusing on population-based studies. We also review the risks of neonatal morbidity and neurodevelopmental outcomes in relation to ischemic placental disease. A synthesis of the findings of the relevant studies relating ischemic placental disease to adverse perinatal outcomes underscores two important observations. First, despite the low prevalence of each of the three obstetrical complications, all are associated with increased risks of adverse perinatal and infant outcomes, as well as neurodevelopmental deficits. Second, the burden of increased perinatal risks appears strongest during the preterm period. Efforts to reduce the risks of ischemic placental disease remain critically important and developing effective clinical interventions will be a target worthy for consideration.

Perinatal morbidity and risk of hypoxic-ischemic encephalopathy associated with intrapartum sentinel events

OBJECTIVE

To examine perinatal morbidity and rate of hypoxic-ischemic encephalopathy in infants exposed to intrapartum sentinel events.

STUDY DESIGN

Retrospective cohort study from 2000-2005. Perinatal mortality, perinatal morbidity and rate of hypoxic-ischemic encephalopathy were compared in 3 groups of infants exposed to different risk factors for perinatal asphyxia (sentinel events, nonreassuring fetal status, elective cesarean section).

RESULTS

Five hundred eighty-six infants were studied. Perinatal mortality was 6% in the sentinel event group and 0.3% in the nonreassuring fetal status group (relative risk, 2.4; 95% confidence interval, 1.95-2.94). Perinatal morbidity was 2-6 times more frequent in infants exposed to sentinel events; the incidence of hypoxic-ischemic encephalopathy was 10%, compared with 2.5% in the nonreassuring fetal status group (relative risk, 1.93; 95% confidence interval, 1.49-2.52). No infant in the elective cesarean section group died, had perinatal morbidity, or developed encephalopathy.

CONCLUSION

Intrapartum sentinel events are associated with a high incidence of perinatal morbidity and hypoxic-ischemic encephalopathy.

Placental abruption: epidemiology, risk factors and consequences

Placental abruption, classically defined as a premature separation of the placenta before delivery, is one of the leading causes of vaginal bleeding in the second half of pregnancy. Approximately 0.4-1% of pregnancies are complicated by placental abruption. The prevalence is lower in the Nordic countries (0.38-0.51%) compared with the USA (0.6-1.0%). Placental abruption is also one of the most important causes of maternal morbidity and perinatal mortality. Maternal risks include obstetric hemorrhage, need for blood transfusions, emergency hysterectomy, disseminated intravascular coagulopathy and renal failure. Maternal death is rare but seven times higher than the overall maternal mortality rate. Perinatal consequences include low birthweight, preterm delivery, asphyxia, stillbirth and perinatal death. In developed countries, approximately 10% of all preterm births and 10-20% of all perinatal deaths are caused by placental abruption. In many countries, the rate of placental abruption has been increasing. Although several risk factors are known, the etiopathogenesis of placental abruption is multifactorial and not well understood.

[Cerebral palsy and perinatal asphyxia (I--diagnosis)]

Cerebral palsy (CP) is a group of disorders of the development of movement and posture, causing activity limitations, that are attributed to nonprogressing disturbances that occurred in the developing fetal or infant brain. The motor abnormalies are often accompanied by disturbances of sensation, perception, cognition, behavior and/or by a seizure disorder. The prevalence of CP has not decreased in developed countries over the past 30 years, despite the widespread use of electronic fetal heart rate monitoring and a 5- to 6-fold increase in the cesarean delivery rate. In the term newborn, CP may be attributed to perinatal asphyxia in case of metabolic acidosis in the cord blood (pH<7,00 and base deficit>12 mmol/L), followed by a moderate or severe neonatal encephalopathy within 24 hours and a further neurological impairement characterized by spastic quadriplegia and dyskinesia/dystonia. Dating the time of fetal asphyxia during delivery is possible when there are acute catastrophic complications during labor and unexpected acute or progressive fetal heart rate anomalies after a normal admission test, when there is a need for intensive neonatal resuscitation, a multi-organ failure within 72 hours of birth and visualization of acute non focal cerebral abnormalities, mainly by early magnetic resonance imaging (MRI). MRI sequences show either a brain-damaged pattern of the central basal ganglia, thalami and posterior limbs of internal capsules with relative cortical sparing, in acute, near-total asphyxial insults manifested by a continuous bradycardia or a pattern of cortical injury in the watershed zones and relative sparing of the central grey matter, in prolonged partial asphyxia, manifested by late or atypical variable decelerations with progressive fetal tachycardia, loss of reactivity and absent fluctuation. Prolongation of either type of asphyxial insult results in more global brain damage. In order to differentiate a CP occurring after perinatal asphyxia from other neurological sequelae in relation with infection, hemorrhage, stroke, malformations, genetic or metabolic diseases, it is essential that a definitive information from the brain by MRI and an extensive histological examination of the placenta are at disposal.

Cerebral Palsy and the Application of the International Criteria for Acute Intrapartum Hypoxia

OBJECTIVE

To apply objective criteria for the identification of acute intrapartum hypoxia in a cohort of cerebral palsy cases and to identify other cerebral palsy-related pathologies.

