Cause of and factors associated with stillbirth: a systematic review of classification systems

Multidisciplinary Workup for Stillbirth at a Tertiary-Care Hospital in Northeast Mexico: Findings, Challenges and Perspectives

OBJECTIVES

Stillbirth is an important health problem, and in Mexico, only half of the stillbirths have an explainable cause. The aim of this study was to implement a multidisciplinary workup to identify the etiology and potential risk factors for stillbirth at the Hospital Universitario "Dr. José Eleuterio González".

METHODS

This is a prospective, descriptive, observational study that included stillbirths from the Obstetrics Service from October 1st, 2019 to May 25, 2020. Evaluation strategies included a complete maternal medical history, physical examination of the fetus, and a photographic medical record. For every stillbirth either a prenatal ultrasound, a postnatal x-ray, or a fetal autopsy, were needed. Multiplex Ligation Probe Amplification (MLPA) was performed with an umbilical cord sample.

RESULTS

Thirty-three stillbirths were reported; 21 were included in the analysis. Eleven women (52.3%) had known risk factors for stillbirth, mainly elevated body mass index and diabetes. On physical examination, external birth defects were found in 8 fetuses (38%). X-ray was performed in 14 cases (66%), alterations were detected as a probable etiologic cause just in one. All cases underwent MLPA, which were reported negative. Three cases had criteria for autopsy. Findings were inconclusive to determine etiology.

CONCLUSIONS

The best tools for evaluation of stillbirth were the elaboration of clinical history, physical examination, and prenatal ultrasound. Diabetes and obesity were the most frequent risk factors found in our population. These factors are preventable by implementing strategies that lead to better prenatal care.

Identifying causes and associated factors of stillbirths using autopsy of the fetus and placenta

PURPOSE

The study aimed to evaluate the causes of death and associated factors in cases of stillbirth, using post-mortem examination and applying a rigorous, evidence-based holistic approach.

METHODS

Our retrospective observational study included cases of autopsy following stillbirth that occurred at our tertiary medical center during a period of 8 years. Detailed up-to-date criteria that incorporate clinical reports, medical history, prenatal imaging, and histopathological findings were used to evaluate the cause of death and associated factors.

RESULTS

After applying our proposed methodology, 138 cases of stillbirth were classified into eight categories based on the causes of death. A definitive cause of death was observed in 100 (72%) cases, while 38 (28%) cases were considered unexplained. The leading cause of death was placental lesions (n = 39, 28%) with maternal vascular malperfusion (MVM) lesions being the most common (54%). Ascending infection was the second most common cause of fetal death (n = 24, 17%) and was often seen in the setting of preterm labor and cervical insufficiency.

CONCLUSION

The largest category of cause of death was attributed to placental pathology. Using rigorous detailed up-to-date criteria that incorporate pathological and clinical factors may help in objectively classifying the cause of death.

Identifying avoidable causes of perinatal deaths in a district hospital in Lesotho

BACKGROUND

 Certain determinants can be associated with avoidable perinatal deaths, and audits are needed to establish what these determinants are, and what can be done to prevent such deaths.

OBJECTIVES

 The study aimed at identifying and describing determinants associated with avoidable perinatal deaths at a district hospital in Lesotho and strategies to curb their occurrence.

METHOD

 A retrospective descriptive study was conducted using 142 anonymised obstetric records from January 2018 to December 2020. A data collection tool was adopted from the Perinatal Problem Identification Programme. In this tool, avoidable determinants are referred to as 'factors' or 'problems'.

RESULTS

 A concerning number of perinatal deaths were secondary to avoidable patient factors, namely a delay in seeking medical care, inappropriate responses to antepartum haemorrhage, and inadequate responses to poor foetal movements. Medical personnel factors are also worth observing, namely incorrect use of partograph, insufficient notes to comment on avoidable factors and 'other' medical personnel problems. Ranking highest among administrative problems were the unavailability of intensive care unit beds and ventilators and inadequate resuscitation equipment. Administrative problems accounted for more perinatal deaths than the patient-related factors and medical personnel factors.

CONCLUSION

 There is an urgent need for periodic audits, health education for patients, staff competency and the necessary equipment to resuscitate neonates.Contribution: Avoidable determinants associated with perinatal deaths in a district hospital in Lesotho could be identified. This information provides an understanding of what can be done to limit avoidable perinatal deaths.

The application of the ICD-10 for antepartum stillbirth patients in a referral centre of Eastern China: a retrospective study from 2015 to 2022

BACKGROUND

The causes of some stillbirths are unclear, and additional work must be done to investigate the risk factors for stillbirths.

OBJECTIVE

To apply the International Classification of Disease-10 (ICD-10) for antepartum stillbirth at a referral center in eastern China.

METHODS

Antepartum stillbirths were grouped according to the cause of death according to the International Classification of Disease-10 (ICD-10) criteria. The main maternal condition at the time of antepartum stillbirth was assigned to each patient.

RESULTS

Antepartum stillbirths were mostly classified as fetal deaths of unspecified cause, antepartum hypoxia. Although more than half of the mothers were without an identified condition at the time of the antepartum stillbirth, where there was a maternal condition associated with perinatal death, maternal medical and surgical conditions and maternal complications during pregnancy were most common. Of all the stillbirths, 51.2% occurred between 28 and 37 weeks of gestation, the main causes of stillbirth at different gestational ages also differed. Autopsy and chromosomal microarray analysis (CMA) were recommended in all stillbirths, but only 3.6% received autopsy and 10.5% underwent chromosomal microarray analysis.

CONCLUSIONS

The ICD-10 is helpful in classifying the causes of stillbirths, but more than half of the stillbirths in our study were unexplained; therefore, additional work must be done. And the ICD-10 score may need to be improved, such as by classifying stillbirths according to gestational age. Autopsy and CMA could help determine the cause of stillbirth, but the acceptance of these methods is currently low.

Placental Lesions Associated With Stillbirth by Gestational Age, as Related to Cause of Death: Follow-Up Results From the Stillbirth Collaborative Research Network

BACKGROUND

We previously identified placental lesions associated with stillbirths of varying gestational ages (GA) using advanced feature analysis. We further investigated the relationships between placental lesions and cause of death in stillbirths within these GA ranges.

METHODS

Using data from the Stillbirth Collaborative Research Network, we derived a sample of stillbirths who underwent placental examination and Initial Causes of Fetal Death (INCODE) evaluation for determining cause of death. We then compared the rates of causes of death within and among GA ranges (extreme preterm stillbirth [PTSB] [<28 weeks], early PTSB [28-336/7 weeks], late PTSB [34-366/7 weeks], term stillbirth [≥37 weeks]) according to the presence of these lesions.

