Placental Findings Contributing to Perinatal Death: A 15-Year Retrospective Review from a Teaching Hospital in Thailand

Introduction: The placenta is infrequently examined in developing countries. This study examined the role of placental pathology in perinatal deaths at Chulalongkorn University Hospital, Bangkok. Methods: Included were singleton intrauterine deaths after gestational week 20 and live-born infants up to 1 week old, over a 15-year period. Placental lesions were classified as: inflammatory-immune, maternal stromal-vascular, fetal stromal-vascular, umbilical cord complications and other. Results: 208 such cases had the placenta available. A placental cause of death was found in 96 (46%), non-placental causes in 28% and the cause of death was unknown in 26%. Of those 96 placentas, 44% were categorized as inflammatory-immune, 30% maternal stromal-vascular, 13% fetal stromal-vascular, 7% umbilical cord complications and 6% other. Conclusions: Placental causes of death were less common than in many Western studies, but inflammatory-immune processes more common. These differences may relate to how cases were accrued, and/or local socioeconomic factors, and warrant further study.

Maternal B Cell-Intrinsic MyD88 Signaling Mediates LPS-Driven Intrauterine Fetal Death

Immunological networks balance tolerance towards paternal alloantigens during pregnancy with normal immune response to pathogens. Subclinical infections can impact this balance and lead to preterm birth or even intrauterine fetal death (IUFD). We recently showed that loss of maternal B cells renders murine fetuses susceptible to IUFD after LPS exposure. Since the signaling pathway involved in this B-cell mediated response remains unclear, we aimed to understand the participation of MyD88 in this response using B-cell-specific MyD88-deficient (BMyD88-/-) mice. B cells isolated from wild-type (WT), BMyD88-/-, CD19-/- and MyD88-/- dams on gestational day (gd) 10 responded differently to LPS concerning cytokine secretion. In vivo LPS challenge on gd 10 provoked IUFD in CD19-/- mothers with functional MyD88, while fetuses from BMyD88-/- and MyD88-/- mice were protected. These outcomes were associated with altered cytokine levels in the maternal serum and changes in CD4+ T-cell responses. Overall, the loss of MyD88 signaling in maternal B cells prevents the activation of cytokine release that leads to IUFD. Thus, while MyD88 signaling in maternal B cells protects the mother from infection, it ultimately kills the fetus. Understanding the cellular mechanisms underlying infection-driven pregnancy complications is the first step to designing powerful therapeutic strategies in the future.

Stillbirth With Group B Streptococcus Disease Worldwide: Systematic Review and Meta-analyses

Background

There are an estimated 2.6 million stillbirths each year, many of which are due to infections, especially in low- and middle-income contexts. This paper, the eighth in a series on the burden of group B streptococcal (GBS) disease, aims to estimate the percentage of stillbirths associated with GBS disease.

Methods

We conducted systematic literature reviews (PubMed/Medline, Embase, Literatura Latino-Americana e do Caribe em Ciências da Saúde, World Health Organization Library Information System, and Scopus) and sought unpublished data from investigator groups. Studies were included if they reported original data on stillbirths (predominantly ≥28 weeks’ gestation or ≥1000 g, with GBS isolated from a sterile site) as a percentage of total stillbirths. We did meta-analyses to derive pooled estimates of the percentage of GBS-associated stillbirths, regionally and worldwide for recent datasets.

Results

We included 14 studies from any period, 5 with recent data (after 2000). There were no data from Asia. We estimated that 1% (95% confidence interval [CI], 0–2%) of all stillbirths in developed countries and 4% (95% CI, 2%–6%) in Africa were associated with GBS.

Conclusions

GBS is likely an important cause of stillbirth, especially in Africa. However, data are limited in terms of geographic spread, with no data from Asia, and cases worldwide are probably underestimated due to incomplete case ascertainment. More data, using standardized, systematic methods, are critical, particularly from low- and middle-income contexts where the highest burden of stillbirths occurs. These data are essential to inform interventions, such as maternal GBS vaccination.

