Wisconsin Stillbirth Service Program: II. Analysis of diagnoses and diagnostic categories in the first 1,000 referrals

Stillbirth: we can do better

Stillbirth is far too common, occurring in millions of pregnancies per year globally. The rate of stillbirth (defined as death of a fetus prior to birth at 20 weeks' gestation or more) in the United States is 5.73 per 1000. This is approximately 1 in 175 pregnancies accounting for about 21,000 stillbirths per year. Although rates are much higher in low-income countries, the stillbirth rate in the United States is much higher than most high resource countries. Moreover, there are substantial disparities in stillbirth, with rates twice as high for non-Hispanic Black and Native Hawaiian or Other Pacific Islanders compared to non-Hispanic Whites. There is considerable opportunity for reduction in stillbirths, even in high resource countries such as the United States. In this article, we review the epidemiology, risk factors, causes, evaluation, medical and emotional management, and prevention of stillbirth. We focus on novel data regarding genetic etiologies, placental assessment, risk stratification, and prevention.

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.

Investigation and management of stillbirth: a descriptive review of major guidelines

Stillbirth is a common and devastating pregnancy complication. The aim of this study was to review and compare the recommendations of the most recently published guidelines on the investigation and management of this adverse outcome. A descriptive review of guidelines from the American College of Obstetricians and Gynecologists (ACOG), the Royal College of Obstetricians and Gynecologists (RCOG), the Perinatal Society of Australia and New Zealand (PSANZ), the Society of Obstetricians and Gynecologists of Canada (SOGC) on stillbirth was carried out. Regarding investigation, there is consensus that medical history and postmortem examination are crucial and that determining the etiology may improve care in a subsequent pregnancy. All guidelines recommend histopathological examination of the placenta, genetic analysis and microbiology of fetal and placental tissues, offering less invasive techniques when autopsy is declined and a Kleihauer test to detect large feto-maternal hemorrhage, whereas they discourage routine screening for inherited thrombophilias. RCOG and SOGC also recommend a complete blood count, coagulopathies' testing, anti-Ro and anti-La antibodies' measurement in cases of hydrops and parental karyotyping. Discrepancies exist among the reviewed guidelines on the definition of stillbirth and the usefulness of thyroid function tests and maternal viral screening. Moreover, only ACOG and RCOG discuss the management of stillbirth. They agree that, in the absence of coagulopathies, expectant management should be considered and encourage vaginal birth, but they suggest different labor induction protocols and different management in subsequent pregnancies. It is important to develop consistent international practice protocols, in order to allow effective determination of the underlying causes and optimal management of stillbirths, while identifying the gaps in the current literature may highlight the need for future research.

3137 fetuses in 33 years: What we have learned from the Wisconsin stillbirth service program

The Wisconsin Stillbirth Service Program (WiSSP) provided expert review by a dysmorphologist for community-acquired data on 3137 fetal deaths between 1983 and 2017. Intrinsic fetal causes were consistently identified in about 25% while placental and maternal causes were recognized with increasing frequency as attention was shifted from a primarily fetal to a multifocal approach. Identification of causes increased from 40% to 78% and in about half of cases results of the review altered recurrence risk and/or future pregnancy management. Banked data from WiSSP formed the basis of 24 publications, more than half of which have a genetic counselor and/or summer premedical student intern as an author. The earlier publications emphasized validation of the concept of community-based evaluation with central review, the utility of various parts of the WiSSP protocol, the similarity of second-trimester miscarriages <20 weeks to later stillbirths with respect to causes identified and recurrence risks, and the potential for results of etiologic evaluation to influence future prenatal care. The most important recurrent theme, however, was the interaction of intrinsic fetal, placental, and maternal factors in contributing to fetal demise. This implies that, at least in developed nations with available obstetric care, reduction in stillbirth will require careful attention to the myriad of factors contributing to fetal, placental, and maternal well-being.

Obstetric Care Consensus #10: Management of Stillbirth: (Replaces Practice Bulletin Number 102, March 2009)

Stillbirth is one of the most common adverse pregnancy outcomes, occurring in 1 in 160 deliveries in the United States. In developed countries, the most prevalent risk factors associated with stillbirth are non-Hispanic black race, nulliparity, advanced maternal age, obesity, preexisting diabetes, chronic hypertension, smoking, alcohol use, having a pregnancy using assisted reproductive technology, multiple gestation, male fetal sex, unmarried status, and past obstetric history. Although some of these factors may be modifiable (such as smoking), many are not. The study of specific causes of stillbirth has been hampered by the lack of uniform protocols to evaluate and classify stillbirths and by decreasing autopsy rates. In any specific case, it may be difficult to assign a definite cause to a stillbirth. A significant proportion of stillbirths remains unexplained, even after a thorough evaluation. Evaluation of a stillbirth should include fetal autopsy; gross and histologic examination of the placenta, umbilical cord, and membranes; and genetic evaluation. The method and timing of delivery after a stillbirth depend on the gestational age at which the death occurred, maternal obstetric history (eg, previous hysterotomy), and maternal preference. Health care providers should weigh the risks and benefits of each strategy in a given clinical scenario and consider available institutional expertise. Patient support should include emotional support and clear communication of test results. Referral to a bereavement counselor, peer support group, or mental health professional may be advisable for management of grief and depression.