RESULTS

We evaluated 352 stillbirths. In extreme PTSB, obstetric complications and infections were associated with acute funisitis. In early PTSB, uteroplacental insufficiency was associated with parenchymal infarcts. In term stillbirth (vs early PTSB), increased syncytial knots were associated with umbilical cord causes and infection.

CONCLUSIONS

Placental lesions of high importance in distinguishing stillbirths at different GAs are associated with specific causes of death. This information is important in relating the presence of placental lesions and fetal death and in helping to understand etiologies of stillbirths at different GAs.

Effects of community-based interventions for stillbirths in sub-Saharan Africa: a systematic review and meta-analysis

Background

Sub-Saharan Africa (SSA) alone contributed to 42% of global stillbirths in 2019, and the rate of stillbirth reduction has remained slow. There has been an increased uptake of community-based interventions to combat stillbirth in the region, but the effects of these interventions have been poorly assessed. Our objectives were to examine the effect of community-based interventions on stillbirth in SSA.

Methods

In this systematic review and meta-analysis, we searched eight databases (MEDLINE [OvidSP], Embase [OvidSP], Cochrane Central Register of Controlled Trials, Global Health, Science Citation Index and Social Science Citation index [Web of Science Core Collection], CINAHL [EBSCOhost] and Global Index Medicus) and four grey literature sources from January 1, 2000 to July 7, 2023 for relevant studies from SSA. Community-based interventions targeting stillbirths solely or as part of complex interventions, with or without hospital interventions were included, while hospital-only interventions, microcredit schemes and maternity waiting home interventions were excluded. Study quality was assessed using the Cochrane risk of bias and National Heart, Lung and Blood Institute's tools. The study outcome was odds of stillbirth in intervention versus control communities. Pooled odds ratios (ORs) were estimated using random-effects models, and subgroup analyses were performed by intervention type and strategies. Publication bias was evaluated by funnel plot and Egger's test. This study is registered with PROSPERO, CRD42021296623.

Findings

Of the 4223 records identified, seventeen studies from fifteen SSA countries were eligible for inclusion. One study had four arms (community only, hospital only, community and hospital, and control arms), so information was extracted from each arm. Analysis of 13 of the 17 studies which had community-only intervention showed that the odds of stillbirth did not vary significantly between community-based intervention and control groups (OR 0.96; 95% CI 0.78-1.17, I2 = 57%, p ≤ 0.01, n = 63,884). However, analysis of four (out of five) studies that included both community and health facility components found that in comparison with community only interventions, this combination strategy significantly reduced the odds of stillbirth by 17% (OR 0.83; 95% CI 0.79-0.87, I2 = 11%, p = 0.37, n = 244,868), after excluding a study with high risk of bias. The quality of the 17 studies were graded as poor (n = 2), fair (n = 9) and good (n = 6).

Interpretation

Community-based interventions alone, without strengthening the quality and capacity of health facilities, are unlikely to have a substantial effect on reducing stillbirths in SSA.

Funding

Nuffield Department of Population Health, Balliol College, the Clarendon Fund, Medical Research Council.

Proteomic profile of extracellular vesicles in maternal plasma of women with fetal death

OBJECTIVES

Fetal death is a complication of pregnancy caused by multiple etiologies rather than being the end-result of a single disease process. Many soluble analytes in the maternal circulation, such as hormones and cytokines, have been implicated in its pathophysiology. However, changes in the protein content of extracellular vesicles (EVs), which could provide additional insight into the disease pathways of this obstetrical syndrome, have not been examined. This study aimed to characterize the proteomic profile of EVs in the plasma of pregnant women who experienced fetal death and to evaluate whether such a profile reflected the pathophysiological mechanisms of this obstetrical complication. Moreover, the proteomic results were compared to and integrated with those obtained from the soluble fraction of maternal plasma.

METHODS

This retrospective case-control study included 47 women who experienced fetal death and 94 matched, healthy, pregnant controls. Proteomic analysis of 82 proteins in the EVs and the soluble fractions of maternal plasma samples was conducted by using a bead-based, multiplexed immunoassay platform. Quantile regression analysis and random forest models were implemented to assess differences in the concentration of proteins in the EV and soluble fractions and to evaluate their combined discriminatory power between clinical groups. Hierarchical cluster analysis was applied to identify subgroups of fetal death cases with similar proteomic profiles. A p-value of <.05 was used to infer significance, unless multiple testing was involved, with the false discovery rate controlled at the 10% level (q < 0.1). All statistical analyses were performed by using the R statistical language and environment-and specialized packages.

RESULTS

Nineteen proteins (placental growth factor, macrophage migration inhibitory factor, endoglin, regulated upon activation normal T cell expressed and presumably secreted (RANTES), interleukin (IL)-6, macrophage inflammatory protein 1-alpha, urokinase plasminogen activator surface receptor, tissue factor pathway inhibitor, IL-8, E-Selectin, vascular endothelial growth factor receptor 2, pentraxin 3, IL-16, galectin-1, monocyte chemotactic protein 1, disintegrin and metalloproteinase domain-containing protein 12, insulin-like growth factor-binding protein 1, matrix metalloproteinase-1(MMP1), and CD163) were found to have different plasma concentrations (of an EV or a soluble fraction) in women with fetal death compared to controls. There was a similar pattern of change for the dysregulated proteins in the EV and soluble fractions and a positive correlation between the log₂-fold changes of proteins significant in either the EV or the soluble fraction (ρ = 0.89, p < .001). The combination of EV and soluble fraction proteins resulted in a good discriminatory model (area under the ROC curve, 82%; sensitivity, 57.5% at a 10% false-positive rate). Unsupervised clustering based on the proteins differentially expressed in either the EV or the soluble fraction of patients with fetal death relative to controls revealed three major clusters of patients.

CONCLUSION

Pregnant women with fetal death have different concentrations of 19 proteins in the EV and soluble fractions compared to controls, and the direction of changes in concentration was similar between fractions. The combination of EV and soluble protein concentrations revealed three different clusters of fetal death cases with distinct clinical and placental histopathological characteristics.

Prenatal ambient air pollutants exposure and the risk of stillbirth in Wuhan, central of China

BACKGROUND

The existing studies on the relationships of prenatal ambient air pollutants exposure with stillbirth in the Chinese population are very limited and the results are inconsistent, and the susceptible windows and potential modifiers for air pollutants exposure on stillbirth remain unanswered.

OBJECTIVE

We aimed to determine the relationships between exposure to ambient air pollutants and stillbirth, and explored the susceptible windows and potential modifiers for air pollutants exposure on stillbirth.