Group B Streptococcus and perinatal mortality

The World Health Organization estimates that every year, one million neonatal deaths occur because of neonatal infection. Furthermore, an equal number of stillbirths are thought to be caused by infections. Here we discuss the role of Streptococcus agalactiae (group B Streptococcus, GBS) in neonatal disease and stillbirth.

The role of Escherichia coli in reproductive health: state of the art

Escherichia coli is a well-known commensal of the normal intestinal microbiome that can also colonize the vaginal microbiome, usually without symptoms. However, E. coli can also be a highly virulent and frequently deadly pathogen. In this review, I will discuss the role E. coli has in reproductive health and disease.

Prevalence and risk factors of chorioamnionitis in Dhaka, Bangladesh

OBJECTIVE

To estimate the association between chorioamnionitis, maternal risk factors and birth outcomes.

STUDY DESIGN

A cross-sectional study of 600 pregnant women was conducted at a maternity center in Dhaka from January to October 2011. Outcomes included histologic, microbiologic and clinical chorioamnionitis. Log-binomial models assessed the association between risk factors and histologic chorioamnionitis (HC).

RESULTS

Of the 552 women with placental specimens, 70 (12.7%) were classified with HC: 46 (65.7%) with and 24 (34.3%) without fetal involvement. HC was associated with non-physician care (relative risk [RR] 2.04, 95% confidence interval [CI] 1.04 to 4.00), home slab or hanging latrine (RR 1.69, 95% CI 1.10 to 2.62), and lack of tetanus toxoid (RR 1.80, 95% CI 1.03 to 3.14). Women with fever (RR 2.30, 95% CI 1.18 to 4.50) or discolored amniotic fluid (RR 1.74, 95% CI 1.08 to 2.81) had a higher risk of HC. Microbiologic and clinical chorioamnionitis were unreliable HC measures.

CONCLUSION

Prevalence of HC is high; many cases are not captured by clinical diagnosis or microbiologic cultures.

An lnterleukin-6 Gene Promoter Polymorphism and Unexplained Late Intrauterine Fetal Death: A Multicenter Study

OBJECTIVE

Interleukin-6 (IL-6)-mediated inflammatory processes have been proposed to be involved in the pathogenesis of pregnancy-associated complications such as late unexplained intrauterine fetal death (IUFD). Therefore we determined whether a common guanine/cytosine polymorphism at position -174 of the promoter of the IL-6 gene (IL6) known to affect in vivo protein activity can serve as candidate gene for this condition.

METHODS

In a multicenter case-control study, we evaluated the IL6 promoter polymorphism by pyrosequencing in 92 women with IUFD. Ninety-four healthy women with at least one uncomplicated full-term pregnancy and no history of IUFD served as the control group.

RESULTS

No significant association was found between the presence of at least one mutant allele of the IL6 promoter polymorphism (P = .2; odds ratio = 1.5 [95% confidence interval, 0.8-2.7]) and the incidence of IUFD. In women with IUFD, the presence of at least one mutant allele of the IL6 promoter polymorphism did not influence timing of fetal death (33.9 [5.1] gestational weeks vs 34.1 [4.9] gestational weeks, P = .8) or birth weight (2055 [1119] g vs 1963 [992] g, P = .7).

CONCLUSION

To our knowledge, we are the first to report on a common polymorphism of the IL6 promoter gene in women with late IUFD. The investigated IL6 promoter polymorphism can not be seen as candidate gene for IUFD in Caucasian women.

Placenta Accreta in a Woman with Escherichia coli Chorioamnionitis with Intact Membranes

Background. Escherichia coli (E. coli) associated intrauterine infections with intact membranes are extremely rare. Case. A 30-year-old multiparous female presented at 26 weeks' gestation with clinical signs of chorioamnionitis but physical examination suggested intact membranes. Her dietary history was concerned with Listeriosis. An amniocentesis was performed. Shortly thereafter, the mother developed septic shock and an urgent Cesarean delivery was performed. The patient required a peripartum hysterectomy for placenta accreta. Amniotic fluid cultures grew E. coli.

