Diverse placental pathologies as the main causes of fetal death

An unfavorable and a successful pregnancy outcome during and after treatment of gamma heavy chain disease

Gamma heavy chain disease (gHCD) is a rare B-cell lymphoproliferative disorder that mostly occurs after childbearing age. Here we report the first case of gHCD in a pregnant patient that was diagnosed in the second trimester, and another pregnancy in the same patient after initial treatment for gHCD. The former pregnancy ended in intrauterine fetal death, believed to be caused by insufficient maternal blood flow due to multiple placental infarcts. The latter pregnancy course was uneventful. Although we cannot rule out the possibility that the poor outcome of the former pregnancy was due to an unfortunate complication independent of gHCD, the courses of these pregnancies suggest that non-lymphomatous gamma heavy chain may have a significant impact on pregnancy and that its removal by treatment may improve outcomes.

Adipokines in pregnancy

Reproductive success consists of a sequential events chronology, starting with the ovum fertilization, implantation of the embryo, placentation, and cellular processes like proliferation, apoptosis, angiogenesis, endocrinology, or metabolic changes, which taken together finally conduct the birth of healthy offspring. Currently, many factors are known that affect the regulation and proper maintenance of pregnancy in humans, domestic animals, or rodents. Among the determinants of reproductive success should be distinguished: the maternal microenvironment, genes, and proteins as well as numerous pregnancy hormones that regulate the most important processes and ensure organism homeostasis. It is well known that white adipose tissue, as the largest endocrine gland in our body, participates in the synthesis and secretion of numerous hormones belonging to the adipokine family, which also may regulate the course of pregnancy. Unfortunately, overweight and obesity lead to the expansion of adipose tissue in the body, and its excess in both women and animals contributes to changes in the synthesis and release of adipokines, which in turn translates into dramatic changes during pregnancy, including those taking place in the organ that is crucial for the proper progress of pregnancy, i.e. the placenta. In this chapter, we are summarizing the current knowledge about levels of adipokines and their role in the placenta, taking into account the physiological and pathological conditions of pregnancy, e.g. gestational diabetes mellitus, preeclampsia, or intrauterine growth restriction in humans, domestic animals, and rodents.

Placental pathology and neonatal morbidity: exploring the impact of gestational age at birth

AIM

To evaluate placental pathology in term and post-term births, investigate differences in clinical characteristics, and assess the risk of adverse neonatal outcome.

METHODS

This prospective observational study included 315 singleton births with gestational age (GA) > 36 weeks + 6 days meeting the local criteria for referral to placental histopathologic examination. We applied the Amsterdam criteria to classify the placentas. Births were categorized according to GA; early-term (37 weeks + 0 days to 38 weeks + 6 days), term (39 weeks + 0 days to 40 weeks + 6 days), late-term (41 weeks + 0 days to 41 weeks + 6 days), and post-term births (≥ 42 weeks + 0 days). The groups were compared regarding placental pathology findings and clinical characteristics. Adverse neonatal outcomes were defined as 5-minute Apgar score < 7, umbilical cord artery pH < 7.0, admission to the neonatal intensive care unit or intrauterine death. A composite adverse outcome included one or more adverse outcomes. The associations between placental pathology, adverse neonatal outcomes, maternal and pregnancy characteristics were evaluated by logistic regression analysis.

RESULTS

Late-term and post-term births exhibited significantly higher rates of histologic chorioamnionitis (HCA), fetal inflammatory response, clinical chorioamnionitis (CCA) and transfer to neonatal intensive care unit (NICU) compared to early-term and term births. HCA and maternal smoking in pregnancy were associated with adverse outcomes in an adjusted analysis. Nulliparity, CCA, emergency section and increasing GA were all significantly associated with HCA.

CONCLUSIONS

HCA was more prevalent in late and post-term births and was the only factor, along with maternal smoking, that was associated with adverse neonatal outcomes. Since nulliparity, CCA and GA beyond term are associated with HCA, this should alert the clinician and elicit continuous intrapartum monitoring for timely intervention.

Predicting and preventing stillbirth at term

Stillbirth at term affects ∼1 per 1000 pregnancies at term in high income countries. A range of maternal characteristics are associated with stillbirth risk. However, given the low a priori risk of stillbirth, the vast majority of women with clinical risk factors would not experience a stillbirth in the absence of intervention. Stillbirth is the end point of multiple pathways, including both fetal growth restriction and fetal overgrowth. In most term stillbirths there is no mechanistic understanding of the cause of death and a sizeable proportion are completely unexplained. Term stillbirth is potentially preventable by early delivery, providing a rationale for screening. "Omic" analyses of blood taken prior to the onset of some of the conditions associated with stillbirth may help identify women at high risk and allow the potentially harmful intervention of early term medically indicated delivery to be targeted to the pregnancies most likely to benefit.

Stillbirth risk factors, causes and evaluation

Stillbirth impacts 5.73 per 1,000 births in the United States and this rate exceeds that of contemporary high-resource countries.1,2 Risk factors include both demographic and medical characteristics. There are also numerous pathophysiologic mechanisms that can lead to stillbirth. Unfortunately, these risk factors are fairly common, making stillbirth risk stratification and prevention challenging. This is due in part to a large number of unexplained stillbirths. In a large, multi-center study of stillbirths, approximately 24% of stillbirths remained unexplained following thorough, standardized evaluation.3 The number of unexplained stillbirths is unquestionably larger outside of a rigorous study protocol, but real-world data are lacking. This large proportion of unexplained stillbirth cases makes achieving further decreases in the stillbirth rate difficult given lack of understanding of underlying causes in this population. Cause of death identification can be improved with adoption of an evidence-based, comprehensive stillbirth evaluation.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Factors related to fetal demise in cases with congenital heart defects

BACKGROUND

Congenital heart defects are the most common congenital anomaly. Despite the increasing survival of these children, there is still an increased incidence of fetal demise, frequently attributed to cardiac failure. Considering that abnormal placental development has been described in congenital heart disease, our hypothesis is that placental insufficiency may contribute to fetal death in congenital heart disease.

OBJECTIVE

This study aimed to assess cases with fetal congenital heart disease and intrauterine demise, and analyze factors that are related to the demise.

STUDY DESIGN

All congenital heart disease cases diagnosed prenatally during the period January 2002 to January 2021 were selected from the regional prospective congenital heart disease registry, PRECOR. Multiple pregnancies and pregnancies with fetal trisomy 13 or 18, triploidy, and Turner's syndrome were excluded from the analysis, because fetal demise is attributed to the chromosomal abnormality in these cases. Cases were categorized into 4 groups based on the possible cause of fetal death as follows: cardiac failure, additional (genetic) diagnosis, placental insufficiency, and a group in which no cause was found. A separate analysis was performed for isolated congenital heart disease cases.

RESULTS

Of the 4806 cases in the PRECOR registry, 112 had fetal demise, of which 43 were excluded from the analysis (13 multiple pregnancies, 30 genetic). Of these, 47.8% were most likely related to cardiac failure, 42.0% to another (genetic) diagnosis, and 10.1% to placental insufficiency. No cases were allocated to the group with an unknown cause. Only 47.8% of the cases had isolated congenital heart disease, and in this group 21.2% was most likely related to placental insufficiency.

CONCLUSION

This study shows that in addition to cardiac failure and other (genetic) diagnoses, placental factors play an important role in fetal demise in congenital heart disease, especially in cases of isolated heart defects. Therefore, these findings support the importance of regular ultrasonographic assessment of fetal growth and placental function in fetal congenital heart disease.

Placental lesions associated with stillbirth by gestational age, according to feature importance: Results from the stillbirth collaborative research network

INTRODUCTION

Previous studies have identified lesions commonly found in placentas associated with stillbirth but have not distinguished across a range of gestational ages (GAs). The objective of this study was to identify lesions associated with stillbirths at different GAs by adapting methods from the chemical machine learning field to assign lesion importance based on correlation with GA.

METHODS

Placentas from the Stillbirth Collaborative Research Network were examined according to standard protocols. GAs at stillbirth were categorized as: <28 weeks (extreme preterm stillbirth [PTSB]), 28-33'6 weeks (early PTSB), 34-36'6 weeks (late PTSB), ≥37 weeks (term stillbirth). We identified and ranked the most discriminating placental features, as well as those that were similar across GA ranges, using Kernel Principal Covariates Regression (KPCovR).

RESULTS

These analyses included 210 (47.2%) extreme PTSB, 85 (19.1%) early PTSB, 62 (13.9%) late PTSB, and 88 (19.8%) term stillbirths. When we compute the KPCovR, the first principal covariate indicates that there are four lesions (acute funisitis & nucleated fetal red blood cells found in extreme PTSB; multifocal reactive amniocytes & multifocal meconium found in term stillbirth) that distinguish GA ranges among all stillbirths.

DISCUSSION

There are distinct placental lesions present across GA ranges in stillbirths; these lesions are identifiable using sophisticated feature selection. Further investigation may identify histologic changes across gestations that relate to fetal mortality.