Management of Stillbirth: Obstetric Care Consensus No, 10

Stillbirth is one of the most common adverse pregnancy outcomes, occurring in 1 in 160 deliveries in the United States. In developed countries, the most prevalent risk factors associated with stillbirth are non-Hispanic black race, nulliparity, advanced maternal age, obesity, preexisting diabetes, chronic hypertension, smoking, alcohol use, having a pregnancy using assisted reproductive technology, multiple gestation, male fetal sex, unmarried status, and past obstetric history. Although some of these factors may be modifiable (such as smoking), many are not. The study of specific causes of stillbirth has been hampered by the lack of uniform protocols to evaluate and classify stillbirths and by decreasing autopsy rates. In any specific case, it may be difficult to assign a definite cause to a stillbirth. A significant proportion of stillbirths remains unexplained even after a thorough evaluation. Evaluation of a stillbirth should include fetal autopsy; gross and histologic examination of the placenta, umbilical cord, and membranes; and genetic evaluation. The method and timing of delivery after a stillbirth depend on the gestational age at which the death occurred, maternal obstetric history (eg, previous hysterotomy), and maternal preference. Health care providers should weigh the risks and benefits of each strategy in a given clinical scenario and consider available institutional expertise. Patient support should include emotional support and clear communication of test results. Referral to a bereavement counselor, peer support group, or mental health professional may be advisable for management of grief and depression.

Aetiology and trends of rates of stillbirth in a tertiary care hospital in the north of India over 10 years: a retrospective study

OBJECTIVE

To analyse the aetiology of stillbirth and its changing trends in a single tertiary care referral institute of northern India over a 10-year period (2007-2016).

DESIGN

Retrospective study.

SETTING

Tertiary care hospital in the north of India.

SAMPLE

Medical records of all mothers who delivered a stillborn at the institute.

METHODS

Data was collected from monthly and annual perinatal audits and causes of stillbirths were classified using Simplified CODAC classification. Annual reduction rate was calculated by linear regression analysis and Cusick test for the changing trends over 9 years.

MAIN OUTCOME MEASURES

Of 54 160 births, 3678 babies were stillborn. Over 9 years, the annual stillbirth rate has reduced significantly from 73.6 to 62.0 per 1000 total births with an average annual reduction rate of 1%. The most common causes of stillbirths were hypertensive disorders of pregnancy (27.6%), antepartum haemorrhage (19.5%), and congenital anomalies (9.3%).

CONCLUSION

The annual reduction rate (1%) of stillbirth remains low. The aetiology of stillbirths remains unchanged over a 10-year period and hypertensive disorder of pregnancy remains the single most preventable cause of stillbirth.

TWEETABLE ABSTRACT

Analysis of stillbirths over a 10-year period in an Indian institute showed a high but declining trend with annual reduction rate of 1%.

Stillborn Infants: Associated Malformations

BACKGROUND

Stillbirth, defined as death of a fetus in utero after 20 weeks of gestation, occurs in 1 to 2% of pregnancies in the United States. Many of these stillborn infants have associated malformations, including chromosome abnormalities, neural tube defects, and malformation syndromes. Other causes are abnormalities of the placenta and maternal conditions, such as pre-eclampsia and obesity. A consecutive sample of malformed stillborn infants can establish the relative frequency and severity of the associated malformations.

METHODS

Stillbirths were identified in the Active Malformations Surveillance Program at Brigham and Women's Hospital (1972-2012). The findings at autopsy, including the findings in the placenta and the results of diagnostic studies, were compiled.

RESULTS

One hundred twenty-seven stillborn infants with malformations were identified at autopsy among 289,365 pregnancies, including trisomies 21, 18, and 13; 45,X; triploidy; anencephaly; lower urinary tract obstruction; holoprosencephaly and severe heart defects, such as hypoplastic left heart syndrome and tetralogy of Fallot with pulmonary atresia. The severity of the abnormalities in stillborn infants was more severe than the spectrum of abnormalities identified in live-born infants.

CONCLUSION

An autopsy of the stillborn fetus, including chromosome microarray and an examination of the placenta, can identify the underlying causes of the stillbirth. This review of stillborn fetuses with malformations showed that several different lethal malformations and heart defects are more common than among live-born infants. These postmortem examinations can improve the counseling of the parents about risks in future pregnancies. Birth Defects Research 110:114-121, 2018.© 2018 Wiley Periodicals, Inc.

Causes of Congenital Malformations

BACKGROUND

Many different causes of malformations have been established. The surveillance of a consecutive population of births, including stillbirths and elective terminations of pregnancy because of fetal anomalies, can identify each infant with malformations and determine the frequency of the apparent etiologies. This report is a sequel to the first such analysis in the first 10 years of this Active Malformations Surveillance Program (Nelson and Holmes, ).

