Unexplained Antepartum Stillbirth Research Articles

Identification of the optimal growth chart and threshold for the prediction of antepartum stillbirth.

To evaluate the effect of the choice growth chart and threshold used to define small for gestational age (SGA) on the predictive value of SGA for placenta-related or unexplained antepartum stillbirth. A retrospective cohort study of all women with a singleton pregnancy who gave birth > 24week gestation in a single center (2000-2016). The exposure of interest was SGA, defined as birth weight < 10th or < 25th centile according to three fetal growth charts (Hadlock et al., Radiology 181:129-133, 1991; intergrowth-21st (IG21), WHO 2017, and a Canadian birthweight-based reference-Kramer et al., Pediatrics 108:E35, 2001). The outcome of interest was antepartum stillbirth due to placental dysfunction or unknown etiology. Cases of stillbirth attributed to other specific etiologies were excluded. A total of 49,458 women were included in the cohort. There were 103 (0.21%) cases of stillbirth due to placental dysfunction or unknown etiology. For cases in the early stillbirth cluster (≤ 30weeks), the detection rate was high and was similar for the three ultrasound-based fetal growth charts of Hadlock, IG21, and WHO (range 83.3-87.0%). In contrast, the detection rate of SGA for cases in the late stillbirth cluster (> 30weeks) was low, being highest for WHO and Hadlock (36.7% and 34.7%, respectively), and lowest for IG21 (18.4%). Using a threshold of the 25th centile increased the detection rate for stillbirth by approximately 15-20% compared with that achieved by the 10th centile cutoff. At > 30week gestation, the Hadlock or WHO fetal growth charts provided the best balance between detection rate and false positive rate for stillbirth.

Assessing the deprivation gap in stillbirths and neonatal deaths by cause of death: a national population-based study

ObjectiveTo investigate socioeconomic inequalities in cause-specific stillbirth and neonatal mortality to identify key areas of focus for future intervention strategies to achieve government ambitions to reduce mortality rates.DesignRetrospective cohort study.SettingEngland,...

Stillbirths in Jordan: rate, causes, and preventability

Objectives: This study aimed to determine the stillbirth rate in Jordan and to determine the leading causes of stillbirths. Analyzing the stillbirth data from a large sample size of Jordanian women would be very valuable for planning the resources and improving the services.Methods: The data from the national study of perinatal mortality in Jordan were analyzed. A total of 21,980 women who delivered at a gestational age ≥20 weeks in any of the 18 selected hospitals during the study period (March 2011–April 2012) were analyzed. The stillbirth rate was calculated as the number of stillbirths per 1000 total births. The deaths were also classified according to NICE classification system.Results: The rates of stillbirths were 11.6/1000 total births born after 20 weeks of gestation, 11.2/1000 total births born ≥22 weeks of gestation, 10.6/1000 total births born ≥24 weeks of gestation, and 9.0/1000 total births born ≥28 weeks of gestation. According to NICE classification, the main causes of stillbirths were maternal diseases (19.5%), unexplained immaturity (18.8%), congenital anomalies (17.6%), unexplained antepartum stillbirths (17.6%), obstetric complications (8.4%), placental abruption (5.7%), and multiple births (5%). The expert Panel judged that 34.5% of all fetal deaths were preventable and 30.3% were possibly preventable with optimal care.Conclusions: This study highlighted stillbirth risks in Jordan, which could encourage maternal–infant health-care providers, other researchers, policymakers, and stakeholders to implement solutions and to develop a feasible intervention.

Unravelling caesarean delivery as a risk factor for antepartum stillbirth.