Placental Findings in Infants Gestational Age < 34 Weeks and Impact on Short-Term Outcomes

AIM

To analyse placental changes in infants' gestational age < 34 weeks and its correlation to short-term respiratory outcomes or death until hospital discharge.

MATERIAL AND METHODS

Information regarding all in-house born preterm infants born before 34 weeks gestation and born from January 2009 until December 2014 were collected and included among others, placental pathology and relevant data on demographics and outcomes of infants.

RESULTS

Placental abnormalities was found in 157/253 (65.05%) cases. Acute placental inflammation was found to be the most common in both groups of premature neonates, followed by maternal vascular underperfusion. Maternal vascular underperfusion was significantly more common in GA ≤ 27 weeks compared to infants GA 28-33 weeks (35.2% vs. 13.7%; p = 0.018). Similarly, chronic placental inflammation was more common in infants GA ≤ 27 weeks compared to infants GA 28-33 weeks (14.3% vs. 3.3%; p = 0.014). Infants with placental pathology had a lower median birth weight (1460g vs. 1754g; p = 0.001, and were of shorter median GA at birth (31 vs. 32; p = 0.001). Infants with any placental disease had higher rates of death until hospital discharge (10.2% vs. 3.1%; p = 0.039) and higher rates of any stage of bronchopulmonary dysplasia (41.4% vs. 26.0%; p = 0.013). There were no significant differences in mechanical ventilation rates, duration of mechanical ventilation and duration of supplemental oxygen therapy.

CONCLUSION

Identifiable placental abnormalities were found in most infants born < 34 weeks gestation. Placental pathology is associated with increased rates of bronchopulmonary dysplasia and death until hospital discharge.

Interventions, outcomes and outcome measurement instruments in stillbirth care research: A systematic review to inform the development of a core outcome set

BACKGROUND

A core outcome set could address inconsistent outcome reporting and improve evidence for stillbirth care research, which have been identified as an important research priority.

OBJECTIVES

To identify outcomes and outcome measurement instruments reported by studies evaluating interventions after the diagnosis of a stillbirth.

SEARCH STRATEGY

Amed, BNI, CINAHL, ClinicalTrials.gov, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Embase, MEDLINE, PsycINFO, and WHO ICTRP from 1998 to August 2021.

SELECTION CRITERIA

Randomised and non-randomised comparative or non-comparative studies reporting a stillbirth care intervention.

DATA COLLECTION AND ANALYSIS

Interventions, outcomes reported, definitions and outcome measurement tools were extracted.

MAIN RESULTS

Forty randomised and 200 non-randomised studies were included. Fifty-eight different interventions were reported, labour and birth care (52 studies), hospital bereavement care (28 studies), clinical investigations (116 studies), care in a multiple pregnancy (2 studies), psychosocial support (28 studies) and care in a subsequent pregnancy (14 studies). A total of 391 unique outcomes were reported and organised into 14 outcome domains: labour and birth; postpartum; delivery of care; investigations; multiple pregnancy; mental health; emotional functioning; grief and bereavement; social functioning; relationship; whole person; subsequent pregnancy; subsequent children and siblings and economic. A total of 242 outcome measurement instruments were used, with 0-22 tools per outcome.

CONCLUSIONS

Heterogeneity in outcome reporting, outcome definition and measurement tools in care after stillbirth exists. Considerable research gaps on specific intervention types in stillbirth care were identified. A core outcome set is needed to standardise outcome collection and reporting for stillbirth care research.

Endometriosis is associated with pregnancy loss: a nationwide historical cohort study

OBJECTIVE

To study whether endometriosis is associated with pregnancy loss and recurrent pregnancy loss (RPL).

DESIGN

Nationwide historical cohort study with a nested case-control analysis.

SETTING

National health registers.

PATIENT(S)

A total of 29,563 women born between 1957 and 1997 were identified in the national health registers, diagnosed with endometriosis between 1977 and 2017, and age-matched 1:10 with 295,630 women without endometriosis. The number of pregnancy losses was assessed, and data were analyzed with conditional logistic regression.

INTERVENTION(S)

Endometriosis (International Classification of Diseases, 8th Revision, 62530-62539, and International Classification of Diseases, 10th Revision, DN80.0-9).

MAIN OUTCOME MEASURE(S)

The primary outcomes of interest were the numbers of pregnancy losses categorized as 0, 1, 2, and ≥ 3 losses, unadjusted and adjusted for gravidity, and RPL. The secondary outcome measures were the predefined types of pregnancy losses. Pregnancy loss was defined as the spontaneous demise of a pregnancy until 22 weeks of gestation. Primary RPL was defined as 3 or more consecutive pregnancy losses with no prior live birth or stillbirth, and secondary RPL was defined as 1 or more births followed by 3 or more consecutive losses.

RESULT(S)

A total of 18.9%, 3.9%, and 2.1% of ever-pregnant women with endometriosis had 1, 2, and ≥ 3 pregnancy losses compared with 17.3%, 3.5%, and 1.5% of the women without endometriosis, corresponding to the odds ratios of 1.13 (95% confidence interval, 1.09-1.17), 1.18 (1.10-1.26), and 1.44 (1.31-1.59), respectively. When adjusted also for gravidity, the corresponding results were 1.37 (95% confidence interval, 1.32-1.42), 1.75 (1.62-1.89), and 2.57 (2.31-2.85), respectively. The following predefined subgroups of RPL were positively associated with endometriosis: primary; secondary; secondary after giving birth to a boy; after a complicated delivery; and ≥ 3 pregnancy losses before the age of 30 years. Six endometriosis subgroup analyses found an association between endometriosis and pregnancy loss. These analyses were women diagnosed in the 4 decades between 1977 and 2017, women with adenomyosis, and women with adenomyosis only.

CONCLUSION(S)

This nationwide cohort study found endometriosis to be associated with pregnancy loss and RPL, and the association strengthened with an increasing number of losses.

Value of Placental Examination in the Diagnostic Evaluation of Stillbirth

ObjectiveThe aim was to assess the contribution of placental examination in the etiologic investigation of stillbirth. Materials and Methods: A retrospective review of stillbirths that occurred after 14 weeks gestation was conducted for a one-year period. Twin pregnancies and fetuses without placentas were excluded. According to the fetoplacental examination, stillbirths were classified into etiologic groups. Results: A total of 147 stillbirths were selected. They were associated with placental, materno-fetal, fetal and multiple causes in 89 cases (61%), 23 cases (16%), 14 cases (9%) and 13 cases (9%), respectively. Unexplained stillbirths were observed in 8 cases (5%). Placental abnormalities were identified in 132/147 cases (90%). They were consistent with vascular, inflammatory and developmental lesions in 82/132 cases (61%), 28/132 cases (21%) and 18/132 cases (13%), respectively. Conclusion: Placental lesions were the main causes of stillbirth and were predominantly of vascular type including chronic villous hypoxia-ischemia and funicular anomalies.

Delivery characteristics in pregnancies with stillbirth: a retrospective case-control study from a tertiary teaching hospital

OBJECTIVES

We compared delivery characteristics and outcome of women with stillbirth to those with live birth.

METHODS

This was a retrospective case-control study from Helsinki University Hospital, Finland. The study population comprised 214 antepartum singleton stillbirths during 2003-2015. Two age-adjusted controls giving live birth in the same year at the same institution were chosen for each case from the Finnish Medical Birth Register. Delivery characteristics and adverse pregnancy outcomes were compared between the cases and controls, adjusted for gestational age.

RESULTS

Labor induction was more common (86.0 vs. 22.0%, p<0.001, gestational age adjusted odds ratio [aOR] 35.25, 95% confidence interval [CI] 12.37-100.45) and cesarean sections less frequent (9.3 vs. 28.7%, p<0.001, aOR 0.21, 95% CI 0.10-0.47) among women with stillbirth. Duration of labor was significantly shorter among the cases (first stage 240.0 min [115.0-365.0 min] vs. 412.5 min [251.0-574.0 min], p<0.001; second stage 8.0 min [0.0-16.0 min] vs. 15.0 min [4.0-26.0 min], p<0.001). Placental abruption was more common in pregnancies with stillbirth (15.0 vs. 0.9%, p<0.001, aOR 8.52, 95% CI 2.51-28.94) and blood transfusion was needed more often (10.7 vs. 4.4%, p=0.002, aOR 6.5, 95% CI 2.10-20.13). The rates of serious maternal complications were low.

CONCLUSIONS

Most women with stillbirth delivered vaginally without obstetric complications. The duration of labor was shorter in pregnancies with stillbirth but the risk for postpartum interventions and bleeding complications was higher compared to those with live birth.

Placental Findings in Pregnancies Complicated by Maternal Cardiovascular Disease

Background

The incidence of pregnancy in women with cardiovascular disease (CVD) has increased, yet little is known about placental pathology in these women.

Objectives

The objectives of this study were to describe placental pathology in pregnancies complicated by maternal CVD and to compare findings among categories of maternal CVD.

