Association between stillbirth and risk factors known at pregnancy confirmation

Prediction of stillbirth: an umbrella review of evaluation of prognostic variables

BACKGROUND

Stillbirth accounts for over 2 million deaths a year worldwide and rates remains stubbornly high. Multivariable prediction models may be key to individualised monitoring, intervention or early birth in pregnancy to prevent stillbirth.

OBJECTIVES

To collate and evaluate systematic reviews of factors associated with stillbirth in order to identify variables relevant to prediction model development.

SEARCH STRATEGY

MEDLINE, Embase, DARE and Cochrane Library databases and reference lists were searched up to November 2019.

SELECTION CRITERIA

We included systematic reviews of association of individual variables with stillbirth without language restriction.

DATA COLLECTION AND ANALYSIS

Abstract screening and data extraction were conducted in duplicate. Methodological quality was assessed using AMSTAR and QUIPS criteria. The evidence supporting association with each variable was graded.

RESULTS

The search identified 1198 citations. Sixty-nine systematic reviews reporting 64 variables were included. The most frequently reported were maternal age (n = 5), body mass index (n = 6) and maternal diabetes (n = 5). Uterine artery Doppler appeared to have the best performance of any single test for stillbirth. The strongest evidence of association was for nulliparity and pre-existing hypertension.

CONCLUSION

We have identified variables relevant to the development of prediction models for stillbirth. Age, parity and prior adverse pregnancy outcomes had a more convincing association than the best performing tests, which were PAPP-A, PlGF and UtAD. The evidence was limited by high heterogeneity and lack of data on intervention bias.

TWEETABLE ABSTRACT

Review shows key predictors for use in developing models predicting stillbirth include age, prior pregnancy outcome and PAPP-A, PLGF and Uterine artery Doppler.

Findings in Stillbirths Associated with Placental Disease

OBJECTIVE

Placental disease is a leading cause of stillbirth. Our purpose was to characterize stillbirths associated with placental disease.

STUDY DESIGN

The Stillbirth Collaborative Research Network conducted a prospective, case-control study of stillbirths and live births from 2006 to 2008. This analysis includes 512 stillbirths with cause of death assignment and a comparison group of live births. We compared exposures between women with stillbirth due to placental disease and those due to other causes as well as between women with term (≥ 37 weeks) stillbirth due to placental disease and term live births.

RESULTS

A total of 121 (23.6%) out of 512 stillbirths had a probable or possible cause of death due to placental disease by Initial Causes of Fetal Death. Characteristics were similar between stillbirths due to placental disease and other stillbirths. When comparing term live births to stillbirths due to placental disease, women with non-Hispanic black race, Hispanic ethnicity, lack of insurance, or who were born outside of the United States had higher odds of stillbirth due to placental disease. Nulliparity and antenatal bleeding also increased risk of stillbirth due to placental disease.

CONCLUSION

Multiple discrete exposures were associated with stillbirth caused by placental disease. The relationship between these factors and utility of surveillance warrants further study.

Factors contributing to late stillbirth among women with pregnancy hypertension in a developing country

OBJECTIVE

To investigate the factors associated with late stillbirth among women with hypertensive disorders of pregnancy (HDP).

MATERIAL AND METHODS

The clinical details of women with HDP having late stillbirth were compared with controls having livebirth.

RESULTS

Total 208 cases and 288 controls were included in the study. Inadequate antenatal visits (p < 0.001, OR-5.92). birth weight < 2000 gms (p < 0.001, OR 10.3) and BW/PW ratio > 8 contributed significantly (p = 0.0001, OR-5.6) to stillbirth.

CONCLUSION

Poor antenatal care, birth weight below 2000gms and high BW/PW ratio was associated with a higher risk of stillbirth.

Obstetrics risk Assessment: Evaluation of selection criteria for vaccine research studies in pregnant women

Vaccines designed for use in pregnancy and vaccine trials specifically involving pregnant women are rapidly expanding. One of the key challenges in designing maternal immunization trials is that developing exclusion criteria requires understanding and quantifying the background risk for adverse pregnancy outcomes in the pregnancy being studied, which can occur independent of any intervention and be unrelated to vaccine administration. The Global Alignment of Immunization Safety Assessment in Pregnancy (GAIA) project has developed and published case definitions and guidelines for data collection, analysis, and evaluation of maternal immunization safety in trials involving pregnant women. Complementing this work, we sought to understand how to best assess obstetric risk of adverse outcomes and differentiate it from the assessment of vaccine safety. Quantification of obstetric risk is based on prior and current obstetric, and maternal medical history. We developed a step-wise approach to evaluate and quantify obstetric and maternal risk factors in pregnancy based on review of published literature and guidelines, and critically assessed these factors in the context of designing inclusion and exclusion criteria for maternal vaccine studies. We anticipate this risk assessment evaluation may assist clinical trialists with study design decisions, including selection of exclusion criteria for vaccine trials involving pregnant women, consideration of sub-group classification, such as high or low risk subjects, or schedule considerations, such as preferred trimester of gestation for an intervention during pregnancy. Additionally, this tool may be utilized in data stratification at time of study analyses.

Association Between Stillbirth at 23 Weeks of Gestation or Greater and Severe Maternal Morbidity

OBJECTIVE

To estimate whether stillbirth at 23 weeks of gestation or more is associated with increased risk of severe maternal morbidity compared with live birth, when stratified by maternal comorbidities.

METHODS

This retrospective cohort study used International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) diagnosis and procedure codes within the Healthcare Cost and Utilization Project's Florida State Inpatient Database. The first delivery of female Florida residents aged 13-54 years old from 2005 to 2014 was included. The exposure was an ICD-9-CM code of stillbirth at 23 weeks of gestation or more; the control was an ICD-9-CM code of singleton live birth. Deliveries were stratified by the presence of 1 or more conditions within a well-validated maternal morbidity composite using ICD-9-CM codes during delivery hospitalization. The primary outcome was an ICD-9-CM diagnosis or procedure code during delivery hospitalization of any indices within the Centers for Disease Control and Prevention's severe maternal morbidity composite. Multivariable analyses adjusted for maternal sociodemographic factors and delivery mode to compare outcomes after stillbirth with live-birth delivery.

RESULTS

Nine thousand five hundred twenty-three women who delivered stillborn fetuses and 1,353,044 with liveborn neonates were included. Among 6,590 stillbirths and 935,913 live births without maternal comorbidities, severe maternal morbidity was significantly more common during stillbirth delivery (n=345 [5.2%]), corresponding to a seven-fold increased risk compared with live birth (n=8,318 [0.9]; adjusted odds ratio [aOR] 7.05 [95% CI 6.27-7.93]). Among 2,933 stillbirths and 417,131 live births with maternal comorbidities, severe maternal morbidity was significantly more common during stillbirth delivery (n=390 [13.3%]): the risk was more than six-fold higher comparatively (n=11,122 [2.7%]; aOR 6.21 [95% CI 5.54-6.96]). Most maternal comorbidities were individually associated with higher risk of severe maternal morbidity during stillbirth compared with live-birth delivery.

CONCLUSION

Though severe maternal morbidity is overall uncommon, delivering a stillborn fetus 23 weeks of gestation or greater is associated with increased likelihood of severe maternal morbidity, particularly among women with comorbidities, suggesting health care providers must be vigilant about severe maternal morbidity during stillbirth delivery.

Understanding high rates of stillbirth and neonatal death in a disadvantaged, high-migrant district in France: A perinatal audit

INTRODUCTION

The objective of this study is to investigate factors associated with risks of perinatal death in a disadvantaged, high-migrant French district with mortality rates above the national average.

MATERIAL AND METHODS

The study design is a perinatal audit in 2014 in all 11 maternity units in the Seine-Saint-Denis district (25 037 births). The data come from medical chart abstraction, maternal interviews and peer assessor confidential review of deaths. A representative sample of live births in the same district, from the 2010 French Perinatal Survey, was used for comparisons (n = 429). The main outcome measures were stillbirth and neonatal death (0-27 days) at ≥22 weeks of gestation.

RESULTS

The audit included 218 women and 227 deaths (156 stillbirths, 71 neonatal deaths); 75 women were interviewed. In addition to primiparity and multiple pregnancy, overweight and obesity increased mortality risks (50% of cases, adjusted odds ratios [aOR] 1.7, 95% confidence interval [CI] 1.1-2.8, and aOR 1.9 [95% CI 1.1-3.2], respectively) as did the presence of preexisting medical/obstetric conditions (28.6% of cases, aOR 3.2, 95% CI 2.0-5.3). Problems accessing or complying with care were noted in 25% of medical records and recounted in 50% of interviews. Assessors identified suboptimal factors in 73.2% of deaths and judged 33.9% to be possibly or probably preventable. Care not adapted to risk factors and poor healthcare coordination were frequent suboptimal factors. Possibly preventable deaths were higher (P < .05) for women with gestational diabetes or hypertension (44.6%) than women without (29.0%).