METHODS

A population-based cohort was established through the Wuhan Maternal and Child Health Management Information System involving 509,057 mother-infant pairs in Wuhan from January 1, 2011 through September 30, 2017. Personal exposure concentrations of fine particles (PM_2.5), inhalable particles (PM₁₀), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), carbon monoxide (CO), and ozone (O₃) for mothers were estimated based on their residential address during pregnancy using the inverse distance weighted (IDW) method. We used the logistic regression models to determine the associations at different stages of pregnancy with adjustment for confounding factors.

RESULTS

There were 3218 stillbirths and 505,839 live births among the participants. For each 100 μg/m³ of CO and 10 μg/m³ of O₃ increase in the first trimester (conception to 13⁺⁶ weeks), the risk of stillbirth increased by 1.0% (OR = 1.01, 95%CI: 1.00-1.03) and 7.0% (OR = 1.07, 95%CI: 1.05-1.09). In the second trimester (14 weeks-27⁺⁶ weeks), PM_2.5, PM₁₀, CO, and O₃ exposure were closely related to the risk of stillbirth (P＜0.05). In the third trimester (28 weeks to delivery), for each 10 μg/m³ increase in exposure concentrations of PM_2.5, SO₂, and O₃, the risk of stillbirth increased by 3.4%, 5.9%, and 4.0%, respectively. O₃ exposure was positively relevant to the risk of stillbirth (OR = 1.11, 95%CI: 1.08-1.14) in the whole pregnancy. Exposure to NO₂ was not significantly associated with the risk of stillbirth. Stratified analyses also presented a stronger association among mothers with boy infant, living in rural areas, delivering between 2011 and 2013, and those without gestational hypertension and history of stillbirth.

CONCLUSION

This study provides evidence that maternal exposure to PM_2.5, PM₁₀, SO₂, CO, and O₃ were related to the increased risk of stillbirth. Both the second and third trimesters might be vital susceptible windows for stillbirth. Our findings expand the evidence base for the important impacts of air pollution on fetal growth.

A study on the placenta in stillbirth: an evaluation of molecular alterations through next generation sequencing

INTRODUCTION

Placental dysfunction is one of the most common causes of Intrauterine Fetal Demise (IUFD). Due to its characteristics, the placenta may be the target of molecular research aimed to investigate potential causes of IUFD. In the literature, there are no studies on human placentas that have investigated possible associations between somatic mutations and the occurrence of IUFD. The aim of this study was to identify the presence of gene mutations in placental tissues in a series of cases of IUFD and to evaluate potential correlations with placental microscopic findings.

MATERIALS AND METHODS

Thirty-seven samples of formalin-fixed and paraffin-embedded placental tissues were retrospectively selected from pregnancies ending in IUFD between 23rd to 40th week. Six control placentas of physiological pregnancies were included as controls. After sampling, made according to standardized protocol and conventional histopathological examination, placental tissues were subjected to DNA extraction and sequencing by means of Next Generation Sequencing with a 56-gene panel.

RESULTS

The most frequent mutation observed in 32/37 IUFD cases (86.5%) and absent in any of the 6 control placentas was in c-KIT gene, which is implicated in placental tissue differentiation. However, no significant correlation was found between the presence of individual gene mutations and placental histopatological findings.

DISCUSSION

As the present study found an elevated frequency of c-KIT mutation in IUFD, it further supports the hypothesis that c-KIT is involved in abnormal tissue differentiation leading to altered placental vascularization and function.

Evaluating the impact of maternal health care policy on stillbirth and perinatal mortality in Ghana; a mixed method approach using two rounds of Ghana demographic and health survey data sets and qualitative design technique

BACKGROUND

Stillbirth and perinatal mortality issues continue to receive inadequate policy attention in Ghana despite government efforts maternal health care policy intervention over the years. The development has raised concerns as to whether Ghana can achieve the World Health Organization target of 12 per 1000 live births by the year 2030.

PURPOSE

In this study, we compared stillbirth and perinatal mortality between two groups of women who registered and benefitted from Ghana's 'free' maternal health care policy and those who did not. We further explored the contextual factors of utilization of maternal health care under the 'free' policy to find explanation to the quantitative findings.

METHODS

The study adopted a mixed method approach, first using two rounds of Ghana Demographic and Health Survey data sets, 2008 and 2014 as baseline and end line respectively. We constructed outcome variables of stillbirth and perinatal mortality from the under 5 mortality variables (n = 487). We then analyzed for association using multiple logistics regression and checked for sensitivity and over dispersion using Poisson and negative binomial regression models, while adjusting for confounding. We also conducted 23 in-depth interviews and 8 focus group discussions for doctors, midwives and pregnant women and analyzed the contents of the transcripts thematically with verbatim quotes.

RESULTS

Stillbirth rate increased in 2014 by 2 per 1000 live births. On the other hand, perinatal mortality rate declined within the same period by 4 per 1000 live births. Newborns were 1.64 times more likely to be stillborn; aOR: 1.64; 95% [CI: 1.02, 2.65] and 2.04 times more likely to die before their 6th day of life; aOR: 2.04; 95% [CI: 1.28, 3.25] among the 'free' maternal health care policy group, compared to the no 'free' maternal health care policy group, and the differences were statistically significant, p< 0.041; p< 0.003, respectively. Routine medicines such as folic acid and multi-vitamins were intermittently in short supply forcing private purchase by pregnant women to augment their routine requirement. Also, pregnant women in labor took in local concoction as oxytocin, ostensibly to fast track the labor process and inadvertently leading to complications of uterine rapture thus, increasing the risk of stillbirths.

CONCLUSION

Even though perinatal mortality rate declined overall in 2014, the proportion of stillbirth and perinatal death is declining slowly despite the 'free' policy intervention. Shortage of medicine commodities, inadequate monitoring of labor process coupled with pregnant women intake of traditional herbs, perhaps explains the current rate of stillbirth and perinatal death.

The global use of the International Classification of Diseases to Perinatal Mortality (ICD-PM): A systematic review

Background

The World Health Organization launched the International Classification of Diseases for Perinatal Mortality (ICD-PM) in 2016 to uniformly report on the causes of perinatal deaths. In this systematic review, we aim to describe the global use of the ICD-PM by reporting causes of perinatal mortality and summarizing challenges and suggested amendments.