Methods

A retrospective, single-center study was conducted. Pathology reports for 264 placentas from pregnancies complicated by maternal CVD were reviewed for prespecified pathologic findings which were then compared against maternal characteristics.

Results

Placentas were from pregnancies associated with maternal congenital heart disease (n = 171), arrhythmia (n = 43), cardiomyopathy (n = 20), connective tissue disease (n = 20), and valvular heart disease (n = 10). Median maternal age at delivery was 32 years (range: 19-49). Median gestational age at delivery was 39 weeks (range: 25-41). Placental pathology was identified in 75% (199/264) of placentas. Anatomic pathology, primarily small placenta by weight, was present in 45% (119/264) of placentas. Vascular pathology, primarily maternal vascular malperfusion or fetal vascular malperfusion, was seen in 41% (107/264) of placentas. Acute chorioamnionitis and villitis of unknown etiology (VUE) were seen in 23% (61/264) and 11% (28/264) of placentas, respectively. Prevalence of VUE differed across CVD categories (P = 0.008) and was most common in maternal congenital heart disease; there were no differences in anatomic, infectious, and vascular pathologies across CVD categories.

Conclusions

Pregnancies among women with CVD commonly demonstrate abnormal placental findings, especially anatomic and vascular pathology. Prevalence of VUE differed across CVD categories. Otherwise, the incidence of specific pathology findings did not differ based on maternal characteristics.

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

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

Maternal HPV Infection: Effects on Pregnancy Outcome

The human papilloma virus (HPV) infection, caused by a ubiquitous virus typically transmitted through the direct contact of infected organs, either through the skin or mucosa, is the most common sexually transmitted infection, placing young women at a high risk of contracting it. Although the vast majority of cases spontaneously clear within 1-2 years, persistent HPV infection remains a serious concern, as it has repeatedly been linked to the development of multiple malignancies, including cervical, anogenital, and oropharyngeal cancers. Additionally, more recent data suggest a harmful effect of HPV infection on pregnancy. As the maternal hormonal environment and immune system undergo significant changes during pregnancy, the persistence of HPV is arguably favored. Various studies have reported an increased risk of adverse pregnancy outcomes among HPV-positive women, with the clinical impact encompassing a range of conditions, including preterm birth, miscarriage, pregnancy-induced hypertensive disorders (PIHD), intrauterine growth restriction (IUGR), low birth weight, the premature rupture of membranes (PROM), and fetal death. Therefore, understanding the mechanisms employed by HPV that negatively impact pregnancy and assessing potential approaches to counteract them would be of interest in the quest to optimize pregnancy outcomes and improve child survival and health.

Causal analysis of fetal death in high-risk pregnancies

OBJECTIVES

To determine the causes of fetal death among the stillbirths using two classification systems from 22 weeks of gestation in a period of three years in high-risk pregnancies. This is a retrospective observational study.

METHODS

The National Institute of Perinatal Health in Mexico City is a Level 3 care referral center attending high-risk pregnancies from throughout the country. The population consisted of patients with fetal death during a three-year period. Between January 2016 and December 2018, all stillbirths were examined in the Pathology Department by a pathologist and a medical geneticist. Stillbirth was defined as a fetal death occurring after 22 weeks of gestation.

RESULTS

Main outcome measures: Causal analysis of fetal death using the International Statistical Classification of Disease and Related Health Problems-Perinatal Mortality (ICD-PM) and initial causes of fetal death (INCODE) classification systems. A total of 297 stillborn neonates were studied. The distribution of gestational age in antepartum stillbirths (55.2%) showed a bimodal curve, 36% occurred between 24 and 27 weeks and 32% between 32 and 36 weeks. In comparison, the majority (86%) of intrapartum deaths (44.8%) were less than 28 weeks of gestation. Of the 273 women enrolled, 93 (34%) consented to a complete fetal autopsy. The INCODE system showed a present cause in 42%, a possible cause in 54% and a probable cause in 93% of patients.

CONCLUSIONS

The principal causes of antepartum death were fetal abnormalities and pathologic placental conditions and the principal causes of intrapartum death were complications of pregnancy which caused a premature labor and infections.

Abnormal placental perfusion and the risk of stillbirth: a hospital-based retrospective cohort study

Background

A lack of information on specific and interventional factors for stillbirth has made designing preventive strategies difficult, and the stillbirth rate has declined more slowly than the neonatal death rate. We compared the prevalence of stillbirth among the offspring of women with or without abnormal placental perfusion (APP).

Methods

We conducted a hospital-based retrospective cohort study involving women with a singleton pregnancy between 2012 and 2016 (N = 41,632). Multivariate analysis was performed to compare the prevalence of stillbirth in infants exposed to APP (defined as any abnormality in right or left uterine artery pulsatility index or resistance index [UtA-PI, −RI] [e.g., > 95th percentile] or presence of early diastolic notching) with that in those not exposed to APP.

Results

Stillbirths were more common among women with APP than among those with normal placental perfusion (stillbirth rate, 4.3 ‰ vs 0.9 ‰; odds ratio (OR), 4.2; 95% confidence interval (CI), 2.2 to 8.0). The association strengths were consistent across groups of infants exposed to APP that separately defined by abnormality in right or left UtA-PI or -RI (OR ranged from 3.2 to 5.3; all P ≤ 0.008). The associations were slightly stronger for the unexplained stillbirths. Most of the unexplained stillbirth risk was attributed to APP (59.0%), while a foetal sex disparity existed (94.5% for males and 58.0% for females). Women with normal placental perfusion and a male foetus had higher credibility (e.g., higher specificities) in excluding stillbirths than those with APP and a female foetus at any given false negative rate from 1 to 10% (93.4% ~ 94.1% vs. 12.3% ~ 14.0%).

Conclusions

APP is associated with and accounts for most of the unexplained stillbirth risk. Different mechanisms exist between the sexes. The performance of screening for stillbirth may be improved by stratification according to sex and placental perfusion.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03776-8.

Placenta Pathology From Term Born Neonates With Normal or Adverse Outcome

BACKGROUND

The incidence of umbilical cord or placental parenchyma abnormalities associated with mortality or morbidity of term infants is lacking.

METHODS

Placentas of 55 antepartum stillbirths (APD), 21 intrapartum stillbirths (IPD), 12 neonatal deaths (ND), and 80 admissions to a level 3 neonatal intensive care unit (NS) were studied and compared with 439 placentas from neonates from normal term pregnancies and normal outcome after vaginal delivery (NPVD) and with 105 placentas after an elective caesarian sections (NPEC).

RESULTS

NPVD and NPEC placentas showed no or one abnormality in 70% and placentas from stillbirth showed two or more abnormalities in 80% of cases. APD placentas more frequently had a low weight and less formation of terminal villi. Hypercoiling was more often present in all study groups. Severe chronic villitis was almost exclusively present in APD placentas. Chorioamnionitis was significantly more frequent in APD, IPD and NS placentas and funisitis was more often observed in IPD and NS placentas.

CONCLUSION

Multiple placental abnormalities are significantly more frequent in placentas from term neonates with severe perinatal morbidity and mortality. These placental abnormalities are thought to be associated with disturbed oxygen transfer or with inflammation.

A comparison of three classification systems for stillbirth

BACKGROUND

Understanding the causes of perinatal death can provide relevant information to couples, caregivers, and society. Classification systems play a crucial role in identifying the most relevant conditions suggesting preventive measures for decreasing stillbirth (SB). In 2016 the International Classification of Disease to Deaths during the Perinatal Period (ICD-PM) was released with the aim to suggest a universally accepted classification.

METHODS

This is a prospective cohort study that enrolled all SBs occurred in Emilia-Romagna, from 2014 to 2017. We prospectively applied ReCoDe classification and retrospectively used Simplified CODAC classification and ICD-PM. The aim of this study is to compare different classification systems on a cohort of SBs, undergoing a comprehensive workup, to establish what classification minimizes rates of unexplained SB.

RESULTS

We registered 443 SBs. According to ReCoDe the largest category of SB was "placental insufficiency/infarction" (16.9%), followed by "abruptio placentae" (14.2%). Unexplained cases are 16.7%. Gestational age <37 weeks is less frequent in the group of women with unclassified SB (OR 0.50, OR95%CI [0.3-0.8]) against women with classified SB. Considering CODAC the two largest categories are "infarctions or thrombi" (16.3%) and "abruption or retro-placental haematoma" (15.1%), instead only 17.2% of cases remained unexplained.

CONCLUSIONS

Comparing ReCoDe and CODAC we found no real difference in any category. ReCoDe and CODAC better underlines the primary cause of death. ICD-PM reveals to be easily applicable to clinical practice. ICD-PM has the lowest rate of unexplained SBs (9.3%) due to the structure itself and not to a deeper comprehension of death.