METHODS

The presence of malformations was determined among 289,365 births over 41 years (1972-2012) at the Brigham and Women's Hospital in Boston. The abnormalities were identified from the review of the examination findings of the pediatricians and consultants and diagnostic testing for the live-born infants and the autopsies of the fetuses in elective terminations and stillbirths.

RESULTS

A total of 7020 (2.4%) infants and fetuses with one or more malformations were identified with these apparent etiologies in 26.6%: Mendelian disorders, including infants with postaxial polydactyly, type B; chromosome abnormalities; vascular disruption; complications of monozygous twinning; and environmental factors. The malformations of unknown etiology were a much larger group.

CONCLUSION

While several causes of malformations have been identified, many remain unexplained. Combining the ascertainment in a future surveillance programs with genome sequencing and chromosome microarray analysis will increase significantly the number of malformations attributed to genetic mechanisms. Birth Defects Research 110:87-91, 2018.© 2018 Wiley Periodicals, Inc.

Stillbirth and neonatal mortality in pregnancies complicated by major congenital anomalies: Findings from a large European cohort

OBJECTIVE

To provide prognostic information to help parents to reach an informed decision about termination or continuation of the pregnancy and to shape peripartum policy based on a large European cohort.

METHOD

Thirteen registries from the European Surveillance of Congenital Anomalies (EUROCAT) network contributed data from January 1, 1998, to December 31, 2011. Terminations for fetal anomalies were excluded. Chromosomal anomalies, syndromes and isolated anomaly groups were distinguished according to EUROCAT guidelines. Perinatal mortality, stillbirths, and early and late neonatal mortality rates (NMRs) were analyzed by anomaly group and gestational age.

RESULTS

Among 73 337 cases, perinatal mortality associated with congenital anomaly was 1.27 per 1000 births (95% confidence interval, 1.23-1.31). Average stillbirth rate was 2.68% (range 0%-51.2%). Early and late NMR were 2.75% (range 0%-46.7%) and 0.97% (range 0%-17.9%), respectively. Chromosomal anomalies and syndromes, and most isolated anomalies, had significant differences regarding timing of fetal demise compared to the general population. Chromosomal and central nervous system anomalies had higher term stillbirth rates.

CONCLUSIONS

We found relevant differences between anomalies regarding rates of stillbirth, NMR, and timing by gestational age. Our data can help parents to decide about their unborn child with a congenital anomaly and help inform maternal-fetal medicine specialists regarding peripartum management.

Major risk factors for stillbirth in different trimesters of pregnancy--a systematic review

Stillbirth remains an event that has an important impact on global health issues. Different levels of health care between countries suggest that the stillbirth rate may be one of the indicators of the quality of a country's medical system. In this review, major risk factors for stillbirth will be discussed, especially in different trimesters of pregnancy. Early identification of risk factors for stillbirth and appropriate antenatal management may reduce preventable stillbirths and improve general outcomes of pregnancy.

Foetal autopsy-categories and causes of death

INTRODUCTION

Intrauterine death(IUD)/ Stillbirth forms a major part of perinatal mortality which thereby is a good indicator of pregnancy wastage as well as quality of healthcare available. The key objectives of autopsy examination are to know the cause(s) of death, elucidation of pathogenic mechanism and quality control of clinical management. The aim of this study was to identify the prevalent causes of IUD, thereby taking appropriate measures to prevent them and decrease the perinatal mortality rate.

MATERIALS AND METHODS

The study included 14 cases of IUD received for autopsy in the Department of Pathology over a period of five years. Autopsies were performed as per standard protocol and included full anthropometric profile, external examination, gross and microscopic evaluation of different organs and placenta.

RESULTS

Total number of 14 fetal autopsies were performed over a period of 5 years. The causes were broadly classified as fetal, maternal and placental. Placental causes were seen in majority of cases (48.57%) followed by fetal (35.72%) and then maternal (21.42). Most prevalent cause of death was congenital anomalies (28.6%) followed by placental insufficiency (21.4%) and chorioamnionitis (14.2%).

CONCLUSION

Determination of causes of fetal death would prove beneficial to the clinicians and parents for better management and care in future pregnancies as well as in genetic counseling.

Indicated preterm birth for fetal anomalies

Between 2% and 3% of pregnancies are complicated by fetal anomalies. For most anomalies, there is no advantage to late preterm or early-term delivery. The risks of maternal or fetal complication are specific for each anomaly. Very few anomalies pose potential maternal risk. Some anomalies carry ongoing risks to the fetus, such as an increased risk of fetal death, hemorrhage, or organ damage. In a limited number of select cases, the advantages of late preterm or early-term birth may include avoiding an ongoing risk of fetal death related to the anomaly, allowing delivery in a controlled setting with availability of subspecialists and allowing direct care for the neonate with organ injury. The optimal gestational age for delivery cannot be determined for all pregnancies complicated by fetal anomalies. For most pregnancies complicated by anomalies, there is no change to obstetrical management regarding timing of delivery. For those that may benefit from late preterm or early-term delivery, variability exists such that each management plan should be individualized.

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.