METHODS

A cohort of all 235 neonates with cerebral palsy from a single Australian tertiary care center born between 1986 and 2003. Cases were identified from the South Australian Cerebral Palsy Register. Maternal and pediatric case notes were audited with application of the 2003 American College of Obstetricians and Gynecologists/American Academy of Pediatrics criteria to identify acute intrapartum hypoxia.

RESULTS

Data were available for analysis in 213 cases (91%). Major antenatal or pediatric cerebral palsy-related pathologies were identified in 98.1% of all these cases. An isolated acute intrapartum hypoxic event was defined as likely in only 2 of the 46 neonates born at term and none born preterm. Neonatal nucleated red blood cell counts were often high in neonates born preterm and following antenatal pathologies.

CONCLUSION

Cerebral palsy was seldom preceded by acute intrapartum hypoxia but antenatal cerebral palsy-related pathologies are often detectable. The objective American College of Obstetricians and Gynecologists/American Academy of Pediatrics criteria are useful to audit cerebral palsy causation and exclude primary intrapartum hypoxia.

LEVEL OF EVIDENCE

II-3.

Complications of second and third trimester pregnancies

The second and third trimester of pregnancy is a period of extensive physical growth and maturation of the fetus. Unfortunately, it is also a period that is marked by complications that can be life threatening for both the mother and fetus. The top three complications that affect pregnancy are hemorrhage, infection, and the hypertensive diseases of pregnancy. This article focuses on preterm labor, premature rupture of membranes, chorioamnionitis, bleeding in later pregnancy, and the hypertensive diseases of pregnancy.

Comparison of neonatal outcome including cerebral palsy between abruptio placentae and placenta previa

OBJECTIVE

Our purpose was to evaluate the neonatal prognosis after abruptio placentae and placenta previa during pre-term gestation.

STUDY DESIGN

A case-control study was performed using a logistic regression model. A poor outcome was defined as neonatal death occurring before hospital discharge or a diagnosis of cerebral palsy.

RESULTS

A poor outcome was more frequent in cases of abruptio placentae (11/42, 26.2%) than in placenta previa (2/72, 2.8%) and pre-term labor (1/120, 0.8%). The difference was mainly due to the incidence of cerebral palsy. A significant association of abruptio placentae (odds ratio (OR) 61.0, 95% confidence interval (CI 3.4-1084), delivery at <31 weeks of gestation (OR 19.0, CI 2.8-128.8), and low Apgar score (<7) at 5min (OR 70.8, CI 16.5-304.9) with increased risk of poor outcome was found in the logistic regression model that controlled for confounding effects. In abruptio placentae, a low Apgar score (<7) at 5min (OR 19.8, CI 2.0-197.8) was associated with increased risk of poor outcome in the logistic regression model.

CONCLUSION

From the standpoint of poor perinatal outcome including cerebral palsy, abruptio placentae was the most significant clinical entity in pre-term gestation.

Management of obstetric hemorrhage

A reluctance to proceed with hysterectomy for obstetric hemorrhage may be a more likely cause of preventable death in obstetrics than a lack of surgical or medical skills. Every obstetric unit should have protocols available to deal with hemorrhage and, in addition, have specific guidelines for patients who object to blood transfusions for various reasons. Risk factors for hemorrhage should be identified antenatally, using all possible imaging modalities available, and utilizing multidisciplinary resources whenever possible. Novel strategies for prenatal diagnosis of abnormal placentation include advanced sonography and magnetic resonance imaging. Placement and utilization of arterial catheters for uterine artery embolization is becoming more widespread and new surgical technology such as the argon beam coagulator seems promising. When intra or postpartum hemorrhage is encountered, a familiar protocol for dealing with blood loss should be triggered. Timely hysterectomy should be performed for signs of refractory bleeding. Application of medical and surgical principles combined with recent technologic advances will help the obstetrician avoid disastrous outcomes for both mother and fetus.

Cerebral palsy in very preterm infants: new epidemiological insights

The focus of this review is on new insights from recent epidemiological research on cerebral palsy in preterm infants. These include: 1) a better understanding of issues related to diagnosis and classification; 2) new information about the brain abnormalities underlying cerebral palsy in preterm infants; and 3) a better understanding of biological mechanisms that may underlie previously described epidemiological associations. Ongoing efforts to improve the diagnosis and classification of cerebral palsy have been enhanced by findings from serial examinations of cohorts of very preterm infants. Cranial ultrasonography through the anterior fontanelle of very preterm infants has provided information about grossly evident brain damage, found in about one-half of preterm infants who develop cerebral palsy. Insights into the pathophysiologic basis for certain epidemiologic associations have come from studies of experimental brain damage in animals and clinical studies of neurologic disorders in adults. Much of the current epidemiological research into the causes of cerebral palsy in preterm infants has focused on two potential mechanisms of brain damage. One mechanism involves insufficient cerebral perfusion; the other, cytokine-mediated damage, potentially triggered by events such as maternal infection (e.g., intrauterine or periodontal infection), neonatal infection (e.g., sepsis and necrotizing enterocolitis), and neonatal oxygen- or ventilator-induced lung injury. In addition to the preterm infant's increased exposure to such damaging factors, the high frequency of cerebral palsy in these infants might be due, in part, to insufficient levels of developmentally regulated protective substances, such as thyroid hormone and glucocorticoids. Models of causation currently are being investigated using recently developed methods for quantifying, with small quantities of blood, biomolecules that are suspected to either promote or protect against brain damage in the neonate. Clinical investigations now under way can be expected to identify strategies to be tested in clinical trials that could lower the risk of cerebral palsy in very preterm infants.