Postmortem examination protocol and systematic re-evaluation reduce the proportion of unexplained stillbirths

Background Stillbirth often remains unexplained, mostly due to a lack of any postmortem examination or one that is incomplete and misinterpreted. Methods This retrospective cohort study was conducted at the Department of Obstetrics and Gynecology, Helsinki University Hospital, Finland, and comprised 214 antepartum singleton stillbirths from 2003 to 2015. Maternal and fetal characteristics and the results of the systematic postmortem examination protocol were collected from medical records. Causes of death were divided into 10 specific categories. Re-evaluation of the postmortem examination results followed. Results Based on our systematic protocol, the cause of death was originally defined and reported as such to parents in 133 (62.1%) cases. Re-evaluation of the postmortem examination results revealed the cause of death in an additional 43 (20.1%) cases, with only 23 (10.7%) cases remaining truly unexplained. The most common cause of stillbirth was placental insufficiency in 56 (26.2%) cases. A higher proportion of stillbirths that occurred at ≥39 gestational weeks remained unexplained compared to those that occurred earlier (24.1% vs. 8.6%) (P = 0.02). Conclusion A standardized postmortem examination and a re-evaluation of the results reduced the rate of unexplained stillbirth. Better knowledge of causes of death may have a major impact on the follow-up and outcome of subsequent pregnancies. Also, closer examination and better interpretation of postmortem findings is time-consuming but well worth the effort in order to provide better counseling for the grieving parents.

Altered Levels of Decidual Immune Cell Subsets in Fetal Growth Restriction, Stillbirth, and Placental Pathology

Immune cells are critically involved in placental development and functioning, and inadequate regulation of the maternal immune system is associated with placental pathology and pregnancy complications. This study aimed to explore numbers of decidual immune cells in pregnancies complicated with fetal growth restriction (FGR) and stillbirth (SB), and in placentas with histopathological lesions: maternal vascular malperfusion (MVM), fetal vascular malperfusion (FVM), delayed villous maturation (DVM), chorioamnionitis (CA), and villitis of unknown etiology (VUE). Placental tissue from FGR (n = 250), SB (n = 64), and healthy pregnancies (n = 42) was included. Histopathological lesions were classified according to criteria developed by the Amsterdam Placental Workshop Group. Tissue slides were stained for CD68 (macrophages), CD206 (M2-like macrophages), CD3 (T cells), FOXP3 [regulatory T (Treg) cells], and CD56 [natural killer (NK) cells]. Cell numbers were analyzed in the decidua basalis using computerized morphometry. The Mann-Whitney U-test and Kruskal Wallis test with the Dunn's as post-hoc test were used for statistical analysis. Numbers of CD68⁺ macrophages were higher in FGR compared to healthy pregnancies (p < 0.001), accompanied by lower CD206⁺/CD68⁺ ratios (p < 0.01). In addition, in FGR higher numbers of FOXP3⁺ Treg cells were seen (p < 0.01) with elevated FOXP3⁺/CD3⁺ ratios (p < 0.01). Similarly, in SB elevated FOXP3⁺ Treg cells were found (p < 0.05) with a higher FOXP3+/CD3+ ratio (p < 0.01). Furthermore, a trend toward higher numbers of CD68⁺ macrophages was found (p < 0.1) in SB. Numbers of CD3⁺ and FOXP3⁺ cells were higher in placentas with VUE compared to placentas without lesions (p < 0.01 and p < 0.001), accompanied by higher FOXP3⁺/CD3⁺ ratios (p < 0.01). Elevated numbers of macrophages with a lower M2/total macrophage ratio in FGR suggest a role for a macrophage surplus in its pathogenesis and could specifically indicate involvement of inflammatory macrophages. Higher numbers of FOXP3⁺ Treg cells with higher Treg/total T cell ratios in VUE may be associated with impaired maternal-fetal tolerance and a compensatory response of Treg cells. The abundant presence of placental lesions in the FGR and SB cohorts might explain the increase of Treg/total T cell ratios in these groups. More functionality studies of the observed altered immune cell subsets are needed.

Analysis of relation between placental lesions and perinatal outcome according to Amsterdam criteria: a comparative study

BACKGROUND

To verify the correlation between histological examination of the placenta (HP), classifying the lesions according to the Amsterdam criteria (AC), and the main neonatal pathological patterns.

METHODS

This prospective study carried out at the University of Bari between May 2015 and May 2017,enrolled 350 pregnant women. Complete obstetric history and HP was collected. 380 newborns were also enrolled. The analysis was also carried out by comparing the incidence of the various placental pathologies in the sample of physiological pregnancies (PP), represented by 142 cases, with the incidence of the group with placental anomalies (PA). The statistical software used was STATA MP11.

RESULTS

Respiratory disorders (61 cases) are significantly correlated with generic PA (p=0.006). Neonatal sepsis (15 cases) was significantly correlated with placental inflammation (p=0.035) and villitis of unknown origin (p=0.039).Twin pregnancies (50 cases) were correlated with generic PA (p=0.00001) and late maternal malperfusion (p=0.00001). Congenital cardiopathies (50 cases) were correlated with the villitis of unknown origin and PA (p=0.0000). Preterm birth (145 cases)was correlated with the premature malperfusion (p=0, 0011) and PA (p=0.0000); SGA (low weight in relation to the gestational age - 75 cases) neonates were correlated with the early malperfusion (p=0.00000) and the generic PA (p=0.00000).

CONCLUSIONS

The present study has therefore verified whether in reality the HP can be of great help to the neonatologist in the nosological and therapeutic setting of the pathological newborn. The pathological examination of the placenta is nevertheless essential to clarify the causes of the stillbirths and that these causes are particularly important for the obstetric and neonatal outcome of subsequent pregnancies.

Disorders of placental villous maturation in fetal death

Objective The aims of this study were to ascertain the frequency of disorders of villous maturation in fetal death and to also delineate other placental histopathologic lesions in fetal death. Methods This was a retrospective observational cohort study of fetal deaths occurring among women between January 2004 and January 2016 at Hutzel Women's Hospital, Detroit, MI, USA. Cases comprised fetuses with death beyond 20 weeks' gestation. Fetal deaths with congenital anomalies and multiple gestations were excluded. Controls included pregnant women without medical/obstetrical complications and delivered singleton, term (37-42 weeks) neonate with 5-min Apgar score ≥7 and birthweight between the 10th and 90th percentiles. Results Ninety-two percent (132/143) of placentas with fetal death showed placental histologic lesions. Fetal deaths were associated with (1) higher frequency of disorders of villous maturation [44.0% (64/143) vs. 1.0% (4/405), P < 0.0001, prevalence ratio, 44.6; delayed villous maturation, 22% (31/143); accelerated villous maturation, 20% (28/143); and maturation arrest, 4% (5/143)]; (2) higher frequency of maternal vascular malperfusion lesions [75.5% (108/143) vs. 35.7% (337/944), P < 0.0001, prevalence ratio, 2.1] and fetal vascular malperfusion lesions [88.1% (126/143) vs. 19.7% (186/944), P < 0.0001, prevalence ratio, 4.5]; (3) higher frequency of placental histologic patterns suggestive of hypoxia [59.0% (85/143) vs. 9.3% (82/942), P < 0.0001, prevalence ratio, 6.8]; and (4) higher frequency of chronic inflammatory lesions [53.1% (76/143) vs. 29.9% (282/944), P < 0.001, prevalence ratio 1.8]. Conclusion This study demonstrates that placentas of women with fetal death were 44 times more likely to present disorders of villous maturation compared to placentas of those with normal pregnancy. This suggests that the burden of placental disorders of villous maturation lesions is substantial.

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.

Perinatal outcomes among young donor oocyte recipients

STUDY QUESTION

Is the use of donor oocytes in women <35 years of age associated with an increased risk of adverse perinatal outcomes compared to use of autologous oocytes?

SUMMARY ANSWER

Among fresh assisted reproductive technology (ART) cycles performed in women under age 35, donor oocyte use is associated with a higher risk of preterm birth, low birth weight and stillbirth (when zero embryos were cryopreserved) as compared to autologous oocytes.

WHAT IS KNOWN ALREADY

Previous studies demonstrated elevated risk of poor perinatal outcomes with donor versus autologous oocytes during ART, primarily among older women.

STUDY DESIGN, SIZE, DURATION

Retrospective cohort study using data reported to Centers for Disease Control and Prevention's National ART Surveillance System (NASS) during the period from 2010 to 2015 in order to best reflect advances in clinical practice. Approximately 98% of all US ART cycles are reported to NASS, and discrepancy rates were <6% for all fields evaluated in 2015.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We included all non-banking fresh and frozen ART cycles performed between 2010 and 2015 in women under age 35 using autologous or donor eggs. Cycles using cryopreserved eggs, donated embryos or a gestational carrier were excluded. Among fresh embryo transfer cycles, we calculated predicted marginal proportions to estimate the unadjusted and adjusted risk ratios (aRRs) and 95% confidence intervals (CIs) for the association between donor versus autologous oocyte use and stillbirth, spontaneous abortion, preterm delivery and low birth weight among singleton pregnancies or births. Stillbirth models were stratified by number of embryos cryopreserved. All models were adjusted for patient and treatment characteristics.