Increased risk for group B Streptococcus sepsis in young infants exposed to HIV, Soweto, South Africa, 2004-2008(1)

Vaccination of pregnant women could prevent 2,105 invasive GBS cases and 278 deaths among infants annually.

Although group B Streptococcus (GBS) is a leading cause of severe invasive disease in young infants worldwide, epidemiologic data and knowledge about risk factors for the disease are lacking from low- to middle-income countries. To determine the epidemiology of invasive GBS disease among young infants in a setting with high maternal HIV infection, we conducted hospital-based surveillance during 2004–2008 in Soweto, South Africa. Overall GBS incidence was 2.72 cases/1,000 live births (1.50 and 1.22, respectively, among infants with early-onset disease [EOD] and late-onset [LOD] disease). Risk for EOD and LOD was higher for HIV-exposed than HIV-unexposed infants. GBS serotypes Ia and III accounted for 84.0% of cases, and 16.9% of infected infants died. We estimate that use of trivalent GBS vaccine (serotypes Ia, Ib, and III) could prevent 2,105 invasive GBS cases and 278 deaths annually among infants in South Africa; therefore, vaccination of all pregnant women in this country should be explored.

Maternal group B Streptococcus-related stillbirth: a systematic review

BACKGROUND

Limited epidemiological data on the association between maternal rectovaginal group B Streptococcus (GBS) colonisation and stillbirth makes assessment of antenatal interventions for GBS stillbirth difficult.

OBJECTIVES

To systematically review the existing literature and evaluate the incidence of GBS-related stillbirth by region up to March 2015.

SEARCH STRATEGY

A systematic review of the published literature was completed using PubMed/MEDLINE, EMBASE, LILACS, and Cochrane Library, with Medical Subject Headings (MeSH) and search terms based upon the Centers for Disease Control and Prevention's (CDC) Active Bacterial Core Surveillance (ABCs) GBS-related stillbirth definition and chorioamnionitis.

SELECTION CRITERIA

Studies reporting original data on GBS-related stillbirth occurring ≥20 weeks of gestation, with GBS confirmed by autopsy or by culture from the placenta, amniotic fluid, or other normally sterile site samples from the stillborn.

DATA COLLECTION AND ANALYSIS

Descriptive analyses were performed with the absolute GBS-related stillbirth rates and proportion of stillbirths attributed to GBS calculated per study where possible. Differences in stillbirth definitions did not allow for pooled estimates to be calculated.

MAIN RESULTS

Seventeen studies reported GBS-related stillbirth rates varying from 0.04 to 0.9 per 1000 births, with the proportion of stillbirths associated with GBS ranging from 0 to 12.1%. Most studies reported data from before the year 2000 and from high-income countries.

CONCLUSIONS

The sparsely available epidemiological evidence was not reported consistently, emphasising the importance of standardised stillbirth definitions and diagnostic methods to optimally assess the effectiveness of any future antenatal interventions. Timing of stillbirth, GBS serotype, and global diversity were gaps in the current evidence.

TWEETABLE ABSTRACT

Systematic review finds Group B Streptococcus causes up to 12.1% of stillbirths, but more research is needed.

The Role of Infection and Inflammation in Stillbirths: Parallels with SIDS?

It has been suggested that stillbirths are part of the spectrum of infant deaths that includes sudden infant death syndrome (SIDS). This paper examines the hypothesis that risk factors associated with stillbirths might contribute to dysregulation of inflammatory responses to infections that could trigger the physiological responses leading to fetal loss. These include genetic factors (ethnic group, sex), environmental (infection, cigarette smoke, obesity), and developmental (testosterone levels) factors. Interactions between the genetic, environmental, and developmental risk factors are also considered, e.g., the excess of male stillborn infants in relation to the effects of testosterone levels during development on pro-inflammatory responses. In contrast to SIDS, inflammatory responses of both mother and fetus need to be considered. Approaches for examining the hypothesis are proposed.