Wisconsin stillbirth services program: a multifocal approach to stillbirth analysis

Stillbirth accounts for about 26,000 deaths annually in the US. In most previous studies, discrete causes are identified in less than half of all stillbirths. In order to identify causes and non-causal but potentially contributing abnormalities, we analyzed 416 of the most recent (2004-2010) Wisconsin Stillbirth Service Program (WiSSP) cases from a multifocal approach. In 70% of cases a cause sufficient to independently explain the demise was identified including 40% placental, 21.5% fetal, and 12.7% maternal. Results for stillbirths and second trimester miscarriages did not differ significantly. In 95% of cases at least one cause or non-causal abnormality was recognizable, and in two-thirds of cases, more than one cause or non-causal abnormality was identified. In cases with maternal cause, the placenta was virtually always abnormal. Both placentas (59%) and fetuses (38%) were frequently smaller than expected for gestational age. Previous miscarriage and/or stillbirth were risk factors for second and third trimester losses, with 35% of previous pregnancies ending in fetal demise. Recommendations include complete evaluation of all second and third trimester losses with special attention to placental pathology and thorough investigation for multiple causes or abnormalities whether or not a primary cause is initially recognized. Improved understanding of the causes of late miscarriage and stillbirth may contribute to recognition and management of pregnancies at risk and eventually to prevention of stillbirth.

Cytogenetic analysis of 355 cases of fetal loss in different trimesters

OBJECTIVE

We estimated the success rates of cytogenetic analyses in different tissue samples after intrauterine fetal deaths and analyzed the value of cytogenetic testing for determining the causes.

METHODS

Women with intrauterine fetal deaths (occurring at > 10 weeks of gestation) were offered either invasive testing before medical induction of labor, or solid tissue biopsy diagnosis after delivery.

RESULTS

A total cohort of 355 intrauterine fetal deaths was studied. During antepartum examinations, invasive procedures included amniocentesis (AMC), chorionic villus sampling (CVS) and umbilical cord (UBC) sampling. During postpartum examinations, samples were taken from unfixed specimens of fetal skin, placenta and other tissues. Chromosomal abnormalities were observed in 22 fetal deaths for which cytogenetic analyses were successful. Logistic regression analysis identified antepartum invasive sampling [P = 0.000, odds ratio (OR) 31.125, 95% confidence interval (CI) 14.265-67.908] to be associated with a high cytogenetic success rate and older age with fetal deaths (P = 0.104, OR 0.487, 95% CI 0.204-1.160) not to be associated with a high chromosomal abnormality. In the patients with recurrent pregnancy loss, the chromosomal abnormality rate of 18.6% of spontaneous abortions has not been significantly more than that of fetal deaths 11.5% (P = 0.437).

CONCLUSION

Parents should be counseled on all aspects of cytogenetic analysis after fetal death. Antepartum testing after pregnancy loss is recommended.

Genetics of stillbirth

Approximately 25% of stillbirths have been attributed to genetic etiologies. The most common cytogenetic abnormalities are similar to those seen in liveborns and include 45X, trisomy 21, trisomy 18, and trisomy 13. Cytogenetic abnormalities are more common when fetal structural anomalies are identified. Mendelian and metabolic causes of stillbirth are less well understood although single gene disorders can result in stillbirth. With new cytogenetic and molecular technologies additional genetic causes of stillbirth are likely to be described and will provide additional information for appropriate genetic counseling.

Stillbirth: fetal disorders

Fetal disorders (including congenital malformations) are among the most frequent of causes of intrauterine death. Assessment to detect fetal processes is straightforward: history (prenatal, perinatal, and family); external clinical examination; photographs; whole body radiographs; cytogenetic investigation; and internal necropsy. Unfortunately such investigations are profoundly underused. When appropriately and nonselectively assessed, about one-fifth of all stillborn infants will be found to have a fetal cause of their death. Fetal diagnoses are markedly heterogeneous, with no single process accounting for more than 1.5% of all fetal deaths. Identifying a fetal cause has marked implications for the family and changes some elements of counseling and care in more than half of those whose stillborn infants were adequately evaluated. Currently unmet needs include research needs including efforts to understand the variability of intrauterine effects of fetal disorders and their causes, and clinical needs, particularly related to funding for evaluation of stillborns and development of geographically dispersed multidisciplinary commitment and expertise devoted to stillbirth evaluation.

Evidence of maternal platelet activation, excessive thrombin generation, and high amniotic fluid tissue factor immunoreactivity and functional activity in patients with fetal death

OBJECTIVE

Fetal death can lead to disseminated intravascular coagulation or fetal death syndrome. However, currently it is not clear what are the changes in the coagulation system in patients with a fetal death without the fetal death syndrome. This study was undertaken to determine: (1) whether fetal death in the absence of fetal death syndrome is associated with changes in hemostatic markers in maternal plasma and amniotic fluid; and (2) whether maternal hypertension or placental abruption are associated with further changes in the hemostatic profile of these patients.