MAIN RESULTS AND THE ROLE OF CHANCE

Among the 71 720 singleton pregnancies occurring during 2010-2015, singletons resulting from donor oocytes were more likely to be preterm (15.6% versus 11.0%; aRRs 1.39: CI 1.20-1.61) and have low birth weight (11.8% versus 8.8%; aRRs 1.34; CI 1.16-1.55) than those resulting from autologous oocytes. With zero embryos cryopreserved, donor versus autologous oocyte use was associated with increased risk for stillbirth (2.1% versus 0.6%; aRRs 3.73; CI 1.96-7.11); no association with stillbirth was found when ≥1 embryo was cryopreserved (0.54% versus 0.56%; aRR 1.15; CI 0.59-2.25).

LIMITATIONS, REASONS FOR CAUTION

The data come from a national surveillance system and is thus limited by the accuracy of the data entered by individual providers and clinics. There may be unmeasured differences between women using donor eggs versus their own eggs that could be contributing to the reported associations. Given the large sample size, statistically significant findings may not reflect clinically important variations.

WIDER IMPLICATIONS OF THE FINDINGS

Risks of preterm birth, low birth weight and stillbirth among singleton pregnancies using donor oocytes were increased compared to those using autologous oocytes. Further study regarding the pathophysiology of the potentially increased risks among donor oocyte recipient pregnancy is warranted.

STUDY FUNDING/COMPETING INTEREST(S)

None.

TRIAL REGISTRATION NUMBER

N/A.

Protective effect of metformin on a rat model of lipopolysaccharide-induced preeclampsia

Recent in vitro and clinical studies have found that metformin (MET) may play a preventive or therapeutic role in preeclampsia (PE) and may be a candidate drug for the prevention and/or treatment of PE. In this study, we used lipopolysaccharide (LPS) to induce a PE-like rat model and investigated the intervention effect of MET from the perspectives of clinical manifestations, placental morphology, serum marker for placental injury, systemic inflammatory response and oxidative/nitrative stress, and placental nuclear factor-κB (NF-κB) signaling. The results showed that MET improved LPS-induced hypertension, proteinuria, fetal growth restriction (FGR) and stillbirth, alleviated placental injury and decreased maternal serum marker alpha-fetoprotein (MS-AFP) level; MET suppressed LPS-induced TNF-α and IL-6 productions, reduced oxidative/nitrative stress as evidenced by increased superoxide dismutase (SOD) activity, decreased inducible nitric oxide synthase (iNOS) activity, and decreased levels of malondialdehyde (MDA) and nitric oxide (NO); MET inhibited LPS-induced NF-κB activation in placentas. Based on these findings, it can be concluded that MET is beneficial to the PE-like rat model by protecting placentas from injury, suppressing systemic inflammatory response and oxidative/nitrative stress, and inhibiting placental NF-κB signaling pathway. MET is a promising drug for prevention and/or treatment of PE.

A regional audit system for stillbirth: a way to better understand the phenomenon

Background

Implementation of high-quality national audits for perinatal mortality are needed to improve the registration of all perinatal deaths and the identification of the causes of death. This study aims to evaluate the implementation of a Regional Audit System for Stillbirth in Emilia-Romagna Region, Italy.

Methods

For each stillbirth (≥ 22 weeks of gestation, ≥ 500 g) occurred between January 1, 2014 to December 1, 2016 (n = 332), the same diagnostic workup was performed and a clinical record with data about mother and stillborn was completed. Every case was discussed in a multidisciplinary local audit to assess both the cause of death (ReCoDe classification) and the quality of care. Data were reviewed by the Regional Audit Group. Stillbirth rates, causes of death and the quality of care were established for each case.

Results

Total stillbirth rate was 3.09 per 1000 births (332/107,528). Late stillbirth rate was 2.3 per 1000 (251/107,087). Sixteen stillbirths were not registered by the Regional Birth Register. The most prevalent cause of death was placental disorder (33.3%), followed by fetal (17.6%), cord (14.2%) and maternal disorders (7.6%). Unexplained cases were 14%. Compared to local audits, the regional group attributed different causes of death in 17% of cases. At multivariate analysis, infections were associated with early stillbirths (OR 3.38, CI95% 1.62–7.03) and intrapartum cases (OR 6.64, CI95% 2.61–17.02). Placental disorders were related to growth restriction (OR 1.89, CI95% 1.06–3.36) and were more frequent before term (OR 1.86, CI95% 1.11–3.15). Stillbirths judged possibly/probably preventable with a different management (10.9%) occurred more frequently in non-Italian women and were mainly related to maternal disorders (OR 6.64, CI95% 2.61–17.02).

Conclusions

Regional Audit System for Stillbirth improves the registration of stillbirth and allows to define the causes of death. Moreover, sub-optimal care was recognized, allowing to identify populations which could benefit from preventive measures.

Mechanisms of death in structurally normal stillbirths

Objectives To investigate mechanisms of in utero death in normally formed fetuses by measuring amniotic fluid (AF) biomarkers for hypoxia (erythropoietin [EPO]), myocardial damage (cardiac troponin I [cTnI]) and brain injury (glial fibrillary acidic protein [GFAP]), correlated with risk factors for fetal death and placental histopathology. Methods This retrospective, observational cohort study included intrauterine deaths with transabdominal amniocentesis prior to induction of labor. Women with a normal pregnancy and an indicated amniocentesis at term were randomly selected as controls. AF was assayed for EPO, cTnI and GFAP using commercial immunoassays. Placental histopathology was reviewed, and CD15-immunohistochemistry was used. Analyte concentrations >90th centile for controls were considered "raised". Raised AF EPO, AF cTnI and AF GFAP concentrations were considered evidence of hypoxia, myocardial and brain injury, respectively. Results There were 60 cases and 60 controls. Hypoxia was present in 88% (53/60), myocardial damage in 70% (42/60) and brain injury in 45% (27/60) of fetal deaths. Hypoxic fetuses had evidence of myocardial injury, brain injury or both in 77% (41/53), 49% (26/53) and 13% (7/53) of cases, respectively. Histopathological evidence for placental dysfunction was found in 74% (43/58) of these cases. Conclusion Hypoxia, secondary to placental dysfunction, was found to be the mechanism of death in the majority of fetal deaths among structurally normal fetuses. Ninety-one percent of hypoxic fetal deaths sustained brain, myocardial or both brain and myocardial injuries in utero. Hypoxic myocardial injury was an attributable mechanism of death in 70% of the cases. Non-hypoxic cases may be caused by cardiac arrhythmia secondary to a cardiac conduction defect.

Causes of stillbirths in diabetic and gestational diabetes pregnancies at a NSW tertiary referral hospital

BACKGROUND

Diabetes in pregnancy may result in stillbirth or neonatal death.

AIM

This audit examined stillbirths of mothers with pre-existing diabetes in pregnancy (DIP) and gestational diabetes (GDM) to determine maternal and diabetic characteristics implicated in these deaths.

MATERIALS AND METHODS

A retrospective cohort study was conducted to identify stillbirths occurring in diabetic pregnancies at Westmead Hospital during 2006-2017. Medical records were reviewed to obtain data relating to maternal factors, diabetes history, glycaemic control and cause of death.

RESULTS

There were 37 women (seven with type 1 diabetes [T1DM], 11 with type 2 diabetes [T2DM] and 19 with GDM) who had 38 stillbirths. The leading cause of stillbirth was lethal congenital malformations in nine cases, followed by placental and umbilical abnormalities in six, intra-uterine growth restriction (IUGR) in six, and obstetric factors in four cases. Malformations were predominantly cardiovascular (n = 7), musculoskeletal (n = 5) and gastrointestinal (n = 4). There was no difference in the proportion of stillbirths related to malformations between the DIP and GDM groups (P = 0.22). In the pre-conception period or first trimester, all T1DM subjects and all but two T2DM subjects had HbA1c >7% or there was no measurement. HbA1c was >7% in 6/7 T1DM subjects and 7/11 T2DM subjects at some stage during the pregnancy.

CONCLUSION

Stillbirth remains a problem in diabetic pregnancy in the 21st century. Lethal malformations, placental abnormalities and IUGR were the leading causes of stillbirth related to diabetes. Pre-conception counselling and planning to achieve better glycaemic control in pregnancy needs to be improved.