Methods

We systematically searched MEDLINE, Embase, Global Health, and CINAHL databases using key terms related to perinatal mortality and the classification for causes of death. We included studies that applied the ICD-PM and were published between January 2016 and June 2021. The ICD-PM data were extracted and a qualitative analysis was performed to summarize the challenges of the ICD-PM. We applied the PRISMA guidelines, registered our protocol at PROSPERO [CRD42020203466], and used the Appraisal tool for Cross-Sectional Studies (AXIS) as a framework to evaluate the quality of evidence.

Results

The search retrieved 6599 reports. Of these, we included 15 studies that applied the ICD-PM to 44 900 perinatal deaths. Most causes varied widely; for example, "antepartum hypoxia" was the cause of stillbirths in 0% to 46% (median = 12%, n = 95) in low-income settings, 0% to 62% (median = 6%, n = 1159) in middle-income settings and 0% to 55% (median = 5%, n = 249) in high-income settings. Five studies reported challenges and suggested amendments to the ICD-PM. The most frequently reported challenges included the high proportion of antepartum deaths of unspecified cause (five studies), the inability to determine the cause of death when the timing of death is unknown (three studies), and the challenge of assigning one cause in case of multiple contributing conditions (three studies).

Conclusions

The ICD-PM is increasingly being used across the globe and gives health care providers insight into the causes of perinatal death in different settings. However, there is wide variation in reported causes of perinatal death across comparable settings, which suggests that the ICD-PM is applied inconsistently. We summarized the suggested amendments and made additional recommendations to improve the use of the ICD-PM and help strengthen its consistency.

Registration

PROSPERO [CRD42020203466].

A retrospective autopsy study of 42 cases of stillbirth in Avicenna Research Institute

BACKGROUND

According to the World Health Organization about 2.6 million deaths were reported worldwide in 2015. More than 98% of stillbirths occur in developing countries. At present, the causes of many cases of stillbirth are unknown due to the lack of necessary data and autopsies in Iran. The aim of this study was to investigate the most plausible cause of stillbirth by evaluating clinical records and autopsies.

METHODS

A cross-sectional study of 42 stillbirth autopsies in Avicenna Research Institute from 2012 to 2019, was conducted. Data were extracted from a checklist prepared by the project researchers. The checklist contains maternal demographic information, medical history and maternal illness, pregnancy risk factors, placenta and stillbirth information. Collected data were reviewed and classified according to the ReCoDe (Relevant Condition at Death) system.

RESULTS

In the present study, based on ReCoDe classification, related causes of 95.2% of stillbirths were identified and 4.8% were in the unclassified group. The most common causes were: Fetal causes (64.3%), umbilical cord (14.3%), placenta (7.1%), amniotic fluid (4.8%), maternal medical conditions (2.4%). The causes of about 70% of stillbirth in Iran are unexplained, but in this study, using autopsy results and ReCoDe classification, only 4.8% of stillbirth causes remained unexplained.

CONCLUSIONS

In our study, unknown cases were rare after autopsy. But considering the limitations and costs of autopsy, we need to design the guideline to specify cases who need an autopsy. Fetal autopsy, placental examination and clinical information could reduce the proportion of stillbirths that remain unexplained.

Still Birth classification: Application of Relevant Condition at Death (ReCoDe) classification system in a tertiary care hospital of Pakistan

OBJECTIVES

To determine the cause of stillbirth after application of relevant condition at death (ReCoDe) classification system.

METHODS

This was a retrospective cross sectional study of 207 women diagnosed with stillbirth after 24 completed weeks of pregnancy at the Aga Khan University Hospital (AKUH), Karachi between 1st January 2015 and 31st December 2019. The primary objective was to find the cause of stillbirth according to the new classification of relevant condition at death (ReCoDe).

RESULTS

There were a total of 32413 live births and 207 stillbirths during the study period thus stillbirth rate of 6 per 1000 live births. In this study, 80% of women were in the age group of 20-35 years, 16% had advanced maternal age while 3.8% of women accounted for less than 20 years. Among the maternal factors; 54.5% cases were booked and the remaining were were un-booked cases. Pre-eclampsia was the most common associated maternal condition (14.9%).Fetal cause accounted for 34.7% of stillbirths and the fetal growth restriction (FGR) was the most common; 23.6%. After application of ReCoDe classification, in 81% of stillbirth cases associated condition were found and only 18.8% of cases were categorized unexplained.

CONCLUSION

Application of ReCoDe classification is easy to understand and applicable, especially in low resource settings with associated causes identified in vast majority of cases.

Seroprevalence and risk factors of Toxoplasma gondii infection in women with recurrent fetal loss from the province of Khyber Pakhtunkhwa, Pakistan

BACKGROUND

In women with a bad obstetric history (BOH), infection is an established cause of recurrent fetal loss. A common infecting agent is the protozoan parasite Toxoplasma gondii (T. gondii). The aim of this study was to measure the prevalence of toxoplasmosis in women with recurrent fetal loss from the Khyber Pakhtunkhwa province of Pakistan.

METHODS

The study included 360 females aged 16-40 years, of which 180 had a bad obstetric history (study group) and the other 180 had no such history (control group). Blood serum samples were tested for toxoplasma IgM antibodies by Enzyme Linked Immunosorbent Assay and for toxoplasma IgG antibodies using an Immunochromatographic technique.

RESULTS

The overall seroprevalence of toxoplasma infection in study group females was 40.6% and in control group females it was 7.2%. Specifically, IgM prevalence was 12.8% in the study group and 1.1% in the control group. IgG prevalence was 23.9% in the study group and 6.1% in the control group. IgM and IgG combined prevalence was 3.9% in the study group cases. There is a statistically significant association between BOH and seropositivity for T. gondii (p < 0.0001, Chi square test). Various risk factors associated with T. gondii seroprevalence in study and control groups were analyzed.

CONCLUSION

The seroprevalence of toxoplasmosis was significantly higher in women with a bad obstetric history compared to those with no such history. Associated risk factors had no significant effects on the results.

Risk factors for antepartum death in term pregnancies

OBJECTIVE

To identify risk factors for antepartum fetal death (APD) in term pregnancies while considering maternal, pregnancy and fetal characteristics.

MATERIALS AND METHODS

Our study took place between the years 1988-2013. A total of 272,527 singleton births at term were recorded during this time period, including 524 cases of APD (0.2%). Cases of known chromosomal or other fetal abnormalities and cases with poor prenatal care were excluded. In order to identify independent risk factors contributing to antepartum fetal death in term we conducted a multivariate analysis using logistic regression.

RESULTS

The main risk factors found to be significantly associated with APD in term were suspected intrauterine growth restriction (OR = 2.70, p < .001), diabetes (OR = 1.37, p = .05), hypertensive disorders (OR = 1.59, p = .01), advanced maternal age (OR = 1.03, p < .001) and grand-multiparity (OR = 1.79, p < .001). Advanced gestational age was not significantly associated with APD (38.95 vs. 39.44, p < .001).