CONCLUSIONS

Preventive actions to improve healthcare referral and coordination, especially for overweight and obese women and women with medical and obstetrical risk factors, could reduce perinatal mortality in disadvantaged areas.

When the Fetus Goes Still and the Birth Is Tragic: The Role of the Placenta in Stillbirths

Because of the critical role that placental structure and function plays during pregnancy, abnormal placental structure and function is closely related to stillbirth: when an infant dies before birth. However, understanding the role of the placental and specific lesions is incomplete, in part because of the variation in definitions of lesions and in classifying causes of stillbirths. Nevertheless, placental abnormalities are seen more frequently in stillbirths than live births, with placental abruption, chorioamnionitis, and maternal vascular malperfusion most commonly reported. Critically, some placental lesions affect the management of subsequent pregnancies. Histopathological examination of the placenta is recommended following stillbirth.

Stillbirth Associated With Infection in a Diverse U.S. Cohort

OBJECTIVE

To better characterize infection-related stillbirth in terms of pathogenesis and microbiology.

METHODS

We conducted a secondary analysis of 512 stillbirths in a prospective, multisite, geographically, racially and ethnically diverse, population-based study of stillbirth in the United States. Cases underwent evaluation that included maternal interview, chart abstraction, biospecimen collection, fetal autopsy, and placental pathology. Recommended evaluations included syphilis and parvovirus serology. Each case was assigned probable and possible causes of death using the INCODE Stillbirth Classification System. Cases where infection was assigned as a probable or possible cause of death were reviewed. For these cases, clinical scenario, autopsy, maternal serology, culture results, and placental pathology were evaluated.

RESULTS

For 66 (12.9%) cases of stillbirth, infection was identified as a probable or possible cause of death. Of these, 36% (95% CI 35-38%) were categorized as a probable and 64% (95% CI 62-65%) as a possible cause of death. Infection-related stillbirth occurred earlier than non-infection-related stillbirth (median gestational age 22 vs 28 weeks, P=.001). Fetal bacterial culture results were available in 47 cases (71%), of which 35 (53%) grew identifiable organisms. The predominant species were Escherichia coli (19, 29%), group B streptococcus (GBS) (8, 12%), and enterococcus species (8, 12%). Placental pathology revealed chorioamnionitis in 50 (76%), funisitis in 27 (41%), villitis in 11 (17%), deciduitis in 35 (53%), necrosis in 27 (41%), and viral staining in seven (11%) cases. Placental pathology found inflammation or evidence of infection in 65 (99%) cases and fetal autopsy in 26 (39%) cases. In infection-related stillbirth cases, the likely causative nonbacterial organisms identified were parvovirus in two (3%) cases, syphilis in one (2%) case, cytomegalovirus (CMV) in five (8%) cases, and herpes in one (2%) case.

CONCLUSION

Of infection-related stillbirth cases in a large U.S. cohort, E coli, GBS, and enterococcus species were the most common bacterial pathogens and CMV the most common viral pathogen.

The association between gestational weight gain z-score and stillbirth: a case-control study

BACKGROUND

There is limited information on potentially modifiable risk factors for stillbirth, such as gestational weight gain (GWG). Our purpose was to explore the association between GWG and stillbirth using the GWG z-score.

METHODS

We analyzed 479 stillbirths and 1601 live births from the Stillbirth Collaborative Research Network case-control study. Women with triplets or monochorionic twins were excluded from analysis. We evaluated the association between GWG z-score (modeled as a restricted cubic spline with knots at the 5th, 50th, and 95th percentiles) and stillbirth using multivariable logistic regression with generalized estimating equations, adjusting for pre - pregnancy body mass index (BMI) and other confounders. In addition, we conducted analyses stratified by pre - pregnancy BMI category (normal weight, overweight, obese).

RESULTS

Mean GWG was 18.95 (SD 17.6) lb. among mothers of stillbirths and 30.89 (SD 13.3) lb. among mothers of live births; mean GWG z-score was - 0.39 (SD 1.5) among mothers of cases and - 0.17 (SD 0.9) among control mothers. In adjusted analyses, the odds of stillbirth were elevated for women with very low GWG z-scores (e.g., adjusted odds ratio (aOR) and 95% Confidence Interval (CI) for z-score - 1.5 SD versus 0 SD: 1.52 (1.30, 1.78); aOR (95% CI) for z-score - 2.5 SD versus 0 SD: 2.36 (1.74, 3.20)). Results differed slightly by pre - pregnancy BMI. The odds of stillbirth were slightly elevated among women with overweight BMI and GWG z-scores ≥1 SD (e.g., aOR (95% CI) for z-score of 1.5 SD versus 0 SD: 1.84 (0.97, 3.50)).

CONCLUSIONS

GWG z-scores below - 1.5 SD are associated with increased odds of stillbirth.

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

OBJECTIVE

To 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.

DESIGN

Retrospective cohort study.

SETTING

England, Wales, Scotland and the UK Crown Dependencies.

PARTICIPANTS

All singleton births between 1 January 2014 and 31 December 2015 at ≥24 weeks' gestation.

MAIN OUTCOME MEASURE

Cause-specific stillbirth or neonatal death (0-27 days after birth) per 10 000 births by deprivation quintile.

RESULTS

Data on 5694 stillbirths (38.1 per 10 000 total births) and 2368 neonatal deaths (15.9 per 10 000 live births) were obtained from Mothers and Babies: Reducing Risk through Audits and Confidential Enquiries across the UK (MBRRACE-UK). Women from the most deprived areas were 1.68 (95% CI 1.56 to 1.81) times more likely to experience a stillbirth and 1.67 (95% CI 1.48 to 1.87) times more likely to experience a neonatal death than those from the least deprived areas, equating to an excess of 690 stillbirths and 231 neonatal deaths per year associated with deprivation. Small for gestational age (SGA) unexplained antepartum stillbirth was the greatest contributor to excess stillbirths accounting for 33% of the deprivation gap in stillbirths. Congenital anomalies accounted for the majority (59%) of the deprivation gap in neonatal deaths, followed by preterm birth not SGA (24-27 weeks, 27%).

CONCLUSIONS

Cause-specific mortality rates at a national level allow identification of key areas of focus for future intervention strategies to reduce mortality. Despite a reduction in the deprivation gap for stillbirths and neonatal deaths, public health interventions should primarily focus on socioeconomic determinants of SGA stillbirth and congenital anomalies.

Association of late second trimester miscarriages with placental histology and autopsy findings

OBJECTIVES

To describe the placental histology and autopsy findings in pregnancies where fetal demise occurred before a gestational age of 22 weeks.

STUDY DESIGN

This study was a subset of a larger study where the effect of alcohol exposure during pregnancy on stillbirths was studied. In a prospective cohort, 7,010 singleton pregnancies were followed from the first antenatal visit until infant one year of age visit. Gestational age was assessed by ultrasound, preferably at the first antenatal visit. All pregnancy losses were identified and when the fetuses delivered at or after a gestation of 20 weeks, the mother or parents were approached for consent for autopsy. This study describes the placental pathology and findings at autopsy in losses before 22 weeks gestation (late second trimester miscarriages).

RESULTS

Fourteen cases were identified in which 13 had an autopsy and 12 had a histological examination of the placenta. The most prevalent histological abnormality was placental abruption which was seen in 6 miscarriages, occasionally on its own, or in combination with maternal vascular malperfusion or acute chorioamnionitis. The second most frequent finding was maternal vascular malperfusion, as found in five placentas, alone or in combination with other pathology. The third most frequent pathology was acute chorioamnionitis, found in four placentas, in combination or alone. Other causes were diffuse chronic villitis due to cytomegalovirus infection and early amnion rupture with anhydramnios and cord obstruction.

CONCLUSIONS

Causes of fetal demise at the end of the second trimester differ little from causes of stillbirth. There is value in using placental histology in late second trimester miscarriages to try to identify the cause of demise.