METHODS

A cross-sectional study included the following: (1) determination of changes in markers of coagulation and platelet activation in patients with a normal pregnancy (n = 71) and patients with fetal demise (FD) without disseminated intravascular coagulation (n = 65); (2) determination of the amniotic fluid (AF)-tissue factor concentration and activity, as well as the concentrations of thrombin-antithrombin III (TAT) complexes in patients with a normal pregnancy (n = 25) and those with a FD (n = 36) who underwent amniocentesis. Plasma and AF concentrations of TAT complexes and TF (an index of thrombin generation), as well as maternal plasma concentrations of sCD40L (a marker of platelet activation), tissue factor pathway inhibitor (TFPI) and prothrombin fragments (PF) 1 + 2 (also an indicator of in vivo thrombin generation) were measured by ELISA. TF and TFPI activity were measured using chromogenic assays.

RESULTS

(1) patients with FD without hypertension had a higher median maternal plasma sCD40L concentration than normal pregnant women (P < 0.001); (2) patients with FD had a higher median maternal plasma TAT III complexes than women with a normal pregnancy (P < 0.001); (3) the median AF-TF concentration and activity were higher in the FD group than in the normal pregnancy group (P < 0.001 for both); (4) patients with preeclampsia and FD had a higher median maternal plasma immunoreactive TF concentration than both normotensive patients with FD and women with normal pregnancies (P < 0.001 and P = 0.001, respectively); (5) the median plasma TF activity was higher in patients with preeclampsia and FD than that of women with normal pregnancies (P = 0.003); (6) among patients with a FD, those with placental abruption had a higher median AF-TAT complexes concentration than those without abruption (P = 0.0004).

CONCLUSIONS

Our findings indicate that: (1) mothers with a FD have evidence of increased in vivo thrombin generation and platelet activation than women with normal pregnancies; (2) patients with a FD and hypertension had a higher degree of TF activation than those with fetal death but without hypertension; (3) the AF of women with a FD had a higher median TF concentration and activity than that of normal pregnant women. AF can be a potential source for tissue factor and it participates in the development of fetal death syndrome in patients with a retained dead fetus.

Array-based comparative genomic hybridization (aCGH) in the genetic evaluation of stillbirth

This study examined the utility of array-based comparative genomic hybridization (aCGH) in detecting genetic abnormalities associated with late pregnancy loss. Comparisons were made with classic cytogenetics to test whether aCGH represents a superior methodology for the clinical evaluation of stillbirth. Stillborn infants were selected for aCGH testing from the Wisconsin Stillbirth Service Program (WiSSP) database and tissue bank, based on abnormal clinical findings (presence of at least two abnormalities of two different organs or parts of the body). aCGH analysis was successfully completed in 15 cases which met the clinical criteria and for which sufficient amount of high quality DNA was recovered from archival material. The testing was performed using commercially available 1 Mb BAC arrays. Among 15 tested stillborns, aCGH detected two abnormalities (trisomy 21 and an unbalanced translocation between chromosomes 3 and 10), for an overall detection rate of 13% in stillborns with malformations who had normal or unobtainable cytogenetic results. This preliminary study supports the clinical value of aCGH testing in diagnostic evaluation of stillborns with congenital anomalies.

Stillbirth classification--developing an international consensus for research: executive summary of a National Institute of Child Health and Human Development workshop

Stillbirth is a major obstetric complication, with 3.2 million stillbirths worldwide and 26,000 stillbirths in the United States every year. The Eunice Kennedy Shriver National Institute of Child Health and Human Development held a workshop from October 22-24, 2007, to review the pathophysiology of conditions underlying stillbirth to define causes of death. The optimal classification system would identify the pathophysiologic entity initiating the chain of events that irreversibly led to death. Because the integrity of the classification is based on available pathologic, clinical, and diagnostic data, experts emphasized that a complete stillbirth workup should be performed. Experts developed evidence-based characteristics of maternal, fetal, and placental conditions to attribute a condition as a cause of stillbirth. These conditions include infection, maternal medical conditions, antiphospholipid syndrome, heritable thrombophilias, red cell alloimmunization, platelet alloimmunization, congenital malformations, chromosomal abnormalities including confined placental mosaicism, fetomaternal hemorrhage, placental and umbilical cord abnormalities including vasa previa and placental abruption, complications of multifetal gestation, and uterine complications. In all cases, owing to lack of sufficient knowledge about disease states and normal development, there will be a degree of uncertainty regarding whether a specific condition was indeed the cause of death.

Challenges and priorities for surveillance of stillbirths: a report on two workshops

Stillbirths, those with and without birth defects, are an important public health topic. The National Center on Birth Defects and Developmental Disabilities at the Centers for Disease Control and Prevention conducted two workshops during April and July 2005. Both workshops explored the challenges of conducting surveillance of stillbirths. Workshop participants considered an approach that added the surveillance of stillbirths, those with and without birth defects, as part of existing population-based birth defects surveillance programs in Iowa and Atlanta. The workshops addressed three key aspects for expanding birth defects programs to conduct active, population-based surveillance on stillbirths: (1) case identification and ascertainment, (2) data collection, and (3) data use and project evaluation. Participants included experts in pediatrics, obstetrics, epidemiology, maternal-fetal medicine, perinatology and pediatric pathology, midwifery, as well as practicing clinicians and pathologists. Expanding existing birth defects surveillance programs to include information of stillbirths could potentially enhance the data available on fetal death reports and also could benefit such programs by improving the ascertainment of birth defects.