CONCLUSIONS

Most of the risk factors for antepartum fetal death in term pregnancies found in this study coincide with known risk factors for APD as described in previous studies. We believe that in the presence of these risk factors, closer surveillance and careful medical management of the pregnancy are required, in order to reduce the incidence of APD, including induction of labor at advanced gestational age.

Diagnostic Utility of Pathological Investigations in Late Gestation Stillbirth: A Cohort Study

OBJECTIVE

Near term unexpected stillbirth is a common, complex diagnostic challenge. We review a large cohort of near term to term gestation unexpected fetal deaths to document the common patterns of pathology and evaluate the utility of various standard autopsy procedures.

METHODS

A total of 123 perinatal autopsies consisting of 94 intrauterine fetal deaths (IUFDs) and 29 intrapartum deaths (IPDs) were reviewed. Deaths were classified according to the laboratory investigations establishing cause of death.

RESULTS

Cause of death was attributable to placental pathology without autopsy in 55.3% of IUFD and 17% of IPD. Correlative findings at autopsy increased the ability to establish cause of death in 86.2% of IUFD and 62% of IPD. Histology was largely corroborative, with the brain, lungs, and heart demonstrating significant changes in 46%, 34.5%, and 13.8%, respectively. Microbiology was corroborative but demonstrated single organism growth in 6 of 29 cases of fatal acute chorioamnionitis. Newborn metabolic screening revealed only elevated thyroid-stimulating hormone levels in 3 cases, of questionable relevance. Aneuploidy was established by screening molecular studies in 5 IUFDs, all of which had external or visceral dysmorphism. Karyotype was established in 69 cases and was not contributory in any of the IPD: 3 IUFDs had changes of unknown significance. Cause of death was not established at autopsy in 9% of IUFD and 10% of IPD.

DISCUSSION

This is the largest uniformly investigated cohort of late gestation unexpected fetal deaths studied. We confirm the importance of both placental and fetal autopsy in establishing cause of death. Autopsy histology, microbiology, and cytogenetics provide important but largely corroborative data.

Trends and risk factors associated with stillbirths: A case study of the Navrongo War Memorial Hospital in Northern Ghana

BACKGROUND

Maternal and Child health remains at the core of global health priorities transcending the Millennium Development Goals into the current era of Sustainable Development Goals. Most low and middle-income countries including Ghana are yet to achieve the required levels of reduction in child and maternal mortality. This paper analysed the trends and the associated risk factors of stillbirths in a district hospital located in an impoverished and remote region of Ghana.

METHODS

Retrospective hospital maternal records on all deliveries conducted in the Navrongo War Memorial hospital from 2003-2013 were retrieved and analysed. Descriptive and inferential statistics were used to summarise trends in stillbirths while the generalized linear estimation logistic regression is used to determine socio-demographic, maternal and neonatal factors associated with stillbirths.

RESULTS

A total of 16,670 deliveries were analysed over the study period. Stillbirth rate was 3.4% of all births. There was an overall decline in stillbirth rate over the study period as stillbirths declined from 4.2% in 2003 to 2.1% in 2013. Female neonates were less likely to be stillborn (Adjusted Odds ratio = 0.62 and 95%CI [0.46, 0.84]; p = 0.002) compared to male neonates; neonates with low birth weight (4.02 [2.92, 5.53]) and extreme low birth weight (18.9 [10.9, 32.4]) were at a higher risk of still birth (p<0.001). Mothers who had undergone Female Genital Mutilation had 47% (1.47 [1.04, 2.09]) increase odds of having a stillbirth compared to non FGM mothers (p = 0.031). Mothers giving birth for the first time also had a 40% increase odds of having a stillbirth compared to those who had more than one previous births (p = 0.037).

CONCLUSION

Despite the modest reduction in stillbirth rates over the study period, it is evident from the results that stillbirth rate is still relatively high. Primiparous women and preterm deliveries leading to low birth weight are identified factors that result in increased stillbirths. Efforts aimed at impacting on stillbirths should include the elimination of outmoded cultural practices such as FGM.

Sexually Transmitted Infections in Pregnancy and Reproductive Health: Proceedings of the STAR Sexually Transmitted Infection Clinical Trial Group Programmatic Meeting

The goal of the STAR Sexually Transmitted Infection Clinical Trial Group (STI CTG) Programmatic meeting on Sexually Transmitted Infections (STIs) in Pregnancy and Reproductive Health in April 2018 was to review the latest research and develop recommendations to improve prevention and management of STIs during pregnancy. Experts from academia, government, nonprofit, and industry discussed the burden of STIs during pregnancy; the impact of STIs on adverse pregnancy and birth outcomes; interventions that work to reduce STIs in pregnancy, and the evidence, policy, and technology needed to improve STI care during pregnancy. Key points of the meeting are as follows: (i) alternative treatments and therapies for use during pregnancy are needed; (ii) further research into the relationship between the vaginal microbiome and STIs during pregnancy should be supported; (iii) more research to determine whether STI tests function equally well in pregnant as nonpregnant women is needed; (iv) development of new lower cost, rapid point-of-care testing assays could allow for expanded STI screening globally; (v) policies should be implemented that create standard screening and treatment practices globally; (vi) federal funding should be increased for STI testing and treatment initiatives supported by the Centers for Disease Control and Prevention (CDC), the Centers of Excellence in STI Treatment, public STD clinics, and the President's Emergency Plan for AIDS Relief (PEPFAR).

Understanding cause of stillbirth: a prospective observational multi-country study from sub-Saharan Africa

Background

Every year, an estimated 2.6 million stillbirths occur worldwide, with up to 98% occurring in low- and middle-income countries (LMIC). There is a paucity of primary data on cause of stillbirth from LMIC, and particularly from sub-Saharan Africa to inform effective interventions. This study aimed to identify the cause of stillbirths in low- and middle-income settings and compare methods of assessment.

Methods

This was a prospective, observational study in 12 hospitals in Kenya, Malawi, Sierra Leone and Zimbabwe. Stillbirths (28 weeks or more) were reviewed to assign the cause of death by healthcare providers, an expert panel and by using computer-based algorithms. Agreement between the three methods was compared using Kappa (κ) analysis. Cause of stillbirth and level of agreement between the methods used to assign cause of death.