Caesarean delivery rates have remained persistently high in many high-income countries (Gibbons, World Health Report (2010) Background Paper, No 30). The performance of a caesarean delivery impacts the management of subsequent pregnancies, increasing the likelihood of repeat caesarean delivery. This article reports intriguing results indicating that caesarean delivery in the first pregnancy is an independent risk factor for unexplained antepartum stillbirth in the second pregnancy. The few studies examining previous caesarean delivery as a risk factor for stillbirth have had conflicting results and have limited information available on the cause of the stillbirth. The authors found in a cohort of 128 585 singleton births, an overall 1.5-fold increased risk for unexplained stillbirth at 24 weeks of gestation and beyond in women with previous caesarean delivery and 1.9-fold increase for stillbirth at or after 34 weeks of gestation. A database of all births in Scotland with information on clinical, demographic characteristics and outcomes was linked to the Scottish Stillbirth and Infant Death Survey, a national registry that routinely classifies all perinatal deaths in Scotland based on clinical information obtained from local coordinators and pathologists. The association between previous caesarean delivery and unexplained stillbirth persisted when limited to women whose first birth was at term and regardless of labour duration. In addition to the use of databases containing high-quality data on important covariates, there are other strengths of this study. The cause of stillbirth was uniformly classified using a modification of the Wigglesworth classification. Deaths were classified by a single medically qualified individual, who had access to postnatal investigations and autopsy when performed. Furthermore, small-for-gestational-age birthweight was not regarded as a cause of stillbirth, which is important because in some classification systems it is considered a cause without regard to the true ‘cause’, i.e. the underlying condition that led to small for gestational age resulting in stillbirth. Confirmation through a meta-analysis of three other adequate quality studies bolsters the findings of this study of previous caesarean delivery as a risk factor for antepartum stillbirth. As the authors correctly point out, the absolute risk difference is only 0.1%; 1000 caesarean deliveries would need to be avoided to prevent one additional antepartum stillbirth. However, there are important avenues of future research with potential clinical impact resulting from this study. The potential biological plausibility of an underlying mechanism of abnormal placentation resulting in the increased risk of antepartum stillbirth is important. Caesarean delivery involves the creation of a uterine scar, which is associated with abnormalities of the placenta (e.g. abruption and morbidly adherent placenta), and may affect implantation. Therefore, it is possible that previous caesarean delivery could lead to abnormal placental function leading to stillbirth. The very few women in whom the scar induces impaired placentation could be investigated by ultrasound in their next pregnancy, which might serve to identify women at increased risk. Understanding the physiological changes in uterine blood flow in a subsequent pregnancy in women with a previous caesarean delivery may shed light on placentally based adverse pregnancy outcomes in general. None declared. Completed disclosure of interests form available to view online as supporting information. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Previous caesarean delivery and the risk of unexplained stillbirth: retrospective cohort study and meta-analysis.

To determine whether caesarean delivery in the first pregnancy is a risk factor for unexplained antepartum stillbirth in a second pregnancy. A population-based retrospective cohort study and meta-analysis. All maternity units in Scotland. A cohort of 128585second births, 1999-2008. Time-to-event analysis and random-effects meta-analysis. Risk of unexplained antepartum stillbirth in a second pregnancy. There were 88 stillbirths among 23688 women with a previous caesarean delivery (2.34 per 10000 women per week) and 288 stillbirths in 104897 women who had previously delivered vaginally (1.67 per 10000 women per week, P=0.002). When analysed by cause, women with a previous caesarean delivery had an increased risk of unexplained stillbirth (hazard ratio, HR1.47; 95% confidence interval, 95%CI 1.12-1.94; P=0.006) and, as previously observed, the excess risk was apparent from 34weeks of gestation onwards. The risk did not differ in relation to the indication of the caesarean delivery, and was independent of maternal characteristics and previous obstetric complications. We identified three other comparable studies (two in North America and one in Europe), and meta-analysis of these studies showed a statistically significant association between previous caesarean delivery and the risk of antepartum stillbirth in the second pregnancy (pooled HR1.40; 95%CI 1.10-1.77; P=0.006). Women who have had a previous caesarean delivery are at increased risk of unexplained stillbirth in the second pregnancy. Caesarean first delivery is associated with an increased risk of unexplained stillbirth in the next pregnancy.