Learning from experience: cellular and molecular bases for improved outcome in subsequent pregnancies

The frequencies of preeclampsia, fetal growth restriction, fetal demise, and low birthweight are lower in subsequent pregnancies. Enhanced maternal cardiovascular adaptation, shorter first and second stages of labor, and more robust lactation also have been observed in subsequent as compared with first pregnancies. We sought to investigate the cellular and molecular bases for better outcomes in subsequent pregnancies. Based on the knowledge that specialized immune cells at the maternal-fetal interface, decidual natural killer cells, promote development of the placental bed and conversion of the spiral arteries by secreting a myriad of angiogenic and growth factors, we asked whether decidual natural killer cells differ in subsequent as compared with first pregnancies. This idea stemmed from recent studies suggesting that natural killer cells, although part of the innate immune system, possess some features of adaptive immunity, including a certain type of immune cell memory, termed trained immunity. We found that decidual natural killer cells from parous women "remember pregnancy" and differ from decidual natural killer cells of primigravidae. Compared with the decidual natural killer cells of first pregnancy, these cells, that we termed pregnancy-trained decidual natural killer cells, express greater levels of the natural killer receptors NKG2C and leukocyte immunoglobulin-like receptor B1, which interact with ligands expressed on invasive trophoblasts. Furthermore, they secrete greater levels of several growth factors, including vascular endothelial growth factor α as well as interferon-γ, augmenting remodeling of the placental bed. We propose that this pregnancy-trained memory dwells in the epigenome, where memory of stimuli is known to persist even when the stimulus is no longer present. This epigenetic memory apparently resides in endometrial natural killer cells between pregnancies. We suggest that this trained memory, which we coined pregnancy-trained decidual natural killer cells, may be the missing link in the immune basis for enhanced subsequent pregnancy. Epigenetic memory (chromatin modification) also may afford a global explanation for additional findings of enhanced maternal cardiovascular adaptation, shorter first and second stages of labor, and more robust lactation. Understanding the molecular and cellular bases of improved outcomes of subsequent pregnancy may lead to the development of treatment modalities designed for women at high risk for pregnancy disorders originating at the maternal-fetal interface.

Maternal Risk Factors for Stillbirth: A Registry-Based Study

Background and Objectives: The number of stillbirths has reduced more slowly than has maternal mortality or mortality in children younger than 5 years, which were explicitly targeted in the Millennium Development Goals. Placental pathologies and infection associated with preterm birth are linked to a substantial proportion of stillbirths. Appropriate preconception care and quality antenatal care that is accessible to all women has the potential to reduce stillbirth rates. The aim of the present study was to assess potential risk factors associated with stillbirth within maternal medical diseases and obstetric complications. Materials and Methods: Retrospective cohort study (2001-2014) was used to analyse data from the Medical Birth Register on stillbirth and live births as controls. Adjusted Odds ratios (aOR) with 95% confidence intervals (CI) were estimated. Multiple regression model adjusted for maternal age, parity and gestational age. Results: The stillbirth rate was 6.2 per 1000 live and stillbirths. The presence of maternal medical diseases greatly increased the risk of stillbirth including diabetes mellitus (aOR = 2.5; p < 0.001), chronic hypertension 3.1 (aOR = 3.1; p < 0.001) and oligohydromnios/polyhydromnios (aOR = 2.4; p < 0.001). Pregnancy complications such as intrauterine growth restriction (aOR = 2.2; p < 0.001) was important risk factor for stillbirth. Abruption was associated with a 2.8 odds of stillbirth. Conclusions: Risk factors most significantly associated with stillbirth include maternal history of chronic hypertension and abruptio placenta which is a common cause of death in stillbirth. Early identification of potential risk factors and appropriate perinatal management are important issues in the prevention of adverse fetal outcomes and preventive strategies need to focus on improving antenatal detection of fetal growth restriction.

Risks of stillbirth and neonatal death with advancing gestation at term: A systematic review and meta-analysis of cohort studies of 15 million pregnancies

BACKGROUND

Despite advances in healthcare, stillbirth rates remain relatively unchanged. We conducted a systematic review to quantify the risks of stillbirth and neonatal death at term (from 37 weeks gestation) according to gestational age.

METHODS AND FINDINGS

We searched the major electronic databases Medline, Embase, and Google Scholar (January 1990-October 2018) without language restrictions. We included cohort studies on term pregnancies that provided estimates of stillbirths or neonatal deaths by gestation week. We estimated the additional weekly risk of stillbirth in term pregnancies that continued versus delivered at various gestational ages. We compared week-specific neonatal mortality rates by gestational age at delivery. We used mixed-effects logistic regression models with random intercepts, and computed risk ratios (RRs), odds ratios (ORs), and 95% confidence intervals (CIs). Thirteen studies (15 million pregnancies, 17,830 stillbirths) were included. All studies were from high-income countries. Four studies provided the risks of stillbirth in mothers of White and Black race, 2 in mothers of White and Asian race, 5 in mothers of White race only, and 2 in mothers of Black race only. The prospective risk of stillbirth increased with gestational age from 0.11 per 1,000 pregnancies at 37 weeks (95% CI 0.07 to 0.15) to 3.18 per 1,000 at 42 weeks (95% CI 1.84 to 4.35). Neonatal mortality increased when pregnancies continued beyond 41 weeks; the risk increased significantly for deliveries at 42 versus 41 weeks gestation (RR 1.87, 95% CI 1.07 to 2.86, p = 0.012). One additional stillbirth occurred for every 1,449 (95% CI 1,237 to 1,747) pregnancies that advanced from 40 to 41 weeks. Limitations include variations in the definition of low-risk pregnancy, the wide time span of the studies, the use of registry-based data, and potential confounders affecting the outcome.

CONCLUSIONS

Our findings suggest there is a significant additional risk of stillbirth, with no corresponding reduction in neonatal mortality, when term pregnancies continue to 41 weeks compared to delivery at 40 weeks.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42015013785.

Risk factors of stillbirth among mothers delivered in public hospitals of Central Zone, Tigray, Ethiopia

BACKGROUND

Stillbirth is a death before the complete expulsion or extraction from the mother. The burden is severe and high in developing countries. Risk factors for stillbirth are not yet studied in Ethiopia.

OBJECTIVE

To identify risk factors of stillbirth among mothers delivered in public hospitals of Central Zone Tigray, Ethiopia.

METHODS

A case-control study design was used. Data collection period was from January to April 2018. Study subjects 63 cases and 252 controls were selected using systematic random sampling technique from respective hospitals. The interviewer-administered questionnaire, observational, and chart analysis were used to collect the data. A binary logistic regression model was employed. Results were presented at significance level P-value <0.05.

RESULTS

Maternal hypertension [AOR=12.83; 95% CI 3.38, 48.83], low birth weight [AOR=5.6; 95% CI 2.39, 13.38], pre-term [AOR=2.6;95%CI 1.12,6.16], alcohol intake [AOR=7.56; 95% CI 1.68, 34.04], polyhydramnios [AOR=13.43; 95% CI 3.63, 49.67], and meconium stained amniotic fluid [AOR=7.88; 95% CI 1.73, 8.18] were risk factors of stillbirth.

CONCLUSION

The risk of stillbirth is increased with increasing maternal complication like maternal hypertension, alcohol consumption, polyhydramnios, and meconium-stained amniotic fluid. The occurrence of preterm and low birth weight of the fetus had an effect on the risk of stillbirth.

Interpregnancy interval and risk of stillbirth: a population-based case control study

PURPOSE

We examined the association between interpregnancy intervals (IPIs) and stillbirth (defined as fetal death ≥20 weeks), as both short and long IPIs have been associated with adverse perinatal outcomes. Prior pregnancy loss is also a known risk factor for stillbirth, and women who suffer a prior loss often have shorter IPIs. For these reasons, we also sought to quantify the proportion of the association between prior pregnancy loss and subsequent stillbirth risk that may be attributed to a short IPI.

METHODS

We used data from the Stillbirth Collaborative Research Network, a multisite case-control study conducted in 2006-2008, restricted to singleton pregnancies among multiparous or multigravid women (985 controls and 291 cases). We accounted for complex sample design and nonparticipation with weighted multivariable logistic regression.

RESULTS

In the adjusted models, IPIs <6 months, as compared with a reference of 18-23 months, were associated with increased odds of stillbirth (aOR 1.6, 95% CI: 0.8, 3.4). Long IPIs (60-100 months) were also associated with an increased odds of stillbirth (aOR 2.4, 95% CI: 1.2, 4.5). After control for covariates, about one-fifth (21.2%) of the association of prior pregnancy loss (stillbirth, ectopic pregnancy, molar pregnancy, or spontaneous abortion) and stillbirth may be attributable to a short IPI.

CONCLUSIONS

Our results suggest that women who experience a prior pregnancy loss may benefit from additional counseling on adequate birth spacing to reduce subsequent stillbirth risk.

Racial and ethnic disparities in birth outcomes and labour and delivery-related charges among women with intellectual and developmental disabilities

BACKGROUND

Women with intellectual and developmental disabilities (IDD) in the USA are bearing children at increasing rates. However, very little is known whether racial and ethnic disparities in birth outcomes and labour and delivery-related charges exist in this population. This study investigated racial and ethnic disparities in birth outcomes and labour and delivery-related charges among women with IDD.

METHODS

The study employed secondary analysis of the 2004-2011 Healthcare Cost and Utilization Project National Inpatient Sample, the largest all-payer, publicly available US inpatient healthcare database. Hierarchical mixed-effect logistic and linear regression models were used to compare the study outcomes.

