NSIDRC Journal Article Alert — June 6, 2008

Prepared by the National Sudden Infant Death Resource Center at Georgetown University.

This journal article alert provides selected items added to the National Library of Medicine’s PubMed database in the last week.

Past issues of NSIDRC journal alerts are available at http://www.sidscenter.org.
Availability of full-text journal articles is often limited to subscribers or through inter-library loan. Please see your local library for copies of these articles, or view PubMed's How to Get the Journal Article for more details.

Sudden Infant Death

1. Mitchell EA, Thompson JM, Becroft DM, Bajanowski T, Brinkmann B, Happe A, Jorch G, Blair PS, Sauerland C, Vennemann MM
Head covering and the risk for SIDS: findings from the New Zealand and German SIDS case-control studies
Pediatrics. 2008 Jun;121(6):e1478-83

University of Auckland, Department of Paediatrics, Private Bag 92019, Auckland, New Zealand. e.mitchell@auckland.ac.nz

OBJECTIVES: The aim of this investigation was to identify risk factors for being found with the head covered in sudden infant death syndrome cases and determine whether head covering was likely to be an agonal event or potentially part of the causal pathway in some cases. By using the data from 2 sudden infant death syndrome case-control studies, consistency of the findings could be assessed. METHODS: Two case-control studies were assessed: (1) the New Zealand Cot Death Study (1987-1990, 393 sudden infant death syndrome cases) and (2) a German SIDS case-control study (1998-2001, 333 sudden infant death syndrome cases). RESULTS: The proportion of sudden infant death syndrome cases in which infants were found with their head covered was 15.6% in the New Zealand study and 28.1% in the German study. Being found with head covering was associated with older infant age. In both studies, being found with head covering was associated with being very sweaty when found. Head covering was also associated with the incidence and severity of thymic petechiae in both studies. Both the position in which the child was placed to sleep and the position in which the child was found were not associated with head covering. CONCLUSIONS: The finding that sudden infant death syndrome cases in which infants were found with their heads covered were often very sweaty suggests that head covering was not an agonal event and that it preceded the death and may have been causally related to the death. Infants who were found with their head covered were older, which probably reflects motor development.

Other Infant Death

1. Weber M, Klein Nj, Hartley J, Lock P, Malone M, Sebire Nj
Infection and sudden unexpected death in infancy: a systematic retrospective case review
Lancet. 2008 May 31;371(9627):1848-53

Department of Paediatric Pathology, Great Ormond Street Hospital for Children and the Institute of Child Health, University College London, London, UK.

BACKGROUND: The cause and mechanism of most cases of sudden unexpected death in infancy (SUDI) remain unknown, despite specialist autopsy examination. We reviewed autopsy results to determine whether infection was a cause of SUDI. METHODS: We did a systematic retrospective case review of autopsies, done at one specialist centre between 1996 and 2005, of 546 infants (aged 7-365 days) who died suddenly and unexpectedly. Cases of SUDI were categorised as unexplained, explained with histological evidence of bacterial infection, or explained by non-infective causes. Microbial isolates gathered at autopsy were classified as non-pathogens, group 1 pathogens (organisms usually associated with an identifiable focus of infection), or group 2 pathogens (organisms known to cause septicaemia without an obvious focus of infection). FINDINGS: Of 546 SUDI cases, 39 autopsies were excluded because of viral or pneumocystis infection or secondary bacterial infection after initial collapse and resuscitation. Bacteriological sampling was done in 470 (93%) of the remaining 507 autopsies. 2079 bacteriological samples were taken, of which 571 (27%) were sterile. Positive cultures yielded 2871 separate isolates, 484 (32%) of which showed pure growth and 1024 (68%) mixed growth. Significantly more isolates from infants whose deaths were explained by bacterial infection (78/322, 24%) and from those whose death was unexplained (440/2306, 19%) contained group 2 pathogens than did those from infants whose death was explained by a non-infective cause (27/243, 11%; difference 13.1%, 95% CI 6.9-19.2, p<0.0001 vs bacterial infection; and 8.0%, 3.2-11.8, p=0.001 vs unexplained). Significantly more cultures from infants whose deaths were unexplained contained Staphylococcus aureus (262/1628, 16%) or Escherichia coli (93/1628; 6%) than did those from infants whose deaths were of non-infective cause (S aureus: 19/211, 9%; difference 7.1%, 95% CI 2.2-10.8, p=0.005; E coli: 3/211, 1%, difference 4.3%, 1.5-5.9, p=0.003). INTERPRETATION: Although many post-mortem bacteriological cultures in SUDI yield organisms, most seem to be unrelated to the cause of death. The high rate of detection of group 2 pathogens, particularly S aureus and E coli, in otherwise unexplained cases of SUDI suggests that these bacteria could be associated with this condition. FUNDING: Foundation for the Study of Infant Deaths.