PM.105 Evaluation of 10 Year Term Stillbirth Data in a Large UK Tertiary Unit Serving a Multiethnic Population

Stillbirths at term can be devastating for both parents and obstetrician. In most cases the cause is unexplained.MethodRetrospective review of cases from 2000–2010 at a large UK teaching hospital. 220...

Unexplained antepartum stillbirth: A consequence of placental aging?

Unexplained antepartum stillbirth is a major obstetric health problem. Data demonstrate a rapid rise in risk per 1000 continuing pregnancies as gestation advances beyond 40 weeks. We review the evidence that such stillbirths are a consequence of aging related changes in the late gestation placenta. We suggest that the relatively small number of continuing pregnancies after 40 completed weeks means that negative effects of genes that produce aging affect so few pregnancies that polymorphisms in genes that produce these effects are retained in the population. Aging related changes likely represent a consequence of the damaging effects of oxidative stress, increased by cigarette smoking counteracted by the mitigating effects of oxidative defence pathways. The aging related changes are likely downstream from nutrient sensing units such as mTOR and include effects on production of telomerase and consequent shortening of telomere length. The late gestation changes occur in the context of increasing fetal growth and nutrient supply demands that can produce the rapid development of a mismatch between placental supply and fetal need resulting in fetal demise. Premature aging may also play an important role in antepartum stillbirth occurring earlier in pregnancy, especially in the context of growth restriction.

Causes of perinatal death at a tertiary care hospital in Northern Tanzania 2000–2010: a registry based study

BackgroundPerinatal mortality reflects maternal health as well as antenatal, intrapartum and newborn care, and is an important health indicator. This study aimed at classifying causes of perinatal death in order to identify categories of potentially preventable deaths.MethodsWe studied a total of 1958 stillbirths and early neonatal deaths above 500 g between July 2000 and October 2010 registered in the Medical Birth Registry and neonatal registry at Kilimanjaro Christian Medical Centre (KCMC) in Northern Tanzania. The deaths were classified according to the Neonatal and Intrauterine deaths Classification according to Etiology (NICE).ResultsOverall perinatal mortality was 57.7/1000 (1958 out of 33 929), of which 1219 (35.9/1000) were stillbirths and 739 (21.8/1000) were early neonatal deaths. Major causes of perinatal mortality were unexplained asphyxia (n=425, 12.5/1000), obstetric complications (n=303, 8.9/1000), maternal disease (n=287, 8.5/1000), unexplained antepartum stillbirths after 37 weeks of gestation (n= 219, 6.5/1000), and unexplained antepartum stillbirths before 37 weeks of gestation (n=184, 5.4/1000). Obstructed/prolonged labour was the leading condition (251/303, 82.8%) among the obstetric complications. Preeclampsia/eclampsia was the leading cause (253/287, 88.2%) among the maternal conditions. When we excluded women who were referred for delivery at KCMC due to medical reasons (19.1% of all births and 36.0% of all deaths), perinatal mortality was reduced to 45.6/1000. This reduction was mainly due to fewer deaths from obstetric complications (from 8.9 to 2.1/1000) and maternal conditions (from 8.5 to 5.5/1000).ConclusionThe distribution of causes of death in this population suggests a great potential for prevention. Early identification of mothers at risk of pregnancy complications through antenatal care screening, teaching pregnant women to recognize signs of pregnancy complications, timely access to obstetric care, monitoring of labour for fetal distress, and proper newborn resuscitation may reduce some of the categories of deaths.

OP45 Caesarean Section and Subsequent Fetal Death: Systematic Review and Meta-Analysis

BackgroundSpontaneous miscarriage (the death of a fetus before 20 weeks of pregnancy), occurs in 10–15% of recognised pregnancies. Stillbirth (the death of a fetus after 24 weeks of pregnancy), occurs...