RESULTS

We identified 2110 delivery-associated hospitalisations among women with IDD including 1275 among non-Hispanic White women, 527 among non-Hispanic Black women and 308 among Hispanic women. We found significant disparities in stillbirth among non-Hispanic Black and Hispanic women with IDD compared with their non-Hispanic White peers [odds ratio = 2.50, 95% confidence interval (CI): 1.16-5.28, P < 0.01 and odds ratio = 2.53, 95% CI: 1.08-5.92, P < 0.01, respectively]. There were no racial and ethnic disparities in caesarean delivery, preterm birth and small-for-gestational-age neonates among women with IDD. The average labour and delivery-related charges for non-Hispanic Black and Hispanic Women with IDD ($18 889 and $22 481, respectively) exceeded those for non-Hispanic White women with IDD ($14 886) by $4003 and $7595 or by 27% and 51%, respectively. The significant racial and ethnic differences in charges persisted even after controlling for a range of individual-level and institutional-level characteristics and were 6% (ln(β) = 0.06, 95% CI: 0.01-0.11, P < 0.05) and 9% (ln(β) = 0.09, 95% CI: 0.03-0.14, P < 0.01) higher for non-Hispanic Black and Hispanic Women with IDD compared with non-Hispanic White women with IDD.

CONCLUSIONS

Our findings highlight the need for an integrated approach to the delivery of comprehensive perinatal services for racial and ethnic minority women with IDD to reduce their risk of having a stillbirth. Additionally, further research is needed to examine the causes of racial and ethnic disparities in hospital charges for labour and delivery admission among women with IDD and ascertain whether price discrimination exists based on patients' racial or ethnic identities.

Is it possible to predict late antepartum stillbirth by means of cerebroplacental ratio and maternal characteristics?

Objective: To examine the potential value of fetal ultrasound and maternal characteristics in the prediction of antepartum stillbirth after 32 weeks' gestation.Methods: This was a retrospective multicenter study in Spain. In 29 pregnancies, umbilical artery pulsatility index (UA PI), middle cerebral artery pulsatility index (MCA PI), cerebroplacental ratio (CPR), estimated fetal weight (EFW), and maternal characteristics were recorded within 15 days prior to a stillbirth. The values of UA PI, MCA PI, and CPR were converted into multiples of the normal median (MoM) for gestational age and the EFW was expressed as percentile according to a Spanish reference range for gestational age. Data from the 29 pregnancies with stillbirths and 2298 control pregnancies resulting in livebirths were compared and multivariate logistic regression analysis was used to determine significant predictors of stillbirth.Results: The only significant predictor of stillbirth was CPR (OR = 0.161, 95% confidence interval [CI] 0.035, 0.654; p = .014); the area under the receiver operating characteristics curve was 0.663 (95% CI 0.545, 0.782) and the detection rate (DR) was 32.14% at a 10% false-positive rate (FPR). In addition, when we included MCA and UA PI MoM instead of CPR, only MCA PI MoM was significant (OR = 0.104, 95% confidence interval [CI] 0.013, 0.735; p = .029), with similar prediction abilities (area under the curve (AUC) 0.645, DR 28.6%, FPR 10%).Conclusions: The CPR and MCA PI are predictors of late stillbirth but the performance of prediction is poor.

Investigating Mechanisms of Stillbirth in the Setting of Prenatal Substance Use

Introduction

Intrauterine fetal demise affects between 0.4-0.8% of pregnancies worldwide. This significant adverse pregnancy outcome continues to be poorly understood. In utero exposure to substances increases the risk of stillbirth to varying degrees according to the type of substance and degree of exposure. The aim of this qualitative narrative review is to investigate common biologic relationships between stillbirth and maternal substance use.

Methods

A PubMed literature search was conducted to query the most commonly used substances and biologic mechanisms of stillbirth. Search terms included "stillbirth," "intrauterine fetal demise," "placenta," "cocaine," "tobacco," "alcohol," "methamphetamines," "opioids/ opiates," and "cannabis."

Results

There are very few studies identifying a direct link between substance use and stillbirth. Several studies demonstrate associations with placental lesions of insufficiency including poor invasion, vasoconstriction, and sequestration of toxic substances that inhibit nutrient transport. Restricted fetal growth is the most common finding in pregnancies complicated by all types of substance use.

Discussion

More research is needed to understand the biologic mechanisms of stillbirth. Such knowledge will be foundational to understanding how to prevent and treat the adverse effects of substances during pregnancy.

Does the Use of Diagnostic Technology Reduce Fetal Mortality?

OBJECTIVE

To examine the effect that the introduction of new diagnostic technology in obstetric care has had on fetal death.

DATA SOURCE

The Medical Birth Registry of Norway provided detailed medical information for approximately 1.2 million deliveries from 1967 to 1995. Information about diagnostic technology was collected directly from the maternity units, using a questionnaire.

STUDY DESIGN

The data were analyzed using a hospital fixed-effects regression with fetal mortality as the outcome measure. The key independent variables were the introduction of ultrasound and electronic fetal monitoring at each maternity ward. Hospital-specific trends and risk factors of the mother were included as control variables. The richness of the data allowed us to perform several robustness tests.

PRINCIPAL FINDING

The introduction of ultrasound caused a significant drop in fetal mortality rate, while the introduction of electronic fetal monitoring had no effect on the rate. In the population as a whole, ultrasound contributed to a reduction in fetal deaths of nearly 20 percent. For post-term deliveries, the reduction was well over 50 percent.

CONCLUSION

The introduction of ultrasound made a major contribution to the decline in fetal mortality at the end of the last century.

Screening and management of the small for gestational age fetus in the UK: A survey of practice

BACKGROUND

Antenatal detection of the small for gestational (SGA) fetus has become an important indicator of quality of antenatal care in the UK. This has been driven by a desire to reduce stillbirth in this at risk group.

METHODS

We conducted a postal survey of 187 NHS consultant units within the UK to determine what the current practice for the detection and subsequent management of the suspected SGA fetus was following the guidance from the Royal College of Obstetricians and Gynaecologists (RCOG) in 2013.

RESULTS

The survey was performed in 3 rounds between 2016 and 2017 with a response rate of 65%. 85% of units assessed risk factors for SGA at booking. 81% of units used a customized symphysis fundal height (SFH) chart to screen for SGA with 95% of them using a cut off of <10th centile to refer for ultrasound assessment. When ultrasound is used to detect SGA, 80% of units used estimated fetal weight (EFW), with 89% of these using a cut off of <10th centile to diagnose SGA. Umbilical artery (UA) Doppler monitoring was undertaken in 97% of management and 94% delivered after 37 weeks. Only 24% of units had a dedicated fetal growth clinic, whilst 48% of units were able to offer computerised CTG to monitor the SGA fetus.

CONCLUSIONS

Overall there is consistency in the screening methods for SGA (customised SFH charts) and identification of suspected SGA (SFH <10th centile, EFW <10th centile, UA monitoring and induction of labour at term). There was a low uptake of computerized CTG to monitor SGA babies and a low number of specialised fetal growth clinics.

Optimal Obstetric Management for Women with Diabetes: the Benefits and Costs of Fetal Surveillance

PURPOSE OF REVIEW

To elaborate on the risks and benefits associated with antenatal fetal surveillance for stillbirth prevention in women with diabetes.

RECENT FINDINGS

Women with pregestational diabetes have a 3- to 5-fold increased odds of stillbirth compared to women without diabetes. The stillbirth risk in women with gestational diabetes (GDM) is more controversial; while recent data suggest the odds for stillbirth are approximately 50% higher in women with GDM at term (37 weeks and beyond) than in those without GDM, it is unclear if this risk is seen in women with optimal glycemic control. Current professional society guidelines are broad with respect to fetal testing strategies and delivery timing in women with diabetes. The data supporting strategies to reduce the risk of stillbirth in women with diabetes are limited. Antepartum fetal surveillance should be performed to reduce stillbirth rates; however, the optimal test, frequency of testing, and delivery timing are not yet clear. Future studies of obstetric management for women with diabetes should consider not just individual but also system level costs and benefits associated with antenatal surveillance.

Stillbirth, Inflammatory Markers, and Obesity: Results from the Stillbirth Collaborative Research Network

BACKGROUND

Obesity is associated with increased risk of stillbirth, although the mechanisms are unknown. Obesity is also associated with inflammation. Serum ferritin, C-reactive protein, white blood cell count, and histologic chorioamnionitis are all markers of inflammation.

OBJECTIVE

This article determines if inflammatory markers are associated with stillbirth and body mass index (BMI). Additionally, we determined whether inflammatory markers help to explain the known relationship between obesity and stillbirth.