2. Kung HC, Hoyert DL, Xu J, Murphy SL
Deaths: final data for 2005
Natl Vital Stat Rep. 2008 Apr 24;56(10):1-120

Division of Vital Statistics, U.S. Department of Health and Human Services, National Center for Health Statistics, Centers for Disease Control and Prevention, Hyattsville, MD 20782, USA

OBJECTIVES: This report presents final 2005 data on U.S. deaths, death rates, life expectancy, infant and maternal mortality, and trends by selected characteristics such as age, sex, Hispanic origin, race, marital status, educational attainment, injury at work, state of residence, and cause of death. METHODS: This report presents descriptive tabulations of information reported on death certificates, which are completed by funeral directors, attending physicians, medical examiners, and coroners. The original records are filed in the state registration offices. Statistical information is compiled into a national database through the Vital Statistics Cooperative Program of the Centers for Disease Control and Prevention's National Center for Health Statistics (NCHS). Causes of death are processed in accordance with the International Classification of Diseases, Tenth Revision (ICD-10). RESULTS: In 2005, a total of 2,448,017 deaths were reported in the United States. The age-adjusted death rate was 798.8 deaths per 100,000 standard population, representing a decrease of 0.2 percent from the 2004 rate and a record low historical figure. Life expectancy at birth remained the same as that in 2004-77.8 years. Age-specific death rates decreased for the age group 65-74 years but increased for the age groups 15-24 years, 25-34 years, and 45-54 years. The 15 leading causes of death in 2005 remained the same as in 2004. Heart disease and cancer continued to be the leading and second leading causes of death, together accounting for almost one-half of all deaths. The infant mortality rate in 2005 was 6.87 deaths per 1,000 live births. CONCLUSIONS: Generally, mortality patterns in 2005, such as the age-adjusted death rate declining to a record historical low, were consistent with long-term trends. Life expectancy in 2005 remained the same as that in 2004.

Bereavement

1. Surkan PJ, Rådestad I, Cnattingius S, Steineck G, Dickman PW
Events after stillbirth in relation to maternal depressive symptoms: a brief report
Birth. 2008 Jun;35(2):153-7

Division of Clinical Cancer Epidemiology, Department of Oncology and Pathology, Karolinska Institutet, Stockholm, Sweden