Socioeconomic inequalities in the rate of stillbirths by cause: a population-based study

ObjectiveTo assess time trends in socioeconomic inequalities in overall and cause-specific stillbirth rates in England.DesignPopulation-based retrospective study.SettingEngland.ParticipantsStillbirths occurring among singleton infants born between 1 January 2000 and 31 December 2007.Main...

The risk factors for unexplained antepartum stillbirths in Scotland, 1994 to 2003

Objective:To determine the factors contributing to unexplained antepartum stillbirth in Scotland.Study Design:A 10-year birth database in Scotland was used to compare the unexplained antepartum stillbirth with other birth outcomes. The sample unit was a pregnant mother with a gestational age of 20 weeks and above and with a fetal birth weight of 200 g and above.Result:Maternal age of 35 years and above, lower deprivation category, inaccessible area of residence, maternal smoking, maternal height of <160 cm and gestational age of above 39 weeks were significantly associated with unexplained antepartum stillbirth. In multivariable analysis only maternal age (adjusted odds ratio (OR): 1.8, confidence interval (CI): 1.1 to 3.0, P=0.02), smoking during pregnancy (adjusted OR: 2.0, CI: 1.1 to 3.5, P=0.02), and maternal height (adjusted OR: 1.4, CI: 1.1 to 1.8, P=0.01), remain significant. Screening of pregnancies based on these three risk factors had 4.2% sensitivity and 99.4% specificity. The prevalence of stillbirth for this population was 0.2%. A positive predictive value of only 1.2% implies that only 1 in 83 women with these three risk factors will have antepartum stillbirth. The remaining 82 will suffer needless anxiety and potentially diagnostic procedures.Conclusion:Advanced maternal age, maternal smoking, and shorter maternal height were associated risk for unexplained antepartum stillbirth but screening based on these factors would be of limited value.

The Risk of Unexplained Antepartum Stillbirth in Second Pregnancies Following Caesarean Section in the First Pregnancy

Objective To determine if a previous caesarean section increases the risk of unexplained antepartum stillbirth in second pregnancies. Study design Retrospective cohort study. Setting Large Canadian perinatal database. Population 158 502 second births. Methods Data were obtained from a large perinatal database, which supplied data on demographics, pregnancy complications, maternal medical conditions, previous caesarean section and pregnancy outcomes. Main outcome measures Total and unexplained stillbirth. Results The antepartum stillbirth rate was 3.0/1000 in the previous caesarean section group compared with 2.7/1000 in the previous vaginal delivery group (P= 0.46). Multivariate logistic regression modelling, including terms for maternal age (polynomial), weight >91 kg, smoking during pregnancy, pre-pregnancy hypertension and diabetes, did not document an association between previous caesarean section and unexplained antepartum stillbirth (OR 1.27, 95% CI 0.92–1.77). Conclusion Caesarean section in the first birth does not increase the risk of unexplained antepartum stillbirth in second pregnancies.

The risk of unexplained antepartum stillbirth in second pregnancies following caesarean section in the first pregnancy

The risk of unexplained antepartum stillbirth in second pregnancies following caesarean section in the first pregnancy

The risk of unexplained antepartum stillbirth in second pregnancies following caesarean section in the first pregnancy

The risk of unexplained antepartum stillbirth in second pregnancies following caesarean section in the first pregnancy

Author response to: The risk of unexplained antepartum stillbirth in second pregnancies following caesarean section in the first pregnancy

Author response to: The risk of unexplained antepartum stillbirth in second pregnancies following caesarean section in the first pregnancy

The risk of unexplained antepartum stillbirth in second pregnancies following caesarean section in the first pregnancy

To determine if a previous caesarean section increases the risk of unexplained antepartum stillbirth in second pregnancies. Retrospective cohort study. Large Canadian perinatal database. 158 502 second births. Data were obtained from a large perinatal database, which supplied data on demographics, pregnancy complications, maternal medical conditions, previous caesarean section and pregnancy outcomes. Total and unexplained stillbirth. The antepartum stillbirth rate was 3.0/1000 in the previous caesarean section group compared with 2.7/1000 in the previous vaginal delivery group (P= 0.46). Multivariate logistic regression modelling, including terms for maternal age (polynomial), weight >91 kg, smoking during pregnancy, pre-pregnancy hypertension and diabetes, did not document an association between previous caesarean section and unexplained antepartum stillbirth (OR 1.27, 95% CI 0.92-1.77). Caesarean section in the first birth does not increase the risk of unexplained antepartum stillbirth in second pregnancies.