Results

One thousand five hundred sixty-three stillbirths were studied. The stillbirth rate (per 1000 births) was 20.3 in Malawi, 34.7 in Zimbabwe, 38.8 in Kenya and 118.1 in Sierra Leone. Half (50.7%) of all stillbirths occurred during the intrapartum period.

Cause of death (range) overall varied by method of assessment and included: asphyxia (18.5–37.4%), placental disorders (8.4–15.1%), maternal hypertensive disorders (5.1–13.6%), infections (4.3–9.0%), cord problems (3.3–6.5%), and ruptured uterus due to obstructed labour (2.6–6.1%). Cause of stillbirth was unknown in 17.9–26.0% of cases.

Moderate agreement was observed for cause of stillbirth as assigned by the expert panel and by hospital-based healthcare providers who conducted perinatal death review (κ = 0.69; p < 0.0005). There was only minimal agreement between expert panel review or healthcare provider review and computer-based algorithms (κ = 0.34; 0.31 respectively p < 0.0005).

Conclusions

For the majority of stillbirths, an underlying likely cause of death could be determined despite limited diagnostic capacity. In these settings, more diagnostic information is, however, needed to establish a more specific cause of death for the majority of stillbirths. Existing computer-based algorithms used to assign cause of death require revision.

Application of the ICD-PM classification system to stillbirth in four sub-Saharan African countries

Objective

To identify the causes and categories of stillbirth using the Application of ICD-10 to Deaths during the Perinatal Period (ICD-PM).

Methods

Prospective, observational study in 12 hospitals across Kenya, Malawi, Sierra Leone and Zimbabwe. Healthcare providers (HCPs) assigned cause of stillbirth following perinatal death audit. Cause of death was classified using the ICD-PM classification system.

Findings

1267 stillbirths met the inclusion criteria. The stillbirth rate (per 1000 births) was 20.3 in Malawi (95% CI: 15.0–42.8), 34.7 in Zimbabwe (95% CI: 31.8–39.2), 38.8 in Kenya (95% CI: 33.9–43.3) and 118.1 in Sierra Leone (95% CI: 115.0–121.2). Of the included cases, 532 (42.0%) were antepartum deaths, 643 (50.7%) were intrapartum deaths and 92 cases (7.3%) could not be categorised by time of death. Overall, only 16% of stillbirths could be classified by fetal cause of death. Infection (A2 category) was the most commonly identified cause for antepartum stillbirths (8.6%). Acute intrapartum events (I3) accounted for the largest proportion of intrapartum deaths (31.3%). In contrast, for 76% of stillbirths, an associated maternal condition could be identified. The M1 category (complications of placenta, cord and membranes) was the most common category assigned for antepartum deaths (31.1%), while complications of labour and delivery (M3) accounted for the highest proportion of intrapartum deaths (38.4%). Overall, the proportion of cases for which no fetal or maternal cause could be identified was 32.6% for antepartum deaths, 8.1% for intrapartum deaths and 17.4% for cases with unknown time of death.

Conclusion

Clinical care and documentation of this care require strengthening. Diagnostic protocols and guidelines should be introduced more widely to obtain better data on cause of death, especially antepartum stillbirths. Revision of ICD-PM should consider an additional category to help accommodate stillbirths with unknown time of death.

Health care professionals' knowledge and awareness of the ICD-10 coding system for assigning the cause of perinatal deaths in Jordanian hospitals

Objectives

There is a lack of studying vital registration and disease classification systems in low- and middle-income countries. This study aimed to assess health care professionals’ (HCPs’) level of awareness, knowledge, use, and perceived barriers of the International Classification of Diseases, 10th version (ICD-10) as well as their perceptions of the electronic neonatal death registration system.

Participants and methods

A mixed method approach including descriptive cross-sectional quantitative and focus groups with HCPs (physicians, nurses, and midwives) was used to collect data from four major selected hospitals in Jordan. A total of 16 focus groups were conducted. Also, a survey, which included three case studies about the ability of nurses and physicians to identify cause of death, was completed using structured face-to-face interviews.

Results

Overall, there was congruency between both the quantitative results and the qualitative findings. The majority of nurses and physicians in the four hospitals were not familiar with the ICD-10 coding system and hence reported minimal use of the coding system. Additionally, the majority of HCPs were not aware whether or not their departments used the ICD-10 to record perinatal mortality. These HCPs identified that lack of knowledge, time, staff and support, and an effective and comprehensive electronic system that allows physicians to accurately choose the exact cause of death were their main barriers to the use of the ICD-10 coding system.

Conclusion

Our findings emphasize the importance of developing an effective and comprehensive electronic system which allows HCPs to accurately report and register all perinatal deaths. This system needs to account for the direct and indirect causes of death and for contributing factors such as maternal conditions at the time of perinatal death. Training HCPs on how to use the system is vital for the success and accuracy of the data registration process.

Placenta and Umbilical Cord Cause in Antepartum Deaths

Stillbirth is a sudden and painful event for parents and obstetrical specialists as well. It is, therefore, of greatest importance to be able to give answers for the cause in order to plan a subsequent pregnancy. The aim of this retrospective study is to estimate the placental and umbilical cord cause of intrauterine death in relation to different gestational ages. The study took place on the Medical Birth Registry of Aretaieio Hospital, National and Kapodistrian University, Athens, Greece. We include a total of 19,283 pregnancies from 1998 to 2012. In this study period, 431 embryonic deaths occurred. The clinical history was documented on admission at delivery. Conditions thought to be associated with the intrauterine fetal death were recorded. Gestational age was calculated from the last menstrual period as well as with the three-trimester system. The autopsy, placenta and umbilical cord examination were performed by the same laboratory of pathology in Aretaieio University Hospital. We found that the majority of stillbirths occurred in the second trimester. We examined placenta and umbilical cord in all cases. The most frequent histologic abnormalities were those indicated placental vascular insufficiency. As far as the umbilical cord is concerned we found that the inflammatory disorder was the most common in antepartum deaths. A single umbilical artery was significantly related to gestational diabetes and congenital embryonic anomalies. Finally, our results showed steady declines in antepartum deaths during 1998-2012. As a result, we reached the conclusion that in order to reduce the fetal death rate, we have to insist on the autopsy of the placenta and umbilical cord in order to gain the appropriate information in counseling the parents.

Perinatal death beyond 41 weeks pregnancy: an evaluation of causes and substandard care factors as identified in perinatal audit in the Netherlands

BACKGROUND

Late- and postterm pregnancy are associated with adverse perinatal outcomes, like perinatal death. We evaluated causes of death and substandard care factors (SSFs) in term and postterm perinatal death.