Fetal bacterial infections in antepartum stillbirth: a case series

OBJECTIVES

This study aims to assess the frequency of fetal bacterial infections in stillbirth (SB) and to evaluate the best samples for the diagnosis of infection-related SB.

STUDY DESIGN

Consecutive cases of antepartum SB were enrolled. Vaginal and placental swabs, as well as heart blood cultures and surface swabs from the neonate, were collected. Histological examinations were performed by the same examiner. Immunohistochemistry for leukocyte common antigen was performed in the placenta and fetus. Each case was discussed in a multidisciplinary audit.

RESULTS

One hundred and nine cases were enrolled. Fetal blood cultures were positive in 20/95 cases (21%). Significant histological findings in the placenta/cord and in at least one fetal organ were observed in 8 cases of them (4 Group B Streptococcus GBS, 2 Listeria monocytogenes, 1 Coagulase negative Staphylococcus, 1 Pseudomonas aeruginosa). Neither tissue damage nor inflammatory infiltrate was found in the 12 remnant cases. Funisitis while not histological chorioamnionitis was associated with microbiological findings. Positive findings in maternal/placental/fetal swabs occurred in 18-32% of cases with both negative fetal blood cultures and histopathological findings. With the exception of GBS, no other bacteria agent could be detected by any of the swabs.

CONCLUSIONS

Eight cases (8.4%) fulfilled both microbiological and histology criteria allowing the diagnosis of SB-related fetal infection demonstrating that search for infections is essential in SB evaluation. Fetal blood culture, placenta swab for GBS and search for histological funisitis are mandatory actions within the SB work-up in order to guide pathology examination and reach clinical conclusions.

Both acute and chronic placental inflammation are overrepresented in term stillbirths: a case-control study

OBJECTIVE

To elucidate differences in the frequency and severity of acute chorioamnionitis (CAM) and chronic villitis in placentas from stillborns compared with liveborns at term and to evaluate other risk factors and placental findings.

DESIGN

Case-control study.

SETTING

All delivery wards in major Stockholm area. Population or Sample. Placentas from stillborn/case (n = 126) and liveborn/control (n = 273) neonates were prospectively collected between 2002 and 2005.

METHODS

CAM was assessed on a three-grade scale based on the presence and distribution of polymorphonuclear leucocytes in the chorion/amnion. The presence of vasculitis and funisitis was recorded separately. Chronic villitis was diagnosed by the presence of mononuclear cells in the villous stroma. Relevant clinical data were collected from a specially constructed, web-based database. The statistic analyses were performed using multivariable logistic regression.

RESULTS

CAM (especially severe, AOR: 7.39 CI: 3.05-17.95), villous immaturity (AOR: 7.17 CI: 2.66-19.33), villitis (<1 % AOR: 4.31 CI: 1.16-15.98; ≥ 1 %, AOR: 3.87 CI: 1.38-10.83), SGA (AOR: 7.52 CI: 3.06-18.48), and BMI >24.9 (AOR: 2.06 CI: 1.21-3.51) were all connected to an elevated risk of term stillbirth.

CONCLUSIONS

We found that CAM, chronic villitis, villous immaturity, SGA, and maternal overweight, but not vasculitis or funisitis are independently associated with risk for stillbirth at term.

Histological chorioamnionitis is increased at extremes of gestation in stillbirth: a population-based study

Objective. To determine the incidence of histological chorioamnionitis and a fetal response in stillbirths in New South Wales (NSW), and to examine any relationship of fetal response to spontaneous onset of labour and to unexplained antepartum death. Study Design. Population-based cohort study. Setting. New South Wales Australia. Population. All births between 2002 and 2004 with stillbirths reviewed and classified by the state perinatal mortality review committee. Methods. Record linkage of the Midwives Data Collection and the Perinatal Death Database including placental histopathology and standardised cause of death classification. Results. 952 stillbirths were included. The incidence of histopathological chorioamnionitis was 22.6%, with a bimodal distribution. A fetal inflammatory response was present in 10.1% and significantly correlated with spontaneous onset of labour. The absence of a fetal inflammatory response was strongly associated with unexplained antepartum death. Conclusions. The increased incidence of histological chorioamnionitis at extremes of gestation is confirmed in the largest dataset to date using population data. This has important implications for late gestation stillbirth as the percentage of unexplained stillbirths increases near term.