STUDY DESIGN

White blood cell count was assessed at admission to labor and delivery, maternal serum for assessment of various biomarkers was collected after study enrollment, and histologic chorioamnionitis was based on placental histology. These markers were compared for stillbirths and live births overall and within categories of BMI using analysis of variance on logarithmic-transformed markers and logistic regression for dichotomous variables. The impact of inflammatory markers on the association of BMI categories with stillbirth status was assessed using crude and adjusted odds ratios (COR and AOR, respectively) from logistic regression models. The interaction of inflammatory markers and BMI categories on stillbirth status was also assessed through logistic regression. Additional logistic regression models were used to determine if the association of maternal serum ferritin with stillbirth is different for preterm versus term births. Analyses were weighted for the overall population from which this sample was derived.

RESULTS

A total of 497 women with singleton stillbirths and 1,414 women with live births were studied with prepregnancy BMI (kg/m²) categorized as normal (18.5-24.9), overweight (25.0-29.9), or obese (30.0 + ). Overweight (COR, 1.48; 95% confidence interval [CI]: 1.14-1.94) and obese women (COR, 1.60; 95% CI: 1.23-2.08) were more likely than normal weight women to experience stillbirth. Serum ferritin levels were higher (geometric mean: 37.4 ng/mL vs. 23.3, p < 0.0001) and C-reactive protein levels lower (geometric mean: 2.9 mg/dL vs. 3.3, p = 0.0279), among women with stillbirth compared with live birth. Elevated white blood cell count (15.0 uL × 10³ or greater) was associated with stillbirth (21.2% SB vs. 10.0% live birth, p < 0.0001). Histologic chorioamnionitis was more common (33.2% vs. 15.7%, p < 0.0001) among women with stillbirth compared with those with live birth. Serum ferritin, C-reactive protein, and chorioamnionitis had little impact on the ORs associating stillbirth with overweight or obesity. Adjustment for elevated white blood cell count did not meaningfully change the OR for stillbirth in overweight versus normal weight women. However, the stillbirth OR for obese versus normal BMI changed by more than 10% when adjusting for histologic chorioamnionitis (AOR, 1.38; 95% CI: 1.02-1.88), indicating confounding. BMI by inflammatory marker interaction terms were not significant. The association of serum ferritin levels with stillbirth was stronger among preterm births (p = 0.0066).

CONCLUSION

Maternal serum ferritin levels, elevated white blood cell count, and histologic chorioamnionitis were positively and C-reactive protein levels negatively associated with stillbirth. Elevated BMIs, both overweight and obese, were associated with stillbirth when compared with women with normal BMI. None of the inflammatory markers fully accounted for the relationship between obesity and stillbirth. The association of maternal serum ferritin with stillbirth was stronger in preterm than term stillbirths.

Context for implementing a gestational weight gain program nationally

OBJECTIVES

Use the Consolidated Framework for Implementation Research to describe the context in which a gestational weight gain (GWG) intervention, embedded within Parents as Teachers (PAT), will be implemented at PAT sites nationwide.

METHODS

Ten site leaders and six parent educators from ten PAT sites in eight states participated in semi-structured interviews and a survey. Audio-recordings and systematic notes were used in a deductive analysis. Scales were descriptively analyzed.

RESULTS

Surveys demonstrated positive perspectives of PAT+GWG. In interviews, participants described PAT+GWG filling a need for prenatal health education and confidence delivering this content, valued integration of PAT+GWG within the PAT curriculum, and recommended materials to meet their clients' needs.

CONCLUSIONS

Contextual information can help maximize PAT+GWG's impact.

Smith-Lemli-Opitz Mutations in Unexplained Stillbirths

OBJECTIVE

Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive syndrome caused by a defect in cholesterol biosynthesis with mutations in 7-dehydrocholesterol reductase (DHCR7). A total of 3% of Caucasians carry DHCR7 mutations, theoretically resulting in a homozygote frequency of 1/4000. However, SLOS occurs in only 1/20,000 to 60,000 live births. Our objective was to assess DHCR7 mutations in unexplained stillbirths.

STUDY DESIGN

Prospective, multicenter, population-based case-control study of all stillbirths and a representative sample of live births enrolled in five geographic areas. Cases with stillbirth due to obstetric complications, infection, or aneuploidy, and those with poor quality deoxyribonucleic acid (DNA) were excluded. DNA was extracted from placental tissue stored at -80°C, and exons 3 to 9 of the DCHR7 gene were amplified, purified, and subjected to bidirectional sequencing to identify mutations.

RESULTS

One-hundred forty four stillbirths were unexplained and had adequate DNA for analysis. Nine stillbirths of 139 (6.5%) had a single mutation in one allele in coding exons 3 to 9 of DHCR7 (Table 1). One case (0.7%) was a compound heterozygote for mutations in exons 3 to 9 of DHCR7; this fetus had no clinical or histologic features of SLOS.

CONCLUSION

We detected SLOS mutations in only 0.7% of stillbirths. This does not support a strong association between unrecognized DHCR7 mutations and stillbirth.

Selection in utero and population health: Theory and typology of research

Public health researchers may assume, based on the fetal origins literature, that "scarring" of birth cohorts describes the population response to modern-day stressors. We contend, based on extensive literature concerned with selection in utero, that this assumption remains questionable. At least a third and likely many more of human conceptions fail to yield a live birth. Those that survive to birth, moreover, do not represent their conception cohort. Increasing data availability has led to an improved understanding of selection in utero and its implications for population health. The literature describing selection in utero, however, receives relatively little attention from social scientists. We aim to draw attention to the rich theoretical and empirical literature on selection in utero by offering a typology that organizes this diverse work along dimensions we think important, if not familiar, to those studying population health. We further use the typology to identify important gaps in the literature. This work should interest social scientists for two reasons. First, phenomena of broad scholarly interest (i.e., social connectivity, bereavement) affect the extent and timing of selection in utero. Second, the life-course health of a cohort depends in part on the strength of such selection. We conclude by identifying new research directions and with a reconciliation of the apparent contradiction between the "fetal origins" literature and that describing selection in utero.

Association of participation in a supplemental nutrition program with stillbirth by race, ethnicity, and maternal characteristics

BACKGROUND

Participation in the Special Supplemental Nutrition Program for Women, Infants and Children (WIC) has been associated with lower risk of stillbirth. We hypothesized that such an association would differ by race/ethnicity because of factors associated with WIC participation that confound the association.

METHODS

We conducted a secondary analysis of the Stillbirth Collaborative Research Network's population-based case-control study of stillbirths and live-born controls, enrolled at delivery between March 2006 and September 2008. Weighting accounted for study design and differential consent. Five nested models using multivariable logistic regression examined whether the WIC participation/stillbirth associations were attenuated after sequential adjustment for sociodemographic, health, healthcare, socioeconomic, and behavioral factors. Models also included an interaction term for race/ethnicity x WIC.

RESULTS

In the final model, WIC participation was associated with lower adjusted odds (aOR) of stillbirth among non-Hispanic Black women (aOR: 0.34; 95% CI 0.16, 0.72) but not among non-Hispanic White (aOR: 1.69; 95% CI: 0.89, 3.20) or Hispanic women (aOR: 0.91; 95% CI 0.52, 1.52).

CONCLUSIONS

Contrary to our hypotheses, control for potential confounding factors did not explain disparate findings by race/ethnicity. Rather, WIC may be most beneficial to women with the greatest risk factors for stillbirth. WIC-eligible, higher-risk women who do not participate may be missing the potential health associated benefits afforded by WIC.

Trends and determinants of stillbirth in developing countries: results from the Global Network's Population-Based Birth Registry

Background

Stillbirth rates remain high, especially in low and middle-income countries, where rates are 25 per 1000, ten-fold higher than in high-income countries. The United Nations’ Every Newborn Action Plan has set a goal of 12 stillbirths per 1000 births by 2030 for all countries.

Methods

From a population-based pregnancy outcome registry, including data from 2010 to 2016 from two sites each in Africa (Zambia and Kenya) and India (Nagpur and Belagavi), as well as sites in Pakistan and Guatemala, we evaluated the stillbirth rates and rates of annual decline as well as risk factors for 427,111 births of which 12,181 were stillbirths.

Results

The mean stillbirth rates for the sites were 21.3 per 1000 births for Africa, 25.3 per 1000 births for India, 56.9 per 1000 births for Pakistan and 19.9 per 1000 births for Guatemala. From 2010 to 2016, across all sites, the mean stillbirth rate declined from 31.7 per 1000 births to 26.4 per 1000 births for an average annual decline of 3.0%. Risk factors for stillbirth were similar across the sites and included maternal age < 20 years and age > 35 years. Compared to parity 1–2, zero parity and parity > 3 were both associated with increased stillbirth risk and compared to women with any prenatal care, women with no prenatal care had significantly increased risk of stillbirth in all sites.

Conclusions

At the current rates of decline, stillbirth rates in these sites will not reach the Every Newborn Action Plan goal of 12 per 1000 births by 2030. More attention to the risk factors and treating the causes of stillbirths will be required to reach the Every Newborn Action Plan goal of stillbirth reduction.