BACKGROUND: Actions taken after a stillbirth can affect long-term psychological morbidity. Our objective was to study how infant bonding and maternal actions after stillbirth are associated with ensuing depressive symptoms. METHODS: Using the population-based Swedish Medical Birth Register, we identified all 380 Swedish-speaking women who gave birth to singleton stillborn infants in Sweden in 1991. Of these, 314 (83%) completed a postal questionnaire 3 years after the stillbirth. Items included actions taken to bond with the baby and demographics. The association between care-related factors and later maternal depressive symptoms was quantified using relative risks estimated using multivariable regression. RESULTS: We observed an almost sevenfold increased risk of depressive symptoms for mothers who reported not being with their babies as long as they wished (adjusted risk ratio [RR] 6.9, 95% CI 2.4-19.8). Compared with women who became pregnant again within 6 months, those with no later pregnancy were at higher risk of depressive symptoms (adjusted RR 2.8, 95% CI 0.9-8.4). In addition, compared with women who experienced a stillbirth in their first pregnancy, stillbirth occurring with an infant who was third in the birth order was related to a twofold risk of elevated depressive symptoms (adjusted RR 2.2, 95% CI 0.8-6.4). Furthermore, stillbirth occurring in a fourth or later pregnancy was associated with an almost sevenfold risk of depressive symptomatology (adjusted RR 6.7, 95% CI 2.2-20.5). No evidence of an association was found between other care-related actions and subsequent maternal depressive symptoms. CONCLUSIONS: Our results suggest that a mother being with the stillborn baby for as long as desired and the birth order of the stillbirth may influence her later depressive symptomatology. Compared with mothers who became pregnant again within 6 months, those who did not have a subsequent pregnancy were at higher risk of depressive symptoms at 3 years' follow-up.

2. McCreight BS
Perinatal loss: a qualitative study in Northern Ireland
Omega (Westport). 2008;57(1):1-19

University of Ulster, School of Sociology and Applied Social Studies, Northern Ireland. bs.mccreight@ulster.ac.uk

This article describes the experiences of women in Northern Ireland who have experienced a miscarriage or stillbirth. Pregnancy loss encompasses several dimensions of loss for women, loss of the future, loss of self-identity, and the loss of anticipated parenthood. The study explored how women emotionally responded to loss and the care they received from medical staff. Burial arrangements for the remains of the baby are also explored. The methodology adopted a narrative approach based upon in-depth interviews with 23 women who attended pregnancy loss self-help groups. The women's narratives highlight their emotional responses to loss, the medicalization of perinatal grief, and burial arrangements. Women felt that their experience was emotionally negative in that they had been subjected to a rationalizing process of medicalization. The primary focus for the women was on the need to recover space for their emotions and seek acceptance and recognition of the validity of their grief. The study demonstrated that the women's response to being marginalized led them to make sense of their experiences and to create spaces of resistance to medicalization. The way in which women placed emotion at the center of their narratives is taken to be a powerful indicator that the support they require from professionals should take account of the meanings they have constructed from their experience of loss.

Miscarriage/Stillbirth/Prenatal Issues

1. Das S, Ankola P, Chiechi M, Sandhu J
Perinatal Cerebral Arterial Infarction Associated with a Placental Chorioangioma
Am J Perinatol. 2008 Jun 2. [Epub ahead of print]

Department of Pediatrics, Metropolitan Hospital Center, New York Medical College, New York, New York

Placental chorioangiomas are benign vascular tumors. Large chorioangiomas cause several obstetric complications, including premature labor, placental abruption, polyhydramnios, fetal hydrops, fetal growth restriction, fetal hepatosplenomegaly, cardiomegaly, congestive heart failure, and fetal death. The neonatal complications are hydrops fetalis, microangiopathic hemolytic anemia, and thrombocytopenia. The cause of perinatal cerebral arterial infarction remains unclear in the majority of cases. Investigators have reported a number of obstetric and neonatal complications in the setting of perinatal stroke, including birth asphyxia, preeclampsia, chorioamnionitis, cardiac anomalies, polycythemia, systemic infection, and genetic thrombophilias. We present a rare case of perinatal cerebral infarction associated with placental chorioangioma.

2. Salihu HM, Alio AP, Wilson RE, Sharma PP, Kirby RS, Alexander GR
Obesity and Extreme Obesity: New Insights Into the Black-White Disparity in Neonatal Mortality
Obstet Gynecol. 2008 Jun;111(6):1410-1416

Departments of Epidemiology and Biostatistics, Obstetrics and Gynecology, Community and Family Health, and Pediatrics, University of South Florida, Tampa, Florida; the Department of Epidemiology, UMDNJ-School of Public Health, New Brunswick, New Jersey; and the Department of Maternal and Child Health, University of Alabama at Birmingham, Birmingham, Alabama.