METHODS

We used data from the Perinatal Audit Registry of the Netherlands (PARS). Women with a term perinatal death registered in PARS were stratified by gestational age into early-/full-term (37.0-40.6) and late-/postterm (≥41.0 weeks) death. Cause of death and SSFs ≥41 weeks were scored and classified by the local perinatal audit teams.

RESULTS

During 2010-2012, 947/479,097 (0.21%) term deaths occurred, from which 707 cases (75%) were registered and could be used for analyses. Five hundred ninety-eight early-/full-term and 109 late-/postterm audited deaths were registered in the PARS database. Of all audited cases of perinatal death in the PARS database, 55.2% in the early-/fullterm group occurred antepartum compared to 42.2% in the late-/postterm group, while intrapartum death occurred in 7.2% in the early-/full-term group compared to 19.3% in the late-/postterm group in the audited cases from the PARS database. According to the local perinatal audit, the most relevant causes of perinatal death ≥41 weeks were antepartum asphyxia (7.3%), intrapartum asphyxia (9.2%), neonatal asphyxia (10.1%) and placental insufficiency (10.1%). In the group with perinatal death ≥41 weeks there was ≥1SSF identified in 68.8%. The most frequent SSFs concerned inadequate cardiotocography (CTG) evaluation and/or classification (10.1%), incomplete registration or documentation in medical files (4.6%) or inadequate action on decreased foetal movements (4.6%).

CONCLUSIONS

In the Netherlands Perinatal Audit Registry, stillbirth occurred relatively less often antepartum and more often intrapartum in pregnancies ≥41 weeks compared to pregnancies at 37.0-40.6 weeks in the audited cases from the PARS database. Foetal, intrapartum and neonatal asphyxia were identified more frequently as cause of death in pregnancies ≥41 weeks. The most identified SSFs related to death in pregnancies ≥41 weeks concerned inadequate CTG monitoring (evaluation, classification, registration or documentation) and inadequate action on decreased foetal movements.

Persistent inaccuracies in completion of medical certificates of stillbirth: A cross-sectional study

BACKGROUND

The UK Medical Certificate of Stillbirth (MCS) records information relevant to the cause of stillbirth of infants ≥24 weeks' gestation. A cross-sectional audit demonstrated widespread inaccuracies in MCS completion in 2009 in North West England. A repeat study was conducted to assess whether practice had improved following introduction of a regional care pathway.

METHODS

266 MCS issued in 14 North West England obstetric units during 2015 were studied retrospectively. Cause of death was assigned following review of information available at the time of MCS completion. This was compared to that documented on the MCS, and to data from 2009.

RESULTS

Twenty-three certificates were excluded (20 inadequate data, 3 late miscarriages). 118/243 (49%) MCS contained major errors. Agreement between the MCS and adjudicated cause of stillbirth was fair (Kappa 0.31; 95% CI 0.24, 0.38) and unchanged from 2009 (0.29). In 2015, excluding 34 terminations of pregnancy, the proportion of MCSs documenting "unexplained" stillbirths (113/211; 54%) was reduced compared to 2009 (158/213; 74%); causality could be assigned after case note review in 78% cases. Recognition of fetal growth restriction (FGR) as a cause of stillbirth improved (2015: 30/211; 14% vs 2009: 1/213; 0.5%), although 71% cases were missed. 47% MCSs following termination of pregnancy documented an iatrogenic primary cause of death.

CONCLUSIONS

Completion of MCSs remains inaccurate, particularly in recognition of FGR as a cause of stillbirth. Detailed case note review before issuing the MCS could dramatically improve the usefulness of included information; evaluation of practitioner education programmes/internal feedback systems are recommended.

Criteria for assigning cause of death for stillbirths and neonatal deaths in research studies in low-middle income countries

Accurate knowledge regarding cause of death (COD) for stillbirths and neonatal deaths is crucial, especially in low-income countries, in order for public health and medical officials to choose appropriate interventions likely to reduce these deaths. To date, many of the COD studies in these areas have relied only on obstetric or neonatal clinical information and the determination of COD is likely to be inaccurate. Information related to infectious COD is especially lacking. Thus, without more sophisticated testing, data as currently collected only provide a very weak approximation of the COD and may well lead to adoption of interventions of limited usefulness. In this commentary, we propose recommendations regarding the type of data needed to determine with reasonable accuracy the COD for stillbirths and neonatal deaths in low-resource settings. Using these data, and a method to determine the degree of certainty, we then propose definitions for the most common COD. Our goal is to reduce subjectivity and provide more specificity for the tests used in existing classification systems so that the methodology of COD determination is transparent and able to be replicated over time and from location to location.

Making stillbirths visible: a systematic review of globally reported causes of stillbirth

BACKGROUND

Stillbirth is a global health problem. The World Health Organization (WHO) application of the International Classification of Diseases for perinatal mortality (ICD-PM) aims to improve data on stillbirth to enable prevention.

OBJECTIVES

To identify globally reported causes of stillbirth, classification systems, and alignment with the ICD-PM.

SEARCH STRATEGY

We searched CINAHL, EMBASE, Medline, Global Health, and Pubmed from 2009 to 2016.

SELECTION CRITERIA

Reports of stillbirth causes in unselective cohorts.

DATA COLLECTION AND ANALYSIS

Pooled estimates of causes were derived for country representative reports. Systems and causes were assessed for alignment with the ICD-PM. Data are presented by income setting (low, middle, and high income countries; LIC, MIC, HIC).

MAIN RESULTS

Eighty-five reports from 50 countries (489 089 stillbirths) were included. The most frequent categories were Unexplained, Antepartum haemorrhage, and Other (all settings); Infection and Hypoxic peripartum (LIC), and Placental (MIC, HIC). Overall report quality was low. Only one classification system fully aligned with ICD-PM. All stillbirth causes mapped to ICD-PM. In a subset from HIC, mapping obscured major causes.

CONCLUSIONS

There is a paucity of quality information on causes of stillbirth globally. Improving investigation of stillbirths and standardisation of audit and classification is urgently needed and should be achievable in all well-resourced settings. Implementation of the WHO Perinatal Mortality Audit and Review guide is needed, particularly across high burden settings.

FUNDING

HR, SH, SHL, and AW were supported by an NHMRC-CRE grant (APP1116640). VF was funded by an NHMRC-CDF (APP1123611).

TWEETABLE ABSTRACT

Urgent need to improve data on causes of stillbirths across all settings to meet global targets.