Trial registration

NCT01073475.

Stillbirths in urban Guinea-Bissau: A hospital- and community-based study

Background

Stillbirth rates remain high in many low-income settings, with fresh (intrapartum) stillbirths accounting for a large part due to limited obstetrical care. We aimed to determine the stillbirth rate and identify potentially modifiable factors associated with stillbirth in urban Guinea-Bissau.

Methods

The study was carried out by the Bandim Health Project (BHP), a Health and Demographic Surveillance System site in the capital Bissau. We assessed stillbirth rates in a hospital cohort consisting of all deliveries at the maternity ward at the National Hospital Simão Mendes (HNSM), and in a community cohort, which only included women from the BHP area. Stillbirth was classified as fresh (FSB) if fetal movements were reported on the day of delivery.

Results

From October 1 2007 to April 15 2013, a total of 38164 deliveries were registered at HNSM, among them 3762 stillbirths (99/1000 births). Excluding deliveries referred to the hospital from outside the capital (9.6%), the HNSM stillbirth rate was 2786/34490 births (81/1000). During the same period, 15462 deliveries were recorded in the community cohort. Of these, 768 were stillbirths (50/1000).

Of 11769 hospital deliveries among women from Bissau with data on fetal movement, 866 (74/1000) were stillbirths, and 609 (70.3%) of these were FSB, i.e. potentially preventable. The hospital FSB rate was highest in the evening from 4 pm to midnight (P = 0.04). In the community cohort, antenatal care (ANC) attendance correlated strongly with stillbirth reduction; the stillbirth rate was 71/1000 if the mother attended no ANC consultations vs. 36/1000 if she attended ≥7 consultations (P<0.001).

Conclusion

In Bissau, the stillbirth rate is alarmingly high. The majority of stillbirths are preventable FSB. Improving obstetrical training, labour management (including sufficient intrapartum monitoring and timely intervention) and hospital infrastructure is urgently required. This should be combined with proper community strategies and additional focus on antenatal care.

Small for gestational age and perinatal mortality at term: An audit in a Dutch national cohort study

OBJECTIVE

To assess the underlying risk factors for perinatal mortality in term born small for gestational age infants.

STUDY DESIGN

We performed a population based nationwide cohort study in the Netherlands of 465,532 term born infants from January 2010 to January 2013. Logistic regression analyses were performed. Also audit results were studied for detailed care information.

RESULTS

We studied 162 small for gestational age infants who died in the perinatal period. Risk factors were: gestational age at 37completed weeks (adjusted Odds Ratio (aOR) 2.6, 95% Confidence Interval (CI) 1.6-4.3), male gender (aOR 1.4, 95% CI 1.01-1.9), South Asian ethnicity (aOR 3.6, 95% CI 1.6-8.4), African (aOR 3.5, 95% CI 1.9-6.5) and other non-Western ethnicity (aOR 1.9, CI 1.2-3.1). At 37 completed weeks gestation audit results showed that 26% of the women smoked, 91% were boys and in all but one case death occurred before birth. In 61% of all deceased SGA infants born at 37 completed weeks gestation referral from primary care by independent midwives to the obstetrician took place because of antepartum death before labor.

CONCLUSIONS

Gestational age of 37 completed weeks, male gender, South Asian, African or other non-Western ethnicity and smoking are associated with perinatal mortality in SGA infants. These risk factors concern the complete term population starting at 37 weeks or even earlier. Therefore, it is of utmost importance to develop accurate diagnostic tests to screen for SGA before 36 weeks gestation to prevent perinatal mortality at term in SGA infants.

The Collaborative IPD of Sleep and Stillbirth (Cribss): is maternal going-to-sleep position a risk factor for late stillbirth and does maternal sleep position interact with fetal vulnerability? An individual participant data meta-analysis study protocol

INTRODUCTION

Accumulating evidence has shown an association between maternal supine going-to-sleep position and stillbirth in late pregnancy. Advising women not to go-to-sleep on their back can potentially reduce late stillbirth rate by 9%. However, the association between maternal right-sided going-to-sleep position and stillbirth is inconsistent across studies. Furthermore, individual studies are underpowered to investigate interactions between maternal going-to-sleep position and fetal vulnerability, which is potentially important for producing clear and tailored public health messages on safe going-to-sleep position. We will use individual participant data (IPD) from existing studies to assess whether right-side and supine going-to-sleep positions are independent risk factors for late stillbirth and to test the interaction between going-to-sleep position and fetal vulnerability.

METHODS AND ANALYSIS

An IPD meta-analysis approach will be used using the Cochrane Collaboration-endorsed methodology. We will identify case-control and prospective cohort studies and randomised trials which collected maternal going-to-sleep position data and pregnancy outcome data that included stillbirth. The primary outcome is stillbirth. A one stage procedure meta-analysis, stratified by study with adjustment of a priori confounders will be carried out.

ETHICS AND DISSEMINATION

The IPD meta-analysis has obtained central ethics approval from the New Zealand Health and Disability Ethics Committee, ref: NTX/06/05/054/AM06. Individual studies should also have ethical approval from relevant local ethics committees. Interpretation of the results will be discussed with consumer representatives. Results of the study will be published in peer-reviewed journals and presented at international conferences.

PROSPERO REGISTRATION NUMBER

CRD42017047703.

Causes and risk factors for singleton stillbirth in Japan: Analysis of a nationwide perinatal database, 2013-2014

Over 80% of perinatal mortality in Japan is due to stillbirths after 22 weeks of gestation, with one in 300 families experiencing fetal loss every year. This study aimed to assess causes and risk factors for singleton stillbirth in Japan. A retrospective cross-sectional study was conducted using the Japan Society of Obstetrics and Gynecology Perinatal Database from January 2013 to December 2014. A total of 379,211 births including 2,133 stillbirths were analyzed. Causes of death were classified into eight categories. A multi-level Poisson regression model was used to assess the relationship between stillbirth and key covariates. Causes of death were unknown in 25–40% of stillbirths across gestational age. Placental abnormality accounted for the largest proportion of known causes, followed by umbilical cord abnormality. Stillbirth risk was increased among small-for-gestational-age infants (adjusted relative risk [ARR]: 3.78, 95% confidence interval [CI]: 3.31–4.32) and nulliparous women (ARR: 1.19, 95% CI: 1.05–1.35). Maternal underweight, pregnancy-induced hypertension and oligohydramnios showed a protective effect. Our finding suggests that stillbirths occurring among women with known complications are likely already being prevented. Further reduction in stillbirths must target small-sized fetuses and nulliparous women. Improved recording of the causal pathways of stillbirths is also needed.

Potentially Preventable Stillbirth in a Diverse U.S. Cohort

OBJECTIVE

To estimate the proportion of potentially preventable stillbirths in the United States.

METHODS

We conducted a secondary analysis of 512 stillbirths with complete evaluation enrolled in the Stillbirth Collaborative Research Network from 2006 to 2008. The Stillbirth Collaborative Research Network was a multisite, geographically, racially, and ethnically diverse, population-based case-control study of stillbirth in the United States. Cases of stillbirth underwent standard evaluation that included maternal interview, medical record abstraction, biospecimen collection, postmortem examination, placental pathology, and clinically recommended evaluation. Each stillbirth was assigned probable and possible causes of death using the Initial Causes of Fetal Death algorithm system. For this analysis, we defined potentially preventable stillbirths as those occurring in nonanomalous fetuses, 24 weeks of gestation or greater, and weighing 500 g or greater that were 1) intrapartum, 2) the result of medical complications, 3) the result of placental insufficiency, 4) multiple gestation (excluding twin-twin transfusion), 5) the result of spontaneous preterm birth, or 6) the result of hypertensive disorders of pregnancy.

RESULTS

Of the 512 stillbirths included in our cohort, causes of potentially preventable stillbirth included placental insufficiency (65 [12.7%]), medical complications of pregnancy (31 [6.1%]), hypertensive disorders of pregnancy (20 [3.9%]), preterm labor (16 [3.1%]), intrapartum (nine [1.8%]), and multiple gestations (four [0.8%]). Twenty-seven stillbirths fit two or more categories, leaving 114 (22.3%) potentially preventable stillbirths.

CONCLUSION

Based on our definition, almost one fourth of stillbirths are potentially preventable. Given the predominance of placental insufficiency among stillbirths, identification and management of placental insufficiency may have the most immediate effect on stillbirth reduction.

Bereaved mothers' attitudes regarding autopsy of their stillborn baby

Background

Here we present additional information from the Safe Passage Study, where the effect of alcohol exposure during pregnancy on sudden infant death syndrome and stillbirth was investigated.

Objective

To explore bereaved mothers' attitudes toward obtaining an autopsy on their stillborn baby, and the future implications of consenting or non-consenting to autopsy in retrospect.

