Stillbirth and intrauterine fetal death: role of routine histopathological placental findings to determine cause of death

Reproductive and treatment outcomes in chronic intervillositis of unknown etiology: A systematic review and meta-analysis

Chronic Intervillositis of Unknown Etiology (CIUE) is a rare idiopathic inflammatory disorder of the placenta. The evidence suggests an increased risk for poor obstetrical outcomes and a risk of recurrence as high as 100 %. This meta-analysis examined CIUE prevalence, recurrence, association with autoimmune disorders, reproductive outcomes, pregnancy complications, and the benefits of medical treatments. A systematic review, following PRISMA guidelines, involved a thorough search across multiple databases including Medline, Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Evidence Based Medical Reviews, and Scopus. Out of 590 initially identified studies, 19 studies were included for both qualitative synthesis and meta-analysis after full-text review. Risk of bias was assessed using appropriate tools: The Risk Of Bias In Non-randomized Studies of Interventions tool was applied to twelve studies, while the Joanna Briggs Institute case series critical appraisal tool was used for seven studies. Our findings confirm that CIUE is a rare condition (0.7 %). CIUE is associated with decreased live birth rates (53 %), increased recurrent pregnancy loss (23 %), fetal loss beyond 22 weeks gestation (25 %), a higher prevalence of autoimmune diseases (14 %), and a recurrence rate of 30 % in subsequent pregnancies. Moreover, individuals with CIUE had higher rates of pregnancy complications, including gestational hypertension (19 %), intrauterine growth restriction (45 %), and preterm births (43 %). No significant improvement in live birth rate was observed among treated CIUE patients; however, caution is warranted when interpreting these findings due to the limited sample size. Future research in CIUE is crucial given its rarity and complexity.

Prenatal aneuploidy screening and its impact on stillbirth etiology evaluation

BACKGROUND

Stillbirth impacts 1% of all pregnancies in the USA with the underlying cause often remaining unknown. The objective of this study was to identify if prenatal aneuploidy screening impacted patient agreement to stillbirth evaluation.

METHODS

We performed a retrospective cohort study of patients with a singleton stillbirth after 20 weeks of gestation between October 2017 and December 2021. Demographics and stillbirth evaluation were collected for all patients. Multivariable logistic regression was performed adjusting for variables that were significant in univariate analysis.

RESULTS

A total of 81 persons experienced stillbirth during the study period. Approximately 59.3% of patients had prenatal aneuploidy screening: 39.5% integrated screening, 37.5% non-invasive prenatal testing (NIPT), and 22.9% quad screen. Prenatal genetic screening did not significantly impact patient agreement to placental pathology, serum laboratory evaluation, or fetal autopsy. Patients with NIPT were less likely to have genetic testing sent at the time of stillbirth compared to those with another aneuploidy screening (aOR 0.27, 95% CI 0.07-0.99).

CONCLUSIONS

Prenatal aneuploidy screening was not associated with patient acceptance of stillbirth evaluation. However, patients with NIPT were less likely to pursue further genetic testing during stillbirth evaluation, so further education regarding the benefit of karyotype and microarray should be included in patient counseling.

Morphological, Morphometric, and Histological Evaluation of the Placenta in Cases of Intrauterine Fetal Death

Background The human placenta is a remarkable organ that develops during pregnancy and is crucial in supporting fetal growth and development. The placenta supplies oxygen and nutrients to the fetus and removes waste products from the fetal bloodstream. It also produces hormones that support pregnancy, such as human chorionic gonadotropin, progesterone, and estrogen. Placental insufficiency occurs when the placenta cannot deliver adequate nutrients and oxygen to the fetus. This can result in intrauterine fetal death (IUFD), stillbirth, intrauterine growth restriction, low birth weight, and premature birth. It can also be associated with developmental delays or long-term health issues for the baby. This study aimed to assess the morphologic, morphometric, and histologic changes in the placenta associated with IUFD and compare it with the placenta of live births. Methodology This study was conducted at the Department of Anatomy in collaboration with the Department of Obstetrics and Gynaecology, Integral Institute of Medical Sciences and Research and King George's Medical University Lucknow, where 60 placentas were studied. Placentas were further categorized into the following two groups: Group A, the study group in which placentas from IUFD were taken (n = 30), and Group B, the control group where placentas from live births were taken (n = 30). Morphological and morphometric features of both groups were recorded and compared. Histological features of placentas from IUFD (Group A) were examined after hematoxylin and eosin staining. Results A total of 60 placentas were observed (Group A and Group B). In Group A (IUFD) and Group B (control group), most pregnancies were multigravidas. Round-shaped placentas were the most common type in both groups (Group A = 46.67%, Group B = 66.67%). The average thickness of placentas from Group A (IUFD) cases was significantly reduced (mean thickness = 1.17 ± 0.07 cm) compared to controls in Group B (mean thickness = 2.04 ± 0.93 cm). The p-value obtained was significant at 0.0001. There was a notable reduction in the average placental diameter in Group A (mean diameter = 241.73 ± 65.54 cm) compared to Group B (mean diameter = 263.72 ± 162.67 cm). The p-value obtained was not significant at 0.49. On histopathological examination of the placentas of Group A (IUFD), perivillous fibrin deposition and high-grade calcification were seen in a significantly high number of placentas (70% and 60%, respectively). Conclusions The knowledge of the placenta's morphologic, morphometric, and histologic changes can be utilized to establish the cause of fetal death. In instances of fetal growth limitation and fetal demise that are clinically inexplicable, they can also explain the causes.

Interdependence of placenta and fetal cardiac development

The placenta and fetal heart undergo development concurrently during early pregnancy, and, while human studies have reported associations between placental abnormalities and congenital heart