Infection-related stillbirths

Infection is an important cause of stillbirths worldwide: in low-income and middle-income countries, 50% of stillbirths or more are probably caused by infection. By contrast, in high-income countries only 10-25% of stillbirths are caused by infection. Syphilis, where prevalent, causes most infectious stillbirths, and is the infection most amenable to screening and treatment. Ascending bacterial infection is a common cause of stillbirths, but prevention has proven elusive. Many viral infections cause stillbirths but aside from vaccination for common childhood diseases, we do not have a clear prevention strategy. Malaria, because of its high prevalence and extensive placental damage, accounts for large numbers of stillbirths. Intermittent malarial prophylaxis and insecticide-treated bednets should decrease stillbirths. Many infections borne by animals and vectors cause stillbirths, and these types of infections occur frequently in low-income countries. Research that better defines the relation between these infections and stillbirths, and develops strategies to reduce associated adverse outcomes, should play an important part in reduction of stillbirths in low-income countries.

Infection and stillbirth

Infection may cause stillbirth by several mechanisms, including direct infection, placental damage, and severe maternal illness. Various organisms have been associated with stillbirth, including many bacteria, viruses, and protozoa. In developed countries, between 10% and 25% of stillbirths may be caused by an infection, whereas in developing countries, which have much higher stillbirth rates, the contribution of infection is much greater. In developed countries, ascending bacterial infection, both before and after membrane rupture, with organisms such as Escherichia coli, group B streptococci, and Ureaplasma urealyticum is usually the most common infectious cause of stillbirth. However, in areas where syphilis is prevalent, up to half of all stillbirths may be caused by this infection alone. Malaria may be an important cause of stillbirth in women infected for the first time in pregnancy. The two most important viral causes of stillbirth are parvovirus and Coxsackie virus, although a number of other viral infections appear to be causal. Toxoplasma gondii, Listeria monocytogenes, and the organisms that cause leptospirosis, Q fever, and Lyme disease have all been implicated as etiologic for stillbirth. In certain developing countries, the stillbirth rate is high and the infection-related component so great that achieving a substantial reduction in stillbirth should be possible by reducing maternal infections. However, because infection-related stillbirth is uncommon in developed countries, and because those that do occur are caused by a wide variety of organisms, reducing this etiologic component of stillbirth much further will be difficult.

Viruses and other infections in stillbirth: what is the evidence and what should we be doing?

In Australia, as in other developed countries, approximately 40-50% of stillbirths are of unknown aetiology. Emerging evidence suggests stillbirths are often multifactorial. The absence of a known cause leads to uncertainty regarding the risk of recurrence, which can cause extreme anguish for parents that may manifest as guilt, anger or bewilderment. Further, clinical endeavours to prevent recurrences in future pregnancies are impaired by lack of a defined aetiology. Therefore, efforts to provide an aetiological diagnosis of stillbirth impact upon all aspects of care of the mother, and inform many parts of clinical decision making. Despite the magnitude of the problem, that is 7 stillbirths per 1000 births in Australia, diagnostic efforts to discover viral aetiologies are often minimal. Viruses and other difficult to culture organisms have been postulated as the aetiology of a number of obstetric and paediatric conditions of unknown cause, including stillbirth. Reasons forwarded for testing stillbirth cases for infectious agents are non-medical factors, including addressing all parents' need for diagnostic closure, identifying infectious agents as a sporadic cause of stillbirth to reassure parents and clinicians regarding risk for future pregnancies, and to reduce unnecessary testing. It is clear that viral agents including rubella, human cytomegalovirus (CMV), parvovirus B19, herpes simplex virus (HSV), lymphocytic choriomeningitis virus (LCMV), and varicella zoster virus (VZV) may cause intrauterine deaths. Evidence for many other agents is that minimal or asymptomatic infections also occur, so improved markers of adverse outcomes are needed. The role of other viruses and difficult-to-culture organisms in stillbirth is uncertain, and needs more research. However, testing stillborn babies for some viral agents remains a useful adjunct to histopathological and other examinations at autopsy. Modern molecular techniques such as multiplex PCR, allow searches for multiple agents. Now that such testing is available, it is important to assess the clinical usefulness of such testing.