Methods

Demographic data was obtained by a questionnaire. A largely qualitative mixed-methods approach was used to meet the aims of the study, using an exploratory and descriptive research design to provide a detailed description of maternal attitudes. A semi-structured questionnaire based on information from literature and reflections on practice was administered during individual interviews.

Results

We interviewed 25 women who had had a recent stillbirth. The time interval between the time of consenting to autopsy and completing this study ranged from 6 to 18 months. Most participants reported that autopsy results provided peace of mind and helped alleviate their feelings of blame. Participants who were unable to comprehend the results reported negative reactions to receiving autopsy results. The majority of participants were of the opinion that they benefited from consenting to autopsy.

Conclusion

Autopsy and the disclosure of its results generally contribute positively to coping following stillbirth.

Association between maternal sleep practices and late stillbirth - findings from a stillbirth case-control study

Objective

To report maternal sleep practices in women who experienced a stillbirth compared with controls with ongoing live pregnancies at similar gestation.

Design

Prospective case‐control study.

Setting

Forty‐one maternity units in the United Kingdom.

Population

Women who had a stillbirth after ≥ 28 weeks’ gestation (n = 291) and women with an ongoing pregnancy at the time of interview (n = 733).

Methods

Data were collected using an interviewer‐administered questionnaire that included questions on maternal sleep practices before pregnancy, in the four weeks prior to, and on the night before the interview/stillbirth.

Main outcome measures

Maternal sleep practices during pregnancy.

Results

In multivariable analysis, supine going‐to‐sleep position the night before stillbirth had a 2.3‐fold increased risk of late stillbirth [adjusted Odds Ratio (aOR) 2.31, 95% CI 1.04–5.11] compared with the left side. In addition, women who had a stillbirth were more likely to report sleep duration less than 5.5 hours on the night before stillbirth (aOR 1.83, 95% CI 1.24–2.68), getting up to the toilet once or less (aOR 2.81, 95% CI 1.85–4.26), and a daytime nap every day (aOR 2.22, 95% CI 1.26–3.94). No interaction was detected between supine going‐to‐sleep position and a small‐for‐gestational‐age infant, maternal body mass index, or gestational age. The population‐attributable risk for supine going‐to‐sleep position was 3.7% (95% CI 0.5–9.2).

Conclusions

This study confirms that supine going‐to‐sleep position is associated with late stillbirth. Further work is required to determine whether intervention(s) can decrease the frequency of supine going‐to‐sleep position and the incidence of late stillbirth.

Tweetable abstract

Supine going‐to‐sleep position is associated with 2.3× increased risk of stillbirth after 28 weeks’ gestation.

Plain Language Summary

Stillbirth, the death of a baby before birth, is a tragedy for mothers and families. One approach to reduce stillbirths is to identify factors that are associated with stillbirth. There are few risk factors for stillbirth that can be easily changed, but this study is looking at identifying how mothers may be able to reduce their risk.

In this study, we interviewed 291 women who had a stillbirth and 733 women who had a live‐born baby from 41 maternity units throughout the UK. The mothers who had a stillbirth were interviewed as soon as practical after their baby died. Mothers who had a live birth were interviewed during their pregnancies at the same times in pregnancy as when the stillbirths occurred. We did not interview mothers who had twins or who had a baby with a major abnormality.

Mothers who went to sleep on their back had at least twice the risk of stillbirth compared with mothers who went to sleep on their left‐hand side. This study suggests that 3.7% of stillbirths after 28 weeks of pregnancy were linked with going to sleep lying on the back. This study also shows that the link between going‐to‐sleep position and late stillbirth was not affected by the duration of pregnancy after 28 weeks, the size of the baby, or the mother's weight. Women who got up to the toilet once or more at night had a reduced risk of stillbirth.

This is the largest of four similar studies that have all shown the same link between the position in which a mother goes to sleep and stillbirth after 28 weeks of pregnancy. Further studies are needed to see whether women can easily change their sleep position in late pregnancy and whether changing the position a mother goes to sleep in reduces stillbirth.

Tweetable abstract

Supine going‐to‐sleep position is associated with 2.3× increased risk of stillbirth after 28 weeks’ gestation.

This paper includes Author Insights, a video abstract available at https://vimeo.com/rcog/authorinsights14967

A population-based study of the effect of pregnancy history on risk of stillbirth

OBJECTIVE

To examine the effect of pregnancy history on the risk of stillbirth.

METHODS

In a population-based cross-sectional study, data were reviewed from all women aged at least 20 years with singleton pregnancies in Finland between 2000 and 2010. The primary outcome-stillbirth-was defined as fetal death after 22 gestational weeks or death of a fetus weighing at least 500 g.

RESULTS

Among 604 047 singleton pregnancies, the prevalence of stillbirth was 3.17 per 1000 deliveries. Prevalence was lowest for multiparous women without previous pregnancy loss after adjusting for major pregnancy complications associated with stillbirth (placenta previa, placental abruption, and pre-eclampsia) and other confounders. Relative to these women, stillbirth prevalence was higher among multiparous women with previous spontaneous abortion and/or stillbirth (adjusted odds ratio [aOR] 1.20, 95% confidence interval [CI] 1.05-1.36), nulliparous women with no previous pregnancy loss (aOR 1.23, 95% CI 1.10-1.38), and nulliparous women with prior spontaneous abortion (aOR 1.43, 95% CI 1.18-1.74).

CONCLUSION

Previous pregnancy loss was found to be an independent risk factor for stillbirth, irrespective of the number of prior deliveries.

Ten years analysis of stillbirth in a tertiary hospital in sub-Sahara Africa: a case control study

Objective

Stillbirth measures provide means to assess adequacy of maternal and perinatal care in a given population. The aim of this study was to describe the determinants of stillbirth in Douala general hospital, Cameroon.

Results

Determinants of stillbirth in this hospital are: maternal age ≥35 years (OR 1.79, 95% CI 1.26–2.54, p = 0.001), pre-eclampsia/eclampsia (OR 2.97, 95% CI 0.87–8.89, p value of 0.03), diabetes in pregnancy (OR 9.97, 95% CI 1.15–86.86, p = 0.03), stillbirth in previous pregnancies (OR 3.94, CI 2.02–7.7, p < 0.0001), inter-pregnancy interval >2 years (OR 2, 06 CI 1.22–3.49; p = 0,006), referral from another hospital (OR 14.16, 95% CI 7.08–28.3, p < 0.0001), gestational age <37 (OR 19.9, 95% CI 12.3–32.2, p < 0.0001) and >42 (OR 6.27, 95% CI = 0.86–45.2, p = 0.096), congenital malformation (OR 11.09, 95% CI 3.2–38,5, p < 0.0001) and birth weight <2500 g (p < 0.0001).

Electronic supplementary material

The online version of this article (doi:10.1186/s13104-017-2787-2) contains supplementary material, which is available to authorized users.

Improved pregnancy outcomes in women with type 1 and type 2 diabetes but substantial clinic-to-clinic variations: a prospective nationwide study

AIMS/HYPOTHESIS

The aim of this prospective nationwide study was to examine antenatal pregnancy care and pregnancy outcomes in women with type 1 and type 2 diabetes, and to describe changes since 2002/2003.

METHODS

This national population-based cohort included 3036 pregnant women with diabetes from 155 maternity clinics in England and Wales who delivered during 2015. The main outcome measures were maternal glycaemic control, preterm delivery (before 37 weeks), infant large for gestational age (LGA), and rates of congenital anomaly, stillbirth and neonatal death.

RESULTS

Of 3036 women, 1563 (51%) had type 1, 1386 (46%) had type 2 and 87 (3%) had other types of diabetes. The percentage of women achieving HbA1c < 6.5% (48 mmol/mol) in early pregnancy varied greatly between clinics (median [interquartile range] 14.3% [7.7-22.2] for type 1, 37.0% [27.3-46.2] for type 2). The number of infants born preterm (21.7% vs 39.7%) and LGA (23.9% vs 46.4%) were lower for women with type 2 compared with type 1 diabetes (both p < 0.001). The prevalence rates for congenital anomaly (46.2/1000 births for type 1, 34.6/1000 births for type 2) and neonatal death (8.1/1000 births for type 1, 11.4/1000 births for type 2) were unchanged since 2002/2003. Stillbirth rates are almost 2.5 times lower than in 2002/2003 (10.7 vs 25.8/1000 births for type 1, p = 0.0012; 10.5 vs 29.2/1000 births for type 2, p = 0.0091).

CONCLUSIONS/INTERPRETATION

Stillbirth rates among women with type 1 and type 2 diabetes have decreased since 2002/2003. Rates of preterm delivery and LGA infants are lower in women with type 2 compared with type 1 diabetes. In women with type 1 diabetes, suboptimal glucose control and high rates of perinatal morbidity persist with substantial variations between clinics.