More Maternal Vascular Malperfusion and Chorioamnionitis in Placentas After Expectant Management vs. Immediate Delivery in Fetal Growth Restriction at (Near) Term: A Further Analysis of the DIGITAT Trial

Objective: Management of late fetal growth restriction (FGR) is limited to adequate fetal monitoring and optimal timing of delivery. The Disproportionate Intrauterine Growth Intervention Trial At Term (DIGITAT) trial compared induction of labor with expectant management in pregnancies at (near) term complicated by suspected FGR. Findings of the DIGITAT trial were that expectant monitoring prolonged pregnancy for 10 days and increased birth weight with only 130 grams. This resulted in more infants born below the 2.3rd percentile compared to induction of labor, respectively, 12.5% in induction of labor and 30.6% in expectant monitoring group. The main placental lesions associated with FGR are maternal vascular malperfusion, fetal vascular malperfusion, and villitis of unknown etiology. We investigated whether placentas of pregnancies complicated with FGR in the expectant monitoring group reveal more and more severe pathology due to pregnancy prolongation. Material and methods: The DIGITAT trial was a multicenter, randomized controlled trial with suspected FGR beyond 36 + 0 weeks. We now analyzed all available cases (n = 191) for placental pathology. The macroscopic details were collected and histological slides were recorded and classified by a single perinatal pathologist, blinded for pregnancy details and outcome. The different placental lesions were scored based on the latest international criteria for placental lesions as defined in the Amsterdam Placental Workshop Group Consensus Statement. Results: The presence of maternal vascular malperfusion and chorioamnionitis were higher in the expectant management group (p < 0.05 and p < 0.01, respectively). No differences in placental weight and maturation of the placenta between the induction of labor and the expectant management group were seen. Fetal vascular malperfusion, villitis of unknown etiology and nucleated red blood cell count did not differ between the groups. Conclusion: Expectant management of late FGR is associated with increased maternal vascular malperfusion and chorioamnionitis. This may have implications for fetal and neonatal outcome, such as programming in the developing child influencing health outcomes later in life.

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.

The structure and utility of the placental pathology report

The placenta is one of the most exciting organs. It is dynamic; its morphology and function continuously develop and adjust over its brief life span. It mediates the physiology of two distinct yet highly interconnected individuals. The pathology that develops in the placenta, and the adaptations the placenta undergoes to mitigate this pathology, may influence the later life health of the mother and baby (Circ Res, 116, 2015, 715; Hum Reprod Update, 17, 2011, 397; Nutr Rev 71, 2013, S88; Placenta, 36, 2015, S20). Pathological placenta examination may reveal macroscopic and microscopic patterns that provide valuable information to the obstetricians, neonatologists, and pediatricians caring for the family. The placenta often plays a key role in understanding adverse fetal outcomes such as hypoxic brain injury, cerebral palsy, fetal growth restriction, stillbirth, and neonatal death (Placenta, 35, 2014, 552; Placenta, 52, 2017, 58; Placenta, 30, 2009, 700; Obstet Gynecol, 114, 2009, 809; Clin Perinatol, 33, 2006, 503; Pediatr Dev Pathol, 11, 2008, 456; Arch Pathol Lab Med, 124, 2000, 1785). Moreover, it may help to understand the pathophysiology of pregnancy, improve management of subsequent pregnancies, and assist in medicolegal assessment. Placental pathologic examination may even provide evidence of susceptibility to adult-onset diseases such as diabetes (Pediatr Dev Pathol, 6, 2003, 54; Diabetes Metab, 36, 2010, 682; BJOG, 113, 2006, 1126; Int J Gynaecol Obstet, 104, 2009, S25; Zentralbl Gynakol, 97, 1975, 875). Pathologic examination of the placenta may thus be of tremendous value, particularly for those women experiencing an adverse pregnancy outcome. However, this potential utility may be entirely wasted, if the findings are not communicated in an effective manner to the appropriate clinicians. An optimized, readily understandable report of pathological findings is essential for clinical utility.

Vascular placental pathology and the relationship between hypertensive disorders of pregnancy and neonatal outcomes in very low birth weight infants

OBJECTIVE

To investigate vascular placental pathology's effect on known associations between hypertensive disorders and four adverse neonatal outcomes-bronchopulmonary dysplasia, intraventricular hemorrhage or periventricular leukomalacia, necrotizing enterocolitis, and death.

STUDY DESIGN

Retrospective cohort of very low birth weight neonates born at a single center (n = 911). Statistical analysis included χ², t test, modified Poisson regression with robust error variance to measure risk, and Wald test. Stratified models assessed the effect of maternal hypertension on neonatal outcomes in those exposed to placental pathology.

RESULTS

Neonates exposed to maternal hypertension and placental pathology had an increased risk of bronchopulmonary dysplasia (relative risk (RR) = 5.23, 95% confidence interval (CI): 2.07, 13.22) compared to those exposed to hypertension without placental pathology (RR = 1.63, 95% CI: 1.14, 2.34; Wald test p = 0.02). Similar, but non-significant, trends also emerged for necrotizing enterocolitis and death.

CONCLUSION

Vascular placental pathology may amplify the risk of adverse outcomes in neonates exposed to hypertension and may mark the extent to which hypertension affects neonates.

Placental physiology monitored by hyperpolarized dynamic 13C magnetic resonance

Placental functions, including transport and metabolism, play essential roles in pregnancy. This study assesses such processes in vivo, from a hyperpolarized MRI perspective. Hyperpolarized urea, bicarbonate, and pyruvate were administered to near-term pregnant rats, and all metabolites displayed distinctive behaviors. Little evidence of placental barrier crossing was observed for bicarbonate, at least within the timescales allowed by ¹³C relaxation. By contrast, urea was observed to cross the placental barrier, with signatures visible from certain fetal organs including the liver. This was further evidenced by the slower decay times observed for urea in placentas vis-à-vis other maternal compartments and validated by mass spectrometric analyses. A clear placental localization, as well as concurrent generation of hyperpolarized lactate, could also be detected for [1-¹³C]pyruvate. These metabolites also exhibited longer lifetimes in the placentas than in maternal arteries, consistent with a metabolic activity occurring past the trophoblastic interface. When extended to a model involving the administration of a preeclampsia-causing chemical, hyperpolarized MR revealed changes in urea's transport, as well as decreases in placental glycolysis vs. the naïve animals. These distinct behaviors highlight the potential of hyperpolarized MR for the early, minimally invasive detection of aberrant placental metabolism.

The prediction of fetal death with a simple maternal blood test at 20-24 weeks: a role for angiogenic index-1 (PlGF/sVEGFR-1 ratio)

BACKGROUND

Fetal death is an obstetrical syndrome that annually affects 2.4 to 3 million pregnancies worldwide, including more than 20,000 in the United States each year. Currently, there is no test available to identify patients at risk for this pregnancy complication.

OBJECTIVE

We sought to determine if maternal plasma concentrations of angiogenic and antiangiogenic factors measured at 24-28 weeks of gestation can predict subsequent fetal death.

STUDY DESIGN

A case-cohort study was designed to include 1000 randomly selected subjects and all remaining fetal deaths (cases) from a cohort of 4006 women with a singleton pregnancy, enrolled at 6-22 weeks of gestation, in a pregnancy biomarker cohort study. The placentas of all fetal deaths were histologically examined by pathologists who used a standardized protocol and were blinded to patient outcomes. Placental growth factor, soluble endoglin, and soluble vascular endothelial growth factor receptor-1 concentrations were measured by enzyme-linked immunosorbent assays. Quantiles of the analyte concentrations (or concentration ratios) were estimated as a function of gestational age among women who delivered a live neonate but did not develop preeclampsia or deliver a small-for-gestational-age newborn. A positive test was defined as analyte concentrations (or ratios) <2.5th and 10th centiles (placental growth factor, placental growth factor/soluble vascular endothelial growth factor receptor-1 [angiogenic index-1] and placental growth factor/soluble endoglin) or >90th and 97.5th centiles (soluble vascular endothelial growth factor receptor-1 and soluble endoglin). Inverse probability weighting was used to reflect the parent cohort when estimating the relative risk.

RESULTS

There were 11 fetal deaths and 829 controls with samples available for analysis between 24-28 weeks of gestation. Three fetal deaths occurred <28 weeks and 8 occurred ≥28 weeks of gestation. The rate of placental lesions consistent with maternal vascular underperfusion was 33.3% (1/3) among those who had a fetal death <28 weeks and 87.5% (7/8) of those who had this complication ≥28 weeks of gestation. The maternal plasma angiogenic index-1 value was <10th centile in 63.6% (7/11) of the fetal death group and in 11.1% (92/829) of the controls. The angiogenic index-1 value was <2.5th centile in 54.5% (6/11) of the fetal death group and in 3.7% (31/829) of the controls. An angiogenic index-1 value <2.5th centile had the largest positive likelihood ratio for predicting fetal death >24 weeks (14.6; 95% confidence interval, 7.7-27.7) and a relative risk of 29.1 (95% confidence interval, 8.8-97.1), followed by soluble endoglin >97.5th centile and placental growth factor/soluble endoglin <2.5th, both with a positive likelihood ratio of 13.7 (95% confidence interval, 7.3-25.8) and a relative risk of 27.4 (95% confidence interval, 8.2-91.2). Among women without a fetal death whose plasma angiogenic index-1 concentration ratio was <2.5th centile, 61% (19/31) developed preeclampsia or delivered a small-for-gestational-age neonate; when the 10th centile was used as the cut-off, 37% (34/92) of women had these adverse outcomes.