Chorioamnionitis and fetal response in stillbirth

OBJECTIVE

The purpose of this study was to determine the incidence of chorioamnionitis and fetal inflammatory response in a stillborn cohort and the relationship of fetal response to spontaneous labor, unexplained antepartum death, and spontaneous preterm death.

STUDY DESIGN

In a 15-year hospital cohort study, placental histopathologic evidence, labor onset, gestation, and cause of death classification data were analyzed.

RESULTS

Of 459 stillbirths, 428 stillbirths were included. The incidence of chorioamnionitis was 36.9%, with higher rates evident in early and late gestation. A fetal inflammatory response was present in 13.3% and correlated with spontaneous labor and very early spontaneous preterm death. The absence of a fetal response was associated with unexplained antepartum death.

CONCLUSION

The increased incidence of chorioamnionitis at extremes of gestation in stillbirth is novel and has important implications. The impact of a fetal response is gestation dependent and its absence is associated with unexplained antepartum death.

Stillbirth and Bereavement: Guidelines for Stillbirth Investigation

This document has been archived because it contains outdated information. It should not be consulted for clinical use, but for historical research only. Please visit the journal website for the most recent guidelines.

Use of Vaginally Administered Chlorhexidine During Labor to Improve Pregnancy Outcomes

OBJECTIVE

Our objective was to determine the potential for chlorhexidine used as a vaginal and neonatal wash to reduce adverse outcomes of pregnancy, especially in developing countries.

DATA SOURCES

We searched the English literature from January 1950 through October 2005 for all articles related to the use of chlorhexidine.

METHODS OF STUDY SELECTION

Every article on chlorhexidine use in pregnancy and in the newborn period was reviewed in detail. The results of every study in which chlorhexidine was used as a vaginal treatment, with or without a neonatal wash, for all pregnancy outcomes except mother-to-child transmission of human immunodeficiency virus, are summarized in this review.

TABULATION, INTEGRATION AND RESULTS

Chlorhexidine is a highly effective killer of most bacteria, has an excellent safety profile, rarely is associated with bacterial resistance, is easy to administer, and costs a few cents per application. When used as a vaginal or newborn disinfectant, it clearly reduces bacterial load, including transmission of Group B Streptococcus from the mother to the fetus. Nevertheless, in developed countries, chlorhexidine generally has not been shown to significantly reduce life-threatening maternal or neonatal infections. However, 2 large but not randomized studies, one in Malawi and the other in Egypt, suggest that important reductions in maternal and neonatal sepsis and neonatal mortality may be achievable with vaginal or neonatal chlorhexidine treatment.

CONCLUSION

With 4 million neonates and about 700,000 pregnant or recently pregnant women-mostly in developing countries-dying each year, many from infections originating in the vagina, further study of this highly promising treatment is indicated.

Trends in the cause of late fetal death, 1982-2000

BACKGROUND

Progress in reducing late fetal deaths has slowed in recent years, despite changes in intrapartum and antepartum care.

OBJECTIVES

To describe recent trends in cause-specific fetal death rates.

DESIGN

Retrospective cohort study.

SETTING

North of England.

POPULATION/SAMPLE

3,386 late fetal deaths (> or = 28 weeks of gestation and at least 500 g), occuring between 1982 and 2000.