DATA AVAILABILITY

Further details of the data collection methodology, individual clinic data and the full audit reports for healthcare professionals and service users are available from http://content.digital.nhs.uk/npid .

Altered fetal growth, placental abnormalities, and stillbirth

Background

Worldwide, stillbirth is one of the leading causes of death. Altered fetal growth and placental abnormalities are the strongest and most prevalent known risk factors for stillbirth. The aim of this study was to identify patterns of association between placental abnormalities, fetal growth, and stillbirth.

Methods and findings

Population-based case-control study of all stillbirths and a representative sample of live births in 59 hospitals in 5 geographic areas in the U.S. Fetal growth abnormalities were categorized as small (<10th percentile) and large (>90th percentile) for gestational age at death (stillbirth) or delivery (live birth) using a published algorithm. Placental examination by perinatal pathologists was performed using a standardized protocol. Data were weighted to account for the sampling design. Among 319 singleton stillbirths and 1119 singleton live births at ≥24 weeks at death or delivery respectively, 25 placental findings were investigated. Fifteen findings were significantly associated with stillbirth. Ten of the 15 were also associated with fetal growth abnormalities (single umbilical artery; velamentous insertion; terminal villous immaturity; retroplacental hematoma; parenchymal infarction; intraparenchymal thrombus; avascular villi; placental edema; placental weight; ratio birth weight/placental weight) while 5 of the 15 associated with stillbirth were not associated with fetal growth abnormalities (acute chorioamnionitis of placental membranes; acute chorioamionitis of chorionic plate; chorionic plate vascular degenerative changes; perivillous, intervillous fibrin, fibrinoid deposition; fetal vascular thrombi in the chorionic plate). Five patterns were observed: placental findings associated with (1) stillbirth but not fetal growth abnormalities; (2) fetal growth abnormalities in stillbirths only; (3) fetal growth abnormalities in live births only; (4) fetal growth abnormalities in stillbirths and live births in a similar manner; (5) a different pattern of fetal growth abnormalities in stillbirths and live births.

Conclusions

The patterns of association between placental abnormalities, fetal growth, and stillbirth provide insights into the mechanism of impaired placental function and stillbirth. They also suggest implications for clinical care, especially for placental findings amenable to prenatal diagnosis using ultrasound that may be associated with term stillbirths.

Trends in Fetal and Perinatal Mortality in Korea (2009-2014): Comparison with Japan and the United States

Fetal death is an important indicator of national health care. In Korea, the fetal mortality rate is likely to increase due to advanced maternal age and multiple births, but there is limited research in this field. The authors investigated the characteristics of fetal deaths, the annual changes in the fetal mortality rate and the perinatal mortality rate in Korea, and compared them with those in Japan and the United States. Fetal deaths were restricted to those that occurred at 20 weeks of gestation or more. From 2009 to 2014, the overall mean fetal mortality rate was 8.5 per 1,000 live births and fetal deaths in Korea, 7.1 in Japan and 6.0 in the United States. While the birth rate in Korea declined by 2.1% between 2009 and 2014, the decrease in the number of fetal deaths was 34.5%. The fetal mortality rate in Korea declined by 32.9%, from 11.0 in 2009 to 7.4 in 2014, the largest decline among the 3 countries. In addition, rates for receiving prenatal care increased from 53.9% in 2009 to 75.0% in 2014. Perinatal mortality rate I and II were the lowest in Japan, followed by Korea and the United States, and Korea showed the greatest decrease in rate of perinatal mortality rate II. In this study, we identified that the indices of fetal deaths in Korea are improving rapidly. In order to maintain this trend, improvement of perinatal care level and stronger national medical support policies should be maintained continuously.

Evaluation of the Completeness, Data Quality, and Timeliness of Fetal Mortality Surveillance in Wyoming, 2006-2013

Purpose The number of fetal deaths in the United States each year exceeds that of infant deaths. High quality fetal death certificate data are necessary for states to effectively address preventable fetal deaths. We evaluated completeness of detection of fetal deaths among Wyoming residents that occur out-of-state, quality of cause-of-death data, and timeliness of Wyoming fetal death certificate registration during 2006-2013. Description The numbers of out-of-state fetal deaths among Wyoming residents recorded by Wyoming surveillance and reported by the National Vital Statistics System were compared. Quality of cause-of-death data was assessed by calculating percentage of fetal death certificates completed in Wyoming with ill-defined, unknown, or missing cause-of-death entries. Timeliness was determined using the time between the fetal death and filing of the fetal death certificate with the Wyoming Department of Health Vital Statistics Service. Assessment Wyoming surveillance detected none of the 76 out-of-state fetal deaths among Wyoming residents reported by the National Vital Statistics System. Among 263 fetal death certificates completed in Wyoming and collected by Wyoming surveillance, 108 (41%) contained ill-defined, unknown, or missing cause-of-death entries. Median duration between the fetal death and filing with the Wyoming Vital Statistics Service was 33 days. Conclusion Wyoming fetal mortality surveillance is limited by failure to register out-of-state fetal deaths among residents, poor quality of cause-of-death data, and lack of timeliness. Strategies to improve surveillance include automating interjurisdictional sharing of fetal death data, certifier education, and electronic fetal death registration.

Interventions to prevent stillbirth

Stillbirth is one of the most distressing complications of pregnancy and still occurs far too frequently. The rate of stillbirth has been decreasing worldwide but room for improvement remains even in high-income countries. Risk factors for stillbirth have been identified in an effort to detect those women at increased risk. However, risk factors are non-specific and do not identify most stillbirths. Strategies employed to screen the general population such as assessment of fetal activity, fetal growth screening and biomarkers have also been used to identify increased risk for stillbirth. As with clinical risk factors, these methods are non-specific. Interventions to prevent stillbirth include antenatal testing of high-risk women, ultrasonographic assessments of fetal growth and Doppler velocimetry as well as iatrogenic preterm or term delivery. Additional research into the role of these interventions and better identification of those at high risk for stillbirth will help to achieve further stillbirth reduction.

Perinatal death investigations: What is current practice?

Perinatal death (PD) is a devastating obstetric complication. Determination of cause of death helps in understanding why and how it occurs, and it is an indispensable aid to parents wanting to understand why their baby died and to determine the recurrence risk and management in subsequent pregnancy. Consequently, a perinatal death requires adequate diagnostic investigation. An important first step in the analysis of PD is to identify the case circumstances, including relevant details regarding maternal history, obstetric history and current pregnancy (complications are evaluated and recorded). In the next step, placental examination is suggested in all cases, together with molecular cytogenetic evaluation and fetal autopsy. Investigation for fetal-maternal hemorrhage by Kleihauer is also recommended as standard. In cases where parents do not consent to autopsy, alternative approaches such as minimally invasive postmortem examination, postmortem magnetic resonance imaging, and fetal photographs are good alternatives. After all investigations have been performed it is important to combine findings from the clinical review and investigations together, to identify the most probable cause of death and counsel the parents regarding their loss.

Novel strategies to prevent stillbirth

This article reviews three new and emerging risk factors for stillbirth that may be modifiable or might identify a compromised fetus. We focus on fetal movements, maternal sleep, and maternal diet. Recent studies have suggested than a sudden increase in vigorous fetal activity may be associated with increased risk of stillbirth. We review the papers that have reported this finding and discuss the implications as well as potential future directions for research. There is emerging literature to suggest that maternal sleep position may be a risk for stillbirth, especially if the woman settles to sleep supine. This risk is biologically plausible. How this knowledge may be utilized to assist stillbirth reduction strategies is discussed. Finally, we examine the somewhat limited literature regarding maternal diet and pregnancy outcome. Introducing probiotics into the diet may prove useful, but further work is required. The possible next steps for research are considered, as well as some potential intervention strategies that may ultimately lead to stillbirth reduction.

Understanding determinants of unequal distribution of stillbirth in Tehran, Iran: a concentration index decomposition approach

OBJECTIVE

The present inquiry set to determine the economic inequality in history of stillbirth and understanding determinants of unequal distribution of stillbirth in Tehran, Iran.

METHODS

A population-based cross-sectional study was conducted on 5170 pregnancies in Tehran, Iran, since 2015. Principal component analysis (PCA) was applied to measure the asset-based economic status. Concentration index was used to measure socioeconomic inequality in stillbirth and then decomposed into its determinants.

RESULTS

The concentration index and its 95% CI for stillbirth was -0.121 (-0.235 to -0.002). Decomposition of the concentration index showed that mother's education (50%), mother's occupation (30%), economic status (26%) and father's age (12%) had the highest positive contributions to measured inequality in stillbirth history in Tehran. Mother's age (17%) had the highest negative contribution to inequality.

CONCLUSIONS

Stillbirth is unequally distributed among Iranian women and is mostly concentrated among low economic status people. Mother-related factors had the highest positive and negative contributions to inequality, highlighting specific interventions for mothers to redress inequality.