CONCLUSION

(1) A maternal plasma angiogenic index-1 value <2.5th centile (0.126) at 24-28 weeks of gestation carries a 29-fold increase in the risk of subsequent fetal death and identifies 55% of subsequent fetal deaths with a false-positive rate of 3.5%; and (2) 61% of women who have a false-positive test result will subsequently experience adverse pregnancy outcomes.

Fetal death: an extreme manifestation of maternal anti-fetal rejection

OBJECTIVE

The aim of this study was to determine the association between chronic placental inflammation and amniotic fluid (AF) markers of maternal anti-fetal rejection as well as the presence of microorganisms in the AF fluid of patients with fetal death.

STUDY DESIGN

This cohort study included 40 patients with fetal death whose placentas were examined for chronic inflammatory lesions and whose AF chemokine ligand (CXCL)10 and interleukin (IL)-6 concentrations were determined by immunoassays. AF was processed for bacteria, mycoplasmas and viruses using cultivation and molecular microbiologic techniques (i.e. PCR-ESI/MS).

RESULTS

(1) The most prevalent placental findings were maternal vascular underperfusion (63.2%, 24/38), followed by chronic inflammatory lesions (57.9%, 22/38); (2) chronic chorioamnionitis (18/38) was three times more frequent than villitis of unknown etiology (6/38); (3) an elevated AF CXCL10 concentration (above the 95th centile) was present in 60% of the cases, and a receiver operating characteristics (ROC)-derived cut-off of 2.9 ng/mL had a sensitivity of 73% and a specificity of 75% in the identification of chronic placental inflammatory lesions; (4) only five cases had microbial invasion of the amniotic cavity, and the presence of microorganisms did not correlate with chronic placental inflammation.

CONCLUSION

In women with unexplained fetal death, there is an association between elevated AF CXCL10 and chronic placental inflammatory lesions. Therefore, we conclude that a subset of patients with fetal death may have endured a breakdown of maternal-fetal tolerance, which cannot be attributed to microorganisms in the amniotic cavity.

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.

Stillbirths at Term: Case Control Study of Risk Factors, Growth Status and Placental Histology

Objective

To investigate the proportion of stillbirths at term associated with abnormal growth using customized birth weight percentiles and to compare histological placental findings both in underweight stillborn fetuses and in live births.

Methods

A retrospective case-control study of 150 singleton term stillbirths. The livebirth control groups included 586 cases of low-risk pregnancies and 153 late fetal growth restriction fetuses. Stillbirths and livebirths from low-risk pregnancies were classified using customized standards for fetal weight at birth, as adequate for gestational age (AGA; 10-90^th percentile), small (SGA; <10^th percentile) or large for gestational age (LGA; >90^th percentile). Placental characteristics in stillbirth were compared with those from livebirths using four categories: inflammation, disruptive, obstructive and adaptive lesions.

Results

There was a higher rate of SGA (26% vs 6%, p<0.001) and LGA fetuses (10.6% vs 5.6%, p<0.05) in the stillbirth group. Among stillbirth fetuses, almost half of the SGA were very low birthweight (≤3°percentile) (12% vs 0.3%, p<0.001). The disruptive (7.3% vs 0.17%;p<0.001), obstructive (54.6% vs 7.5%;p<0.001) and adaptive (46.6% vs 35.8%;p<0.001) findings were significantly more common in than in livebirth-low risk. Placental characteristics of AGA and SGA stillbirth were compared with those of AGA and FGR livebirth. In stillbirths-SGA we found a higher number of disruptive (12.8% vs 0%; p<0.001), obstructive (58.9% vs 23.5%;p<0.001) and adaptive lesions (56.4% vs 49%; p 0.47) than in livebirth-FGR.

Conclusion

The assessment of fetal weight with customized curves can identify fetuses which have not reached their genetically determined growth potential and are therefore at risk for adverse outcomes. Placental evaluation in stillbirths can reveal chronic histological signs that might be useful to clinical assessment, especially in underweight fetuses.

Stillbirths: The Hidden Birth Asphyxia - US and Global Perspectives

Stillbirths are among the most common pregnancy-related adverse outcomes but are more common in low-income and middle-income countries than in high-income countries. In high-income countries, most stillbirths occur early in the preterm period, whereas in low-income and middle-income countries, most occur in term or in late preterm births. In low-income and middle-income countries, conditions, such as prolonged or obstructed labor, placental abruption, preeclampsia/eclampsia, fetal growth restriction, fetal distress, breech and other abnormal presentations, and multiple births, are associated with stillbirth. In high-income countries, placental abnormalities are the most common associations. Globally, fetal asphyxia is likely the most common final pathway to stillbirth.

Thyroid function testing in women who had a stillbirth

CONTEXT

Thyroid dysfunction is thought to be associated with stillbirth. Therefore, thyroid function is often recommended in the diagnostic investigations for stillbirth.

OBJECTIVE

We aimed to evaluate the added value of thyroid function testing in the diagnostic investigations for stillbirth.

DESIGN AND PATIENTS

A nationwide multicentre prospective cohort study in 1025 women who suffered stillbirth >20 weeks of gestation performed between 2002 and 2008. In each woman, an extensive diagnostic work-up was performed, including placental examination and autopsy. TSH and FT4 values below the 2·5th percentile or above the 97·5th percentile according local laboratory reference values were regarded as abnormal. Women with a history of thyroid disease were evaluated separately.

MAIN OUTCOME MEASURES

Thyroid function abnormalities in women with stillbirth.

RESULTS

Of 1025 included women, 21 had a history of thyroid disease (2%). In the 875 with TSH and FT4 results and no history of thyroid disease, 10% had hypothyroxinemia, 4·6% subclinical hypothyroidism, 1·6% overt hypothyroidism and 1·5% subclinical hyperthyroidism. Women with a subclinical hyperthyroidism more often had a foetal death caused by foetal hydrops: 23% vs 2·9% (adjusted OR 10·3, 95% CI 2·5-42).

CONCLUSIONS

Women with a stillbirth had a slightly higher prevalence of overt hypothyroidism, subclinical hypothyroidism and hypothyroxinaemia compared to previous studies on thyroid dysfunction in pregnant women. Given the absence of a strong associations with the cause of stillbirth, and no demonstrated beneficial effects of treating thyroid dysfunction in these women, routine screening after stillbirth is not justified.

Post-mortem magnetic resonance foetal imaging: a study of morphological correlation with conventional autopsy and histopathological findings

The aim of the present study is to offer our experience concerning post-mortem magnetic resonance (PMMR) in foetal death cases and an evaluation of the differences between the findings acquired by PMMR and by forensic autopsy. Fifteen foetuses were recruited from July 2014 to December 2015. These had suffered intrauterine death in women in the 21st to 38th week of gestation who were treated in the emergency department for non-perception of foetal movements. We performed a PMMR on foetuses, 3 ± 1 days on average from the time of death, and then a complete forensic autopsy was performed. All 15 foetuses were examined with a whole-body study protocol, starting from the skull, down to and including the lower limbs. The total time of examination ranged from 20 to 30 min in each case. The external evaluation and description of post-mortem phenomena (maceration), record of the weight and detection and the various measurements of foetal diameters were evaluated before performing autopsy. A complete histopathological study was performed in each case. Out of 15 cases examined, eight were negative for structural anatomical abnormalities and/or diseases, both in the preliminary radiological examination and the traditional autopsy. In the remaining seven cases, pathological findings were detected by PMMR with corresponding results at autopsy. PMMR can provide useful information on foetal medical conditions and result in improved diagnostic classification. It may enable the planning of a more suitable technique before proceeding to autopsy, including focusing on certain aspects of organ pathology otherwise not detectable. The association between PMMR, post-mortem examination and related histological study of the foetus-placenta unit could help reduce the percentage of cases in which the cause of foetal death remains unexplained. Lastly, it may allow a selective sampling of the organ in order to target histological investigations.

Placental histologic patterns and neonatal seizure, in preterm premature rupture of membrane

OBJECTIVE

To investigate the relationship between placenta and perinatal outcomes, in preterm infants born to mothers with preterm premature rupture of fetal membrane (PPROM).

METHODS

We report detailed histology of placentas and perinatal outcomes of infants from 79 PPROM pregnancies. Placental histologic pattern and adverse perinatal outcomes were assessed by logistic regression, adjusting for gestational age at birth, birth weight and interval from rupture of membrane to delivery.

RESULTS

Mean gestational age at membrane rupture was 29.5 ± 3.4 weeks. The incidence of histologic chorioamnionitis (HCA), fetal inflammatory response (FIR) and vascular thrombotic abnormalities in placental histologic examination were 63.3, 25.3 and 78.5%, respectively. Neonates with FIR showed significantly higher incidence of periventricular leukomalacia (PVL) (85% versus 59.3%, p = 0.0364) at brain ultrasonography, than neonates without FIR, in univariate analysis, but not in logistic regression analysis. In logistic regression analysis, the odds ratio of low Apgar score at 1 min in the neonates with clinical chorioamnionitis was 5.009 (95% CI, 1.242-20.195). The odds ratio of neonatal seizure in the neonates with FIR and vascular thrombotic problem was 7.486 (95% CI, 1.617-34.653).