METHODS

Data on deaths were obtained from the Northern Perinatal Mortality Survey. Data on live births were obtained from national birth registration statistics. Rate ratios (RR) and 95% confidence intervals (CI) for fetal deaths in 1991-2000 compared with 1982-1990 were calculated.

MAIN OUTCOME MEASURES

Cause-specific late fetal death rates per 10,000 total births.

RESULTS

Mortality in singletons declined from 51.5 per 10,000 births in 1982-1990 to 42.0 in 1991-2000 (RR 0.82, 95% CI 0.76-0.87). There was a greater decline in multiples, from 197.9 to 128.0 per 10,000 (RR 0.65, 95% CI 0.51-0.83). In singletons, the largest reductions occurred in intrapartum-related deaths, and deaths due to congenital anomalies, antepartum haemorrhage and pre-eclampsia. There was little change in the rate of unexplained antepartum death occurring at term (RR 0.97, 95% CI 0.84-1.11) or preterm (RR 0.94, 95% CI 0.82-1.07), these accounting for about half of all late fetal deaths. Unexplained antepartum deaths declined in multiple births and in singletons of birthweight < 1500 g.

CONCLUSIONS

While late fetal mortality due to many specific causes has declined, unexplained antepartum death rates have remained largely unchanged. Improved identification of deaths due to growth restriction and infection, which may otherwise be classified as unexplained, is important. Further investigation of the underlying aetiologies of genuinely unexplained deaths is needed.

The possible role of intrauterine infections in unexplained second trimester abortions and macerated stillbirths: a study from a single center

OBJECTIVE

To investigate the role of intrauterine infections in unexplained second trimester abortions and stillbirths.

STUDY DESIGN

Histopathologic and microbiologic evidence of intrauterine infection in the placentas, fetal membranes and fetal lung tissues of 18 unexplained second trimester abortions and macerated stillbirth cases as well as the placentas and fetal membranes of 10 healthy term neonates were investigated in a prospective study conducted in Ankara University School of Medicine, Turkey.

RESULTS

Histopathologic chorioamnionitis and placental culture positivity rates in the study and control groups were 64.7 vs 0%. Bacteria were recovered from 90.9% of placentas and 36.4% of fetal lungs of the cases with histopathologic chorioamnionitis. Intrauterine infection was found in 66.7% of the whole study group, in 85.7% of the unexplained second trimester abortions, and in 54.5% of the macerated stillbirths.

CONCLUSION

Intrauterine infection may be an important factor in unexplained stillbirths and second trimester abortions in centers where pregnancy follow-ups lack evaluation for asymptomatic infection.

Maternal and fetal inflammatory responses in unexplained fetal death

OBJECTIVE

The role of intra-amniotic infection in the etiology of fetal death has been proposed. This study was conducted to determine the prevalence of microbial invasion of the amniotic cavity (MIAC) and the frequency of maternal and/or fetal inflammation in patients presenting with a fetal death.

METHODS

A prospective study was conducted in patients with a fetal death. Amniocenteses were performed for clinical indications (karyotype), as well as to assess the microbiological and cytological state of the amniotic cavity. Fluid was cultured for aerobic and anaerobic bacteria and genital mycoplasmas. An amniotic fluid white blood cell count and glucose determinations were also performed. Histological examination of the placenta was conducted to identify a maternal inflammatory response (acute chorioamnionitis) or a fetal inflammatory response (funisitis).

RESULTS

This study included 44 patients with intrauterine fetal death. The median gestational age at diagnosis was 30.1 weeks (range 16.3-40.4 weeks). One patient had documented MIAC (1/44). Acute histological chorioamnionitis was found in 20.9% (9/43), but a fetal inflammatory response was observed in only 2.3% (1/43) of cases. One patient had a positive amniotic fluid culture for Streptococcus agalactiae (group B streptococcus).