PLAIN LANGUAGE SUMMARY

Background and methods Nearly three million babies are stillborn every year. These deaths have deep and long-lasting effects on parents, healthcare providers, and the society. One of the major challenges to preventing stillbirths is the lack of information about why they happen. In this study, we collected reports on the causes of stillbirth from high-, middle-, and low-income countries to: (1) Understand the causes of stillbirth, and (2) Understand how to improve reporting of stillbirths. Findings We found 85 reports from 50 different countries. The information available from the reports was inconsistent and often of poor quality, so it was hard to get a clear picture about what are the causes of stillbirth across the world. Many different definitions of stillbirth were used. There was also wide variation in what investigations of the mother and baby were undertaken to identify the cause of stillbirth. Stillbirths in all income settings (low-, middle-, and high-income countries) were most frequently reported as Unexplained, Other, and Haemorrhage (bleeding). Unexplained and Other are not helpful in understanding why a baby was stillborn. In low-income countries, stillbirths were often attributed to Infection and Complications during labour and birth. In middle- and high-income countries, stillbirths were often reported as Placental complications. Limitations We may have missed some reports as searches were carried out in English only. The available reports were of poor quality. Implications Many countries, particularly those where the majority of stillbirths occur, do not report any information about these deaths. Where there are reports, the quality is often poor. It is important to improve the investigation and reporting of stillbirth using a standardised system so that policy makers and healthcare workers can develop effective stillbirth prevention programs. All stillbirths should be investigated and reported in line with the World Health Organization standards.

Risk of stillbirth, preterm delivery, and fetal growth restriction following exposure in a previous birth: systematic review and meta-analysis

BACKGROUND

Little is known about the risk of non-recurrent adverse birth outcomes.

OBJECTIVES

To evaluate the risk of stillbirth, preterm birth (PTB), and small for gestational age (SGA) as a proxy for fetal growth restriction (FGR) following exposure to one or more of these factors in a previous birth.

SEARCH STRATEGY

We searched MEDLINE, EMBASE, Maternity and Infant Care, and Global Health from inception to 30 November 2016.

SELECTION CRITERIA

Studies were included if they investigated the association between stillbirth, PTB, or SGA (as a proxy for FGR) in two subsequent births.

DATA COLLECTION AND ANALYSIS

Meta-analysis and pooled association presented as odds ratios (ORs) and adjusted odds ratios (aORs).

MAIN RESULTS

Of the 3399 studies identified, 17 met the inclusion criteria. A PTB or SGA (as a proxy for FGR) infant increased the risk of subsequent stillbirth ((pooled OR 1.70; 95% confidence interval, 95% CI, 1.34-2.16) and (pooled OR 1.98; 95% CI 1.70-2.31), respectively). A combination of exposures, such as a preterm SGA (as a proxy for FGR) birth, doubled the risk of subsequent stillbirth (pooled OR 4.47; 95% CI 2.58-7.76). The risk of stillbirth also varied with prematurity, increasing three-fold following PTB <34 weeks of gestation (pooled OR 2.98; 95% CI 2.05-4.34) and six-fold following preterm SGA (as a proxy for FGR) <34 weeks of gestation (pooled OR 6.00; 95% CI 3.43-10.49). A previous stillbirth increased the risk of PTB (pooled OR 2.82; 95% CI 2.31-3.45), and subsequent SGA (as a proxy for FGR) (pooled OR 1.39; 95% CI 1.10-1.76).

CONCLUSION

The risk of stillbirth, PTB, or SGA (as a proxy for FGR) was moderately elevated in women who previously experienced a single exposure, but increased between two- and three-fold when two prior adverse outcomes were combined. Clinical guidelines should consider the inter-relationship of stillbirth, PTB, and SGA, and that each condition is an independent risk factor for the other conditions.

TWEETABLE ABSTRACT

Risk of adverse birth outcomes in next pregnancy increases with the combined number of previous adverse events.

PLAIN LANGUAGE SUMMARY

Why and how was the study carried out? Each year, around 2.6 million babies are stillborn, 15 million are born preterm (<37 weeks of gestation), and 32 million are born small for gestational age (less than tenth percentile for weight, smaller than usually expected for the relevant pregnancy stage). Being born preterm or small for gestational age can increase the chance of long-term health problems. The effect of having a stillbirth, preterm birth, or small-for-gestational-age infant in a previous pregnancy on future pregnancy health has not been summarised. We identified 3399 studies of outcomes of previous pregnancies, and 17 were summarised by our study. What were the main findings? The outcome of the previous pregnancy influenced the risk of poor outcomes in the next pregnancy. Babies born to mothers who had a previous preterm birth or small-for-gestational-age birth were more likely to be stillborn. The smaller and the more preterm the previous baby, the higher the risk of stillbirth in the following pregnancy. The risk of stillbirth in the following pregnancy was doubled if the previous baby was born both preterm and small for gestational age. Babies born to mothers who had a previous stillbirth were more likely to be preterm or small for gestational age. What are the limitations of the work? We included a small number of studies, as there are not enough studies in this area (adverse birth outcomes followed by adverse cross outcomes in the next pregnancy). We found very few studies that compared the risk of small for gestational age after preterm birth or stillbirth. Definitions of stillbirth, preterm birth categories, and small for gestational age differed across studies. We did not know the cause of stillbirth for most studies. What are the implications for patients? Women who have a history of poor pregnancy outcomes are at greater risk of poor outcomes in following pregnancies. Health providers should be aware of this risk when treating patients with a history of poor pregnancy outcomes.

Cause of and factors associated with stillbirth: a systematic review of classification systems

INTRODUCTION

An estimated 2.6 million stillbirths occur worldwide each year. A standardized classification system setting out possible cause of death and contributing factors is useful to help obtain comparative data across different settings. We undertook a systematic review of stillbirth classification systems to highlight their strengths and weaknesses for practitioners and policymakers.

MATERIAL AND METHODS

We conducted a systematic search and review of the literature to identify the classification systems used to aggregate information for stillbirth and perinatal deaths. Narrative synthesis was used to compare the range and depth of information required to apply the systems, and the different categories provided for cause of and factors contributing to stillbirth.

RESULTS

A total of 118 documents were screened; 31 classification systems were included, of which six were designed specifically for stillbirth, 14 for perinatal death, three systems included neonatal deaths and two included infant deaths. Most (27/31) were developed in and first tested using data obtained from high-income settings. All systems required information from clinical records. One-third of the classification systems (11/31) included information obtained from histology or autopsy. The percentage where cause of death remained unknown ranged from 0.39% using the Nordic-Baltic classification to 46.4% using the Keeling system.

CONCLUSION

Over time, classification systems have become more complex. The success of application is dependent on the availability of detailed clinical information and laboratory investigations. Systems that adopt a layered approach allow for classification of cause of death to a broad as well as to a more detailed level.