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Restricted fetal growth in sudden intrauterine unexplained death.

Unexplained antepartum stillbirth is a common cause of perinatal death, and identifying the fetus at risk is a challenge for obstetric practice. Intrauterine growth restriction (IUGR) is associated with a variety of adverse perinatal outcomes, but reports on its impact on unexplained stillbirths by population-based birthweight standards have been varying, including both unexplained and unexplored stillbirths. We have studied IUGR, assessed by individually adjusted fetal weight standards, in antepartum deaths that remained unexplained despite thorough postmortem investigations. Antenatal health cards from a complete population-based 10-year material of 76 validated sudden intrauterine unexplained deaths were compared to those of 582 randomly selected liveborn controls. Birthweight <10th percentile of the individualized standard adjusted for gestational age, maternal height, weight, parity, ethnicity, and fetal gender was defined as growth restriction. 52% of unexplained stillbirths were growth restricted, with a mean gestational age at death of 35.1 weeks. Suboptimal growth was the most important fetal determinant for sudden intrauterine unexplained death (odds ratio 7.0, 95% confidence interval 3.3-15.1). Concurrent maternal overweight or obesity, high age, and low education further increase the risk. Overweight and obesity increase the risk irrespective of fetal growth, and while high maternal age increases the risk of the normal weight fetus, it is not associated to growth restriction as a precursor of sudden intrauterine unexplained death. IUGR is an important risk factor of sudden intrauterine unexplained death, and this should be excluded in pregnancies with any other risk factor for sudden intrauterine unexplained death.

Caesarean section and risk of unexplained stillbirth in subsequent pregnancy.

Caesarean section is associated with an increased risk of disorders of placentation in subsequent pregnancies, but effects on the rate of antepartum stillbirth are unknown. We aimed to establish whether previous caesarean delivery is associated with an increased risk of antepartum stillbirth. We linked pregnancy discharge data from the Scottish Morbidity Record (1980-98) and the Scottish Stillbirth and Infant Death Enquiry (1985-98). We estimated the relative risk of antepartum stillbirth in second pregnancies using time-to-event analyses. For 120633 singleton second births, there were 68 antepartum stillbirths in 17754 women previously delivered by caesarean section (2.39 per 10000 women per week) and 244 in 102879 women previously delivered vaginally (1.44; p<0.001). Risk of unexplained stillbirth associated with previous caesarean delivery differed significantly with gestational age (p=0.04); the excess risk was apparent from 34 weeks (hazard ratio 2.23 [95% CI 1.48-3.36]). Risk was not attenuated by adjustment for maternal characteristics or outcome of the first pregnancy (2.74 [1.74-4.30]). The absolute risk of unexplained stillbirth at or after 39 weeks' gestation was 1.1 per 1000 women who had had a previous caesarean section and 0.5 per 1000 in those who had not. The difference was due mostly to an excess of unexplained stillbirths among women previously delivered by caesarean section. Delivery by caesarean section in the first pregnancy could increase the risk of unexplained stillbirth in the second. In women with one previous caesarean delivery, the risk of unexplained antepartum stillbirth at or after 39 weeks' gestation is about double the risk of stillbirth or neonatal death from intrapartum uterine rupture.

Comparative epidemiology of sudden infant death syndrome and sudden intrauterine unexplained death

Background: Unexplained antepartum stillbirth and sudden infant death syndrome (SIDS) are major contributors to perinatal and infant mortality in the western world. A relation between them has been suggested. As...