CONCLUSION

Histological chorioamnionitis was present in 20.9% of cases, but MIAC could be demonstrated with conventional microbiological techniques in only one case. A fetal inflammatory response was nine times less frequent than a maternal inflammatory response (maternal 20.9% vs. fetal 2.3%, p = 0.008) in cases of fetal death.

Previous preterm and small-for-gestational-age births and the subsequent risk of stillbirth

BACKGROUND

Some causes of stillbirth may also lead to fetuses that are small for gestational age (have a low birth weight with respect to their gestational age) or are delivered preterm (before 37 weeks of gestation). It is not known whether the birth of a previous small-for-gestational-age or preterm infant increases the subsequent risk of stillbirth.

METHODS

We assessed the associations between previous adverse outcomes of pregnancy and the risk of stillbirth in a nationwide Swedish study of 410,021 women who delivered first and second consecutive singleton infants between 1983 and 1997. There were 1842 and 1062 stillbirths during the first and second pregnancies, respectively.

RESULTS

As compared with women whose first infant was born at term (37 weeks of gestation or more) and was not small for gestational age, women whose first infant was born at term or preterm and was small for gestational age had an increased risk of stillbirth during their second pregnancy. The odds ratios for subsequent stillbirth, after adjustment for covariates known to be associated with an increased risk of stillbirth, were 2.1 (95 percent confidence interval, 1.6 to 2.8) among women with a first infant who was born at term and was small for gestational age, 3.4 (95 percent confidence interval, 2.1 to 5.6) among women with a first infant who was moderately (32 to 36 weeks of gestation) preterm and small for gestational age, and 5.0 (95 percent confidence interval, 2.5 to 9.8) among women with a first infant who was very (before 32 weeks of gestation) preterm and was small for gestational age. The odds ratio for subsequent stillbirth among women with a first stillborn infant was 2.5 (95 percent confidence interval, 1.4 to 4.7), as compared with women whose first infant was not stillborn. The rates of stillbirth in second pregnancies ranged from 2.4 per 1000 births among women whose first infant was born at term and was not small for gestational age to 19.0 per 1000 births among women whose first child was very preterm and was small for gestational age.

CONCLUSIONS

Delivery of a previous small-for-gestational-age infant is an important predictor of the subsequent risk of stillbirth, particularly if the infant was delivered preterm.

The infectious origins of stillbirth

OBJECTIVE

Our objective was to determine the relationship between various types of perinatal infections and stillbirths.

STUDY DESIGN

By use of various textbooks on perinatal infections, multiple MEDLINE searches, and the reference list of all appropriate manuscripts, the appropriate English language literature was reviewed to define the relationship between various perinatal infections and stillbirths.

RESULTS

Infection may cause stillbirth by a number of mechanisms, including direct infection, placental damage, and severe maternal illness. A large variety of organisms have been associated with stillbirth, including many bacteria, viruses, and protozoa. In developed countries, between 10% and 25% of stillbirths may be caused by an infection, whereas in developing countries, which often have much higher stillbirth rates, the contribution of infection is much greater. Ascending bacterial infection, both before and after membrane rupture, with organisms such as Escherichia coli, group B streptococci, and Ureaplasma urealyticum is usually the most common infectious cause of stillbirth. However, in areas where syphilis is very prevalent, up to half of all stillbirths may be caused by this infection alone. Malaria may be an important cause of stillbirth in women infected for the first time in pregnancy. The two most important viral causes of stillbirth are parvovirus and Coxsackie virus, although a number of other viral infections appear to be causal. Toxoplasma gondii, leptospirosis, Listeria monocytogenes, and the organisms that cause leptospirosis, Q fever, and Lyme disease have all been implicated as etiologic for stillbirth.

CONCLUSION

Because infection-related stillbirth is relatively rare in developed countries, and those that do occur are caused by a wide variety of organisms, reducing this etiologic component of stillbirth much further will be difficult. However, in certain developing countries, the stillbirth rate is so high and the infection-related component so great that achieving a substantial reduction in stillbirth should be possible simply by reducing maternal infections.