Etiology of stillbirth at term: a 10-year cohort study

OBJECTIVE

To examine etiological factors contributing to cases of intrauterine fetal demise in term pregnancies over a 10-year period.

METHODS

This was a retrospective cohort analysis of 29 908 term (37(+0) to 41(+6) weeks gestation) infants delivering in a single tertiary-referral university institution over the 10-year period from 1996 to 2005. Cases of stillbirth were identified from a computerized hospital database, and pathological, clinical, and biochemical data were reviewed for all cases. Trends were analyzed using the Cusick test for trend. Categorical data were analyzed using the Fisher's exact test, with the 5% level considered significant.

RESULTS

The incidence of intrauterine fetal demise at term was 1.8 per 1000 at-risk pregnancies. There was no significant downward trend in the rate of term stillbirth between 1996 and 2005 (p = 0.0808). Stillbirths were unexplained in 51% of cases, although in many cases a possible etiological factor was identified but not necessarily proven. There was a significant downward trend in the incidence of unexplained term stillbirths at our institution over the 10-year study period (p = 0.0105). Placental/cord factors accounted for 25% of term stillbirths and did not decrease significantly over the study period (p = 0.0953). Almost 50% of term stillbirths occurred in women who registered late or had no antenatal care. However, suboptimal antenatal care was not predictive of differences in either acceptance of perinatal postmortem or successful identification of stillbirth etiology.

CONCLUSIONS

The incidence of stillbirth at term is 2 per 1000 term pregnancies and has not changed significantly in the past 10 years. Almost 50% of term stillbirths occurred in women with suboptimal antenatal care. More than half of cases are unexplained, often resulting from an incomplete diagnostic work-up. Despite this, there has been a significant downward trend in the rates of unexplained stillbirth at term. It is imperative that a complete diagnostic work-up is performed in cases of term stillbirth, to minimize the incidence of unexplained stillbirth.

Fetal death certificates as a source of surveillance data for stillbirths with birth defects

OBJECTIVE

We assessed fetal death certificates (FDCs) as a source of surveillance for stillbirths with birth defects by linkage with data from the Metropolitan Atlanta Congenital Defects Program (MACDP), a population-based birth defects surveillance system.

METHODS

Stillbirths with defects in MACDP were identified from 1994 through 2002 and linked to FDCs. Sensitivity of FDCs for capturing stillbirths with defects was estimated, and predictors for a case being reported were assessed. Concordance for selected variables from each data source was evaluated. RESILTS: Two hundred twenty-four of 257 stillbirths with birth defects in MACDP were linked to an FDC (linkage rate = 87.2%; 95% confidence interval [CI] 82.4, 91.0). Stillbirths of non-Hispanic black and Hispanic/other mothers were more likely to be issued an FDC (odds ratio [OR] = 5.6 [95% CI 1.9, 17.0] and 14.0 [95% CI 1.7, 114.0], respectively). Cases undergoing autopsy were more likely to be issued an FDC (OR = 3.2; 95% CI 1.1, 8.7). Performance of an amniocentesis was poorly recorded on FDCs. The sensitivity and positive predictive value of FDCs for selected classes of defects ranged from 10% to 70% and 25% to 93%, respectively.

CONCLUSIONS

Compared to FDCs, MACDP's active case identification improves the ascertainment of stillbirths with birth defects and the quality of certain recorded data.

Comparison of fetal demise case series drawn from socioeconomically distinct counties in New Jersey

The causes of stillbirth were investigated in two case series drawn from distinct communities within the same geographic region in New Jersey, one characterized by affluence (Hackensack Medical Center, Bergen County) and one by poverty (University Hospital, Essex County). The data was obtained over 4 years (1998-2001) from a stillbirth autopsy service available to all obstetrics-gynecology clinicians in the northern New Jersey area. A total of 52 stillbirths from University Hospital in Newark (Essex County) and 55 from Hackensack Medical Center (Bergen County) were examined by this same autopsy service. Cause(s) were identified for 70% of stillbirth cases. Whereas population-based data revealed that the rate of stillbirths was higher in Essex and mothers of stillbirths in Essex were of younger age, greater parity, and gravidity and had higher rates of smoking, single marital status, and very low birth weight infants, the only significant difference between the two case series was infection, detected in 35% of stillbirths from University Hospital versus 14% from Hackensack. Also no difference in the incidence of stillbirth due to unknown cause was found between the case series.

Guidelines for Investigating Stillbirths: An Update of a Systematic Review

OBJECTIVE

To identify formal, publicly available guidelines for stillbirth investigation and to identify the most appropriate clinical practice guideline (or component of a guideline) for use in Alberta.