OBJECTIVE: To estimate whether the preponderance of obesity among black women could explain the black-white disparity in neonatal mortality. METHODS: This is a population-based study using longitudinally collected data among pregnant women from the state of Missouri spanning almost two decades (1978-1997). Obesity is defined in this study as body mass index (BMI) of at least 30 and further categorized into the typically reported three subclasses: class I (BMI 30.0-34.9), class II (BMI 35.0-39.9), and extreme/morbid obesity (BMI at least 40). The main outcome measures were neonatal mortality, early neonatal mortality, and late neonatal mortality. RESULTS: Overall, neonatal mortality and early neonatal mortality but not late neonatal mortality increased with higher obesity subclass, with the greatest risk registered among morbidly obese mothers (hazards ratio for neonatal mortality 1.3; 95% confidence interval [CI] 1.1-1.5; hazards ratio for early neonatal mortality 1.3; 95% CI 1.1-1.5). Among blacks, the risk for neonatal, early, and late neonatal mortality increased significantly with rising BMI (50-100% increments). However, offspring of obese white mothers had no elevated risks for any of the three indices of mortality regardless of maternal obesity subclass. CONCLUSION: Neonates of obese black mothers have an elevated risk of mortality throughout the neonatal period, whereas those of obese white mothers do not. Obesity among black mothers may contribute to the persistent black-white disparity in infant survival in the United States and could provide an avenue for narrowing the black-white gap in infant mortality. LEVEL OF EVIDENCE: II.

3. Tokyol C, Aktepe F, Husniye Dilek F, Yilmazer M
Comparison of Placental PTEN and beta1 Integrin Expression in Early Spontaneous Abortion, Early and Late Normal Pregnancy
Ups J Med Sci. 2008;113(2):235-42

Departments of Pathology, Afyon Kocatepe University School of Medicine, Afyonkarahisar, Turkey

Background: PTEN seems to play an important role in cell cycle, growth, migration, and death. Integrins are cell surface receptors that play a role in the regulation of cell proliferation, differentiation, implantation, and embryogenesis. PTEN inhibits 1 integrin signaling. The objective of this study is to investigate the expression of PTEN and 1 integrin in placental tissues of early spontaneous abortion and first and third trimesters of normal pregnancy.Method: A total of 43 placental tissue samples were evaluated using immunohistochemistry for PTEN and 1 integrin. Group 1 included placental tissues of volunteer termination of normal pregnancy during the first trimester (5-10 wk gestation). Group 2 included placental tissues of normal vaginal delivery at the third trimester of pregnancy (36-40 wk gestation). Group 3 included placental tissues of pregnancy termination because of spontaneous abortion during the first trimester (5-10 wk gestation). Results: PTEN expression of villous trophoblast was decreasing as the pregnancy advanced. PTEN staining of decidual cells was significantly stronger in tissue samples from early spontaneous abortion than in tissue samples from early and late normal pregnancy (p=0.003, p=0.001, respectively). There was no significant difference between 1 integrin expression of villous trophoblast and decidual cells in three groups.Conclusion: Our findings suggest that altered patterns of PTEN expression may be associated with abortion, but it seems that 1 integrin does not contribute to this process as a signaling protein. Further evaluation is needed to highlight this subject.