Antecedents of cerebral palsy in very low-birth weight infants

Research from the last two decades provides directions for efforts to prevent CP in VLBW infants. The pathogenesis of CP seems to involve factors operating both during pregnancy and in the neonatal period. The most important prenatal factor appears to be intrauterine infection. Perinatal infection and other risk factors, such as the death of a co-twin, placental abruption, and cerebral ischemia, could trigger a cytokine cascade resulting in damage to the developing brain. The low frequency of intrauterine infection in mothers with preeclampsia might explain the apparent protective effect of this disorder. If the brain damage attributed to intrauterine infection and other risk factors involves cytokines as intermediates, then blockade of the proinflammatory cascade or promotion of endogenous inhibitors might prevent CP. Other potentially preventive strategies include corticosteroids given to mothers (but not those given to neonates) and thyroid hormone.

Validation of a cerebral palsy register

OBJECTIVES

To analyse completeness and validity of data in the Cerebral Palsy Register in Denmark, 1979-1982.

METHODS

Completeness has been assessed by comparing data from The Danish National Patient Register (DNPR) with the cases included in the Cerebral Palsy Register (CPR). Agreement between 12 variables in the CPR and obstetrical medical records has been analysed using kappa-statistics.

RESULTS

Of 468 children in the DNPR, only 237 fulfilled the inclusion criteria of the CPR; and 35 (15%) of these cases had not been reported to the CPR. Data agreement was generally good, but gestational age was subject to a systematic error, and urinary infections in pregnancy (kappa = 0.43) and placental abruption (kappa = 0.52) were seriously under-reported in the CPR.

CONCLUSIONS

Completeness of the Cerebral Palsy Register in Denmark, 1979-1982, has been assessed to maximal 85%, emphasizing the impact of using supplementary case ascertainment sources in the future. Validity of data varied according to definition and significance of the specific variable.

Survival and neonatal and neurodevelopmental outcome of 24-29 week gestation infants according to primary cause of preterm delivery

A total of 189 infants of 24-29 weeks' gestation were born in a regional perinatal centre during a 2-year period. They were divided into groups according to the primary cause of preterm delivery: antepartum haemorrhage (n = 37, 20%), preeclampsia (n = 27), 14%), preterm premature rupture of membranes (n = 64, 34%), preterm labour (n = 27, 14%), chorioamnionitis (n = 16, 8%), other complications (n = 18, 10%). The perinatal mortality rate (PMR) was 286/1,000 of whom 44% were stillbirths. The 'other complication' group had the highest PMR due to a large number of intrauterine deaths, with no differences in neonatal mortality between the groups. Preeclampsia was associated with an increased risk of necrotizing enterocolitis and chorioamnionitis was associated with an increased risk of periventricular haemorrhage. Follow-up to at least 2 years was performed in 122 (97%) of survivors. Cerebral palsy occurred in 7%, while 18% had neurodevelopmental disability. No relationship was found between primary cause of preterm delivery and outcome. This information should be of value in counselling parents when preterm delivery is imminent.

Risk factors for cerebral palsy: a case-control study in Greece

The purpose of this study was to investigate the relation between a series of maternal, antenatal, perinatal, socioeconomic and environmental variables and the occurrence of cerebral palsy (CP) in a setting different from those in which previous analytic epidemiologic studies had been undertaken. The study was of case-control design and included 103 children with cerebral palsy born between 1984 and 1988 and residents of the Greater Athens area at any time during 1991 and 1992. Controls were chosen among the neighbors of the index case or were healthy siblings of children with neurological diseases other than CP seen by the same neurologists as the children with CP; a total of 254 control children were eventually included. Statistical analysis was done by modeling the data through unconditional logistic regression. Statistically significant (p < 0.05) risk factors of potential causal importance were: twin membership (OR = 10.2), gestational age (OR = 0.5 per 4 weeks), birth weight conditional on gestational age (OR = 0.9 per 100 g), congenital malformations (OR = 7.5), unhealthy placenta (OR = 6.6), placenta previa (6 cases, no controls), abnormal amniotic fluid (OR = 3.6), head circumference more than 36 cm (OR = 9.0), general anesthesia during labor (OR = 4.3), forceps delivery (OR = 6.8), and birth trauma (OR = 11.5). Among children with no identifiable prenatal risk factors there was no excess prevalence of one or more perinatal risk factors in CP cases compared to controls, which implies that the latter factors impart their effect through interactions with co-existing prenatal or other risk factors.