METHODS

A systematic literature search was conducted to identify primary and secondary research studies published between January 1985 and August 2006 and formal, publicly available guidelines on the subject of stillbirth investigation. The Cochrane Library, PubMed, EMBASE, CINAHL, HealthSTAR, Science Citation Index, BIOSIS, and the NHS and CRD databases were searched. The methodological quality of the selected primary research studies was assessed according to specific criteria.

RESULTS

All six of the publicly available clinical practice guidelines selected for this review outlined similar steps in the stillbirth investigation but differed about which tests to include and which components should be core or additional investigations. They agreed on including several elements for routine investigation, such as complete autopsy and detailed examination of the cord and placenta. Of 61 retrieved primary research studies, only seven met the inclusion criteria. No studies compared the value of specific guidelines. Although reviewed evidence highlights the value of fetal autopsy and placental examinations as integral components of stillbirth investigation, the value of other components is still not clear.

CONCLUSIONS

No firm scientific judgement could be made about which clinical practice guideline for stillbirth investigation is the most appropriate or which components are essential. Currently here is no generally accepted reference guideline for stillbirth investigation. Fetal autopsy and placental examination remain important components, assuming the postmortem examination is of high quality. These data may be helpful in counselling parents who are considering whether or not to consent to a postmortem examination.

Work-up of stillbirth: a review of the evidence

Despite improvements in antenatal and intrapartum care, stillbirth, defined as in utero fetal death at 20 weeks of gestation or greater, remains an important, largely unstudied, and poignant problem in obstetrics. More than 26,000 stillbirths were reported in the United States in 2001. Although several conditions have been linked to stillbirth, it is difficult to define the precise etiology in many cases. This paper reviews known and suspected causes of stillbirth including genetic abnormalities, infection, fetal-maternal hemorrhage, and a variety of medical conditions in the mother. The proportion of stillbirths that have a diagnostic explanation is higher in centers that conduct a defined and systematic evaluation. The evidence for recommended diagnostic tests for stillbirth are discussed. The ongoing work of the National Institute of Child Health and Human Development Stillbirth Collaborative Research Network, a consortium of 5 academic centers in the United States that are studying the scope and causes of stillbirth, is presented.

Fetal Death

The death of a formed fetus is one of the most emotionally devastating events for parents and clinicians. With improved care for conditions such as RhD alloimmunization, diabetes, and preeclampsia, the rate of fetal death in the United States decreased substantially in the mid twentieth century. However, the past several decades have seen much greater reductions in neonatal death rates than in fetal death rates. As such, fetal death remains a significant and understudied problem that now accounts for almost 50% of all perinatal deaths. The availability of prostaglandins has greatly facilitated delivery options for patients with fetal death. Risk factors for fetal death include African American race, advanced maternal age, obesity, smoking, prior fetal death, maternal diseases, and fetal growth impairment. There are numerous causes of fetal death, including genetic conditions, infections, placental abnormalities, and fetal-maternal hemorrhage. Many cases of fetal death do not undergo adequate evaluation for possible causes. Perinatal autopsy and placental examination are perhaps the most valuable tests for the evaluation of fetal death. Antenatal surveillance and emotional support are the mainstays of subsequent pregnancy management. Outcomes may be improved in women with diabetes, hypertension, red cell alloimmunization, and antiphospholipid syndrome. However, there is considerable room for further reduction in the fetal death rate.

Risk factors for unexplained antepartum fetal death in Norway 1967-1998

OBJECTIVE

To relate unexplained antepartum fetal death with maternal and fetal characteristics in order to identify risk factors.

DESIGN

Population-based study based on records of 1,676,160 singleton births with gestational age > or =28 weeks. Unexplained antepartum fetal death was defined as fetal death before labour without known fetal, placental, or maternal pathology.

RESULTS

Although unexplained fetal mortality in general declined from 2.4 per 1000 births in 1967-1976 to 1.6 in 1977-1998, the proportion among all fetal deaths increased from 30% to 43% during the same period of observation. Unexplained fetal death occurred later in gestation than explained. From 39 weeks of gestation, the risk increased progressively to 50/10,000 in women aged > or =35 years and <10/10,000 in women <25 years. In birth order > or =5, the risk was particularly high after 39 weeks of gestation. For birth weight percentile 2.5-9.9 and > or =97.5, unexplained fetal death was four and three times more likely to occur, respectively. We found an additive effect of maternal age and birth weight percentile 2.5-9.9. Women with less than 10 years education had higher risk than women with 13 years or more (OR=1.6). Weaker associations were observed with female gender, unmarried mothers, and winter season.

CONCLUSIONS

Unexplained antepartum fetal death occurred later in gestation than explained and was associated with high maternal age, multiparity, low education, and moderately low and high birth weight percentile. The increased risk in post-term pregnancies and the additive effect of maternal age and birth weight percentile 2.5-9.9 suggests that older women would benefit from monitoring of fetal growth.

Unexplained antepartum fetal death in Norway, 1985-97: diagnostic validation and some epidemiologic aspects

OBJECTIVE

To validate the diagnosis of an unexplained antepartum fetal death in the Medical Birth Registry of Norway against data obtained from hospital records, alone and combined with autopsy data. To compare epidemiologic characteristics of an unexplained fetal death based on cases recorded by the three data sources.