4. Moreau P, Contu L, Alba F, Lai S, Simoes R, Orrù S, Carcassi C, Roger M, Rabreau M, Carosella ED
HLA-G Gene Polymorphism in Human Placentas: Possible Association of G*0106 Allele with Preeclampsia and Miscarriage
Biol Reprod. 2008 May 28 [Epub ahead of print]

Definite causes for several pregnancy pathologies remain unknown. However, in the light of different recent studies, it is notable that diminished or aberrant HLA-G expression may be associated with certain complication of pregnancy, and may be further link to HLA-G polymorphism. We analysed DNA from 60 normal placentas (controls), 140 placentas from miscarriage, 36 pre-eclamptic placentas, 76 placentas from fetal hypotrophy and 34 placentas with hypoxia, for variations in coding regions (allelic groups G*0101 to G*0107), and the 14 bp deletion/insertion into the 3'UT region. No statistically significant differences were observed in the distribution of allelic group between pathological placentas and controls with the exception of G*0106 allele frequency in pre-eclampsia compared with control placentas (21.2 % and 6.6 % respectively). A greater frequency of this allele also was observed in two subgroups of miscarriage and hypoxia pathologies than in the controls. In addition, the presence of the 14 bp sequence was prominent in pre-eclampsia compared with control (60.8 % versus 35 %) and homozygotes with deletion were not detected in the pathology. The results suggest that G*0106 allele which is coupled with the presence of 14 bp contribute and/or is a relevant marker in some specific pregnancy complications, especially pre-eclampsia.

5. Bartholin L, Melhuish TA, Powers SE, Goddard-Léon S, Treilleux I, Sutherland AE, Wotton D
Maternal Tgif is required for vascularization of the embryonic placenta
Dev Biol. 2008 May 2. [Epub ahead of print]

Department of Biochemistry and Molecular Genetics, University of Virginia, USA; Center for Cell Signaling, University of Virginia, USA

The mammalian placenta is the site of exchange of nutrients and waste between mother and embryo. In humans, placental insufficiency can result in intrauterine growth retardation, perinatal death and spontaneous abortion. We show that in C57BL/6J mice a null mutation in the gene encoding the transcriptional corepressor, Tgif, causes placental defects. The major defects are decreased vascularization of the placenta, due to a decrease in the fetal blood vessels, and decreased expression of the gap junction protein Gjb2 (Cx26). These defects result in severe growth retardation in a proportion of Tgif null embryos in Tgif heterozygous mothers, and an overall growth delay in Tgif null animals. Placental defects are much more severe if the mother also completely lacks Tgif function, and placentas from heterozygous Tgif embryos are defective in a Tgif null mother. Embryo transfer experiments show that even the placenta from a wild type embryo is compromised in the absence of maternal Tgif. These results demonstrate that Tgif functions in the normal development of the placenta, and suggest a role for maternal factors in regulating the morphogenesis of embryonically-derived placental tissues.

6. Fellman J, Eriksson AW
Correlations between live and stillbirth outcomes in twin pairs
Hum Biol. 2008 Feb;80(1):29-40

Folkhälsan Institute of Genetics, Department of Genetic Epidemiology, PO Box 211, Fin-00251 Helsinki, Finland.

A relationship has been proposed to exist between individual outcomes (live or stillbirth) of twins in the same set. Here, we analyze this association between live births and stillbirths among individuals in different twin pairs. When national birth registers are analyzed, individuals in opposite-sex twin sets can be identified and the correlation between individual outcomes estimated. However, full information about the individuals in same-sex twin sets is not, as a rule, available, and consequently, correlation coefficients cannot be estimated, but upper and lower limits of the correlation coefficients can be obtained. The methods introduced here were applied to data from Sweden (1869-1967), the Aland Islands (Finland) (1750-1949), the Kingdom of Saxony (1881-1900), and England and Wales (1940-2003). Comparisons between the correlation coefficients among opposite-sex twins and the lower bound (minimum) of correlation coefficients among same-sex twins indicate that in all populations studied a stronger association exists between twins in same-sex rather than opposite-sex twin sets or pairs. For opposite-sex twin sets no general association between the correlation coefficient and the stillbirth rate was identified.

Prepared by the
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