CONCLUSIONS

Our findings support the association between FIR with vascular thrombotic problem in placenta and neonatal seizure, in pregnancies with PPROM.

Maternal plasma angiogenic index-1 (placental growth factor/soluble vascular endothelial growth factor receptor-1) is a biomarker for the burden of placental lesions consistent with uteroplacental underperfusion: a longitudinal case-cohort study

BACKGROUND

Placental lesions consistent with maternal vascular underperfusion (MVU) are thought to be pathogenically linked to preeclampsia, small-for-gestational-age newborns, fetal death, and spontaneous preterm labor and delivery; yet, these lesions cannot be diagnosed antenatally. We previously reported that patients with such conditions and lesions have an abnormal profile of the angiogenic placental growth factor (PlGF) and antiangiogenic factors (eg, soluble vascular endothelial growth factor receptor [sVEGFR]-1).

OBJECTIVE

The objectives of this study were to: (1) examine the relationship between the maternal plasma PlGF/sVEGFR-1 concentration ratio (referred to herein as angiogenic index-1) and the burden of histologic placental features consistent with MVU; and (2) test the hypothesis that angiogenic index-1 can identify patients in the midtrimester who are destined to deliver before 34 weeks of gestation with multiple (ie, ≥3) histologic placental features consistent with MVU.

STUDY DESIGN

A 2-stage case-cohort sampling strategy was used to select participants from among 4006 women with singleton gestations enrolled from 2006 through 2010 in a longitudinal study. Maternal plasma angiogenic index-1 ratios were determined using enzyme-linked immunosorbent assays. Placentas underwent histologic examination according to standardized protocols by experienced pediatric pathologists who were blinded to clinical diagnoses and pregnancy outcomes. The diagnosis of lesions consistent with MVU was made using criteria proposed by the Perinatal Section of the Society for Pediatric Pathology. Weighted analyses were performed to reflect the parent cohort; "n*" is used to reflect weighted frequencies.

RESULTS

(1) Angiogenic index-1 (PlGF/sVEGFR-1) concentration ratios were determined in 7560 plasma samples collected from 1499 study participants; (2) the prevalence of lesions consistent with MVU was 21% (n* = 833.9/3904) and 27% (n* = 11.4/42.7) of women with ≥3 MVU lesions delivered before 34 weeks of gestation; (3) a low angiogenic index-1 (<2.5th quantile for gestational age) in maternal plasma samples obtained within 48 hours of delivery had a sensitivity of 73% (n* = 8.3/11.4; 95% confidence interval [CI], 47-98%), a specificity of 94% (n* = 3130.9/3316.2; 95% CI, 94-95%), a positive likelihood ratio of 12.2, and a negative likelihood ratio of 0.29 in the identification of patients who delivered placentas with ≥3 MVU lesions at <34 weeks; (4) prospectively, at 20-23 weeks of gestation, a maternal plasma concentration of angiogenic index-1 <2.5th quantile identified 70% (n* = 7.2/10.3; 95% CI, 42-98%) of patients who delivered placentas with ≥3 MVU lesions before 34 weeks (specificity, 97% [n* = 2831.3/2918; 95% CI, 96-98%]; positive likelihood ratio, 23; negative likelihood ratio, 0.31); and (5) among women without obstetrical complications who delivered at term, angiogenic index-1 was lower in women with than without placental lesions consistent with MVU (P < .05).

CONCLUSION

Maternal plasma angiogenic index-1 (PlGF/sVEGFR-1) is the first biomarker for the burden of placental lesions consistent with MVU. We propose that an accumulation of these lesions in placentas delivered before 34 weeks is a histologic counterpart of an antiangiogenic profile.

Association of coexisting morphological umbilical cord abnormality and clinical cord compromise with hypoxic and thrombotic placental histology

To assess the usefulness and limitations of placental histology when morphological umbilical cord (UC) abnormality coexists with clinical UC compromise, 5634 consecutive placentas were divided into four groups and statistically compared: group 1-182 placentas from pregnancies with clinical features of UC compromise (variable decelerations, UC entanglement, prolapse, or true knot at delivery); group 2-1355 placentas with abnormal UC morphology or insertion; group 3-152 placentas with at least one phenotype from group 1 and one from group 2; group 4-3945 placentas with no clinical or morphological UC-related phenotypes (control group).Differences were analyzed by ANOVA or χ (2). Of 68 phenotypes studied, 13 clinical and 18 placental phenotypes were statistically significant. In group 1, 2 phenotypes were most common (oligohydramnios and abnormal fetal heart rate tracing). In group 2, 6 phenotypes were most common, including 4 clinical (abnormal umbilical artery Dopplers, nonmacerated stillbirth, multiple pregnancy, and fetal growth restriction) and 2 placental. In group 3, 23 phenotypes were most common, including 7 clinical (gestational hypertension, polyhydramnios, induction of labor, cesarean section, macerated stillbirth, congenital malformations, and abnormal 3rd stage of labor) and 16 placental. The existence of clinical signs of UC compromise alone was associated with the absence of pathomorphological placental abnormalities. However, the coexistence of clinical and abnormal morphological UC phenotypes was statistically significantly associated with placental histological signs of decreased fetal blood flow, hypoxia (acute and chronic post uterine), shallow placental implantation, and/or amnion nodosum. Thus, confirmation of clinical UC compromise should not be expected on placental examination if no morphological UC abnormality or abnormal UC insertion has been found.

Quantitative assessment of placental morphology may identify specific causes of stillbirth

BACKGROUND

Stillbirth is frequently the result of pathological processes involving the placenta. Understanding the significance of specific lesions is hindered by qualitative subjective evaluation. We hypothesised that quantitative assessment of placental morphology would identify alterations between different causes of stillbirth and that placental phenotype would be independent of post-mortem effects and differ between live births and stillbirths with the same condition.

METHODS

Placental tissue was obtained from stillbirths with an established cause of death, those of unknown cause and live births. Image analysis was used to quantify different facets of placental structure including: syncytial nuclear aggregates (SNAs), proliferative cells, blood vessels, leukocytes and trophoblast area. These analyses were then applied to placental tissue from live births and stillbirths associated with fetal growth restriction (FGR), and to placental lobules before and after perfusion of the maternal side of the placental circulation to model post-mortem effects.

RESULTS

Different causes of stillbirth, particularly FGR, cord accident and hypertension had altered placental morphology compared to healthy live births. FGR stillbirths had increased SNAs and trophoblast area and reduced proliferation and villous vascularity; 2 out of 10 stillbirths of unknown cause had similar placental morphology to FGR. Stillbirths with FGR had reduced vascularity, proliferation and trophoblast area compared to FGR live births. Ex vivo perfusion did not reproduce the morphological findings of stillbirth.

CONCLUSION

These preliminary data suggest that addition of quantitative assessment of placental morphology may distinguish between different causes of stillbirth; these changes do not appear to be due to post-mortem effects. Applying quantitative assessment in addition to qualitative assessment might reduce the proportion of unexplained stillbirths.

Isolated Placental Inflammation and Vasculopathy: Clinical Implications in the Extremely Low Birth Weight Infants

The predictive values of placental histopathologies are compromised by a non-segregation of common anomalies. The effects of isolated pure placental inflammation (PI) and vasculopathy-coagulopathy (PV) were compared with normal (NL) placentas in extremely premature infants (ELBW, birth weight < 1000 g). PI infants required lower peak inspiratory pressure on day 3. More infants in PV were oxygen dependence on day 28. PV had an increased risk of intraventricular-periventricular hemorrhage (IVH, OR 4.9, 95% CI 1-24.7, p = 0.05). NL infants were unexposed to PPROM or maternal hypertension, had highest requirement for surfactant, did not develop IVH and periventricular leukomalacia (PVL) and none of them were Caucasian.

CONCLUSIONS

In ELBW infants (1) pure placental vasculopathy-coagulopathy is a risk factor for IVH, (2) a non- pathological intrauterine environment is nonconducive to IVH and PVL, (3) pure placental inflammation is protective for acute pulmonary disease, (4) Caucasian mothers are more susceptible to adverse intrauterine environment.

The role of morphology in mathematical models of placental gas exchange

The performance of the placenta as a gas exchanger has a direct impact on the future health of the newborn. To provide accurate estimates of respiratory gas exchange rates, placenta models need to account for both the physiology of exchange and the organ morphology. While the former has been extensively studied, accounting for the latter is still a challenge. The geometrical complexity of placental structure requires use of carefully crafted approximations. We present here the state of the art of respiratory gas exchange placenta modeling and demonstrate the influence of the morphology description on model predictions. Advantages and shortcomings of various classes of models are discussed, and experimental techniques that may be used for model validation are summarized. Several directions for future development are suggested.