METHODS

Data on unexplained fetal deaths in the Registry were compared with clinical and autopsy data from 108 457 singletons with a gestational age >or= 28 weeks or a birthweight >or= 1000 g delivered in 1985-97 at Haukeland Hospital in Bergen and Aker Hospital in Oslo.

RESULTS

Compared with clinical data, the positive and negative predictive values of a Registry diagnosis of an unexplained fetal death were 88% and 86%, respectively, while the sensitivity and specificity were 76% and 93%, respectively. Compared with clinical and autopsy data combined, the positive and negative predictive values of a Registry diagnosis of an unexplained fetal death were 77% and 89%, respectively, while the sensitivity and specificity were 78% and 88%, respectively. High agreement was observed in comparisons between the data sources of risks according to various independent variables.

CONCLUSIONS

The validity of a diagnosis of an unexplained antepartum fetal death based on the Medical Birth Registry of Norway is sufficiently high to justify future large-scale epidemiologic studies based on this database.

Genetics and metabolic causes of stillbirth

Approximately 25% of stillbirths have been attributed to cytogenetic, mendelian, or biochemical causes with 75% still unknown. The most common autosomal trisomies are 21, 18, and 13, and the most common karyotypic abnormality is 45x. The remaining are sporadic multiple malformation syndromes and single organ malformations. Little is known about the genetic and metabolic causes of stillbirth; however, with new cytogenetic techniques such as fluorescent in situ hybridization, comparative genomic hybridization, and telomeric probes, cytogenetic errors will be identified more accurately. Advances in diagnosis will provide additional information for appropriate genetic counseling.

Clinical value of postnatal autopsy and genetics consultation in fetal death

The aim of the present study was to investigate the clinical use of postnatal autopsy and genetics consultation in cases of fetal death in a teaching hospital. A retrospective analysis of medical records including pathology and genetics reports was performed in all cases of fetal death in which a woman delivered at Ben Taub General Hospital, Houston, Texas over a 2-year period. Cases were excluded when gestational age of the fetus was less than 20 weeks. Fetuses were only included when the 1- and 5-min Apgar scores were 0 and 0, respectively. There were 139 fetal deaths and 12,209 live born infants during the study period (stillbirth rate 1.125%). Although pathology services were used in 96.2%, a genetics consultation was obtained in only 12% of cases. Fetal autopsy provided a certain cause of fetal death in 19.4%, a probable cause for death in 36.3%, and was inconclusive in 44.3%. Among the cases in which a genetics consultation was obtained, a certain and probable cause for fetal death was found in 20% and 20% of cases, respectively. The utilization of genetics consultation was found to be independent of multiple clinical variables examined including ultrasound data, identification of maceration, and training level of resident. Our data show a frequent use of pathologic examination in cases of fetal death and an infrequent use of genetics consultation services. The request for genetics consultation seemed to have been made at random.

Risk of stillbirth in offspring of men exposed to ionising radiation

Radiation genetic risk models are employed to predict the frequency of radiation-related stillbirths to partners of occupationally exposed male workers, using the incidence data recently reported by Parker et al from an epidemiological study of Cumbrian births. Expanding on previously developed conservative risk estimates suggests that, of the 130 observed stillbirths to partners of male radiation workers, 0.3 cases would be attributable to paternal preconceptional irradiation, in contrast to the 17.5 (95% confidence interval: 3.1 to 31.9) cases predicted by Parker et al from their preferred dose-response model. The incompatibility of the results reported by Parker et al with those from other investigations, both epidemiological and experimental, and the inability of the study to consider a number of factors which might affect stillbirth rates, particularly those relating to the mother, make it difficult to accept that paternal irradiation received occupationally could have contributed to a detectable increase in stillbirths.

Risk for birth defects among premature infants: a population-based study

OBJECTIVE

To investigate the relationship between prematurity and birth defects.

STUDY DESIGN

In a population-based cohort study, infants with birth defects were ascertained through the Metropolitan Atlanta Congenital Defects Program, a surveillance system with active methods of ascertainment. Gestational age data were obtained from birth certificates of liveborn, singleton infants with and without birth defects born in the 5-county metropolitan Atlanta area.

RESULTS

Among 264,392 infants with known gestational ages born between 1989 and 1995, 7738 were identified as having birth defects (2.93%). Premature infants (<37 weeks' gestation) were more than two times as likely to have birth defects than term infants (37-41 weeks) (risk ratio = 2.43; 95% CI 2.30-2.56). This relationship was evident for several categories of birth defects. The rate of birth defects varied by gestational age categories, with the highest risk in the 29- to 32-week gestational age category (risk ratio = 3.37).

CONCLUSIONS

The risk for birth defects is increased in premature infants. Awareness of this relationship is important for clinicians caring for premature infants. The morbidity and mortality associated with a particular defect may be significantly altered by the presence of prematurity. Further study of this association may provide insight into the etiology of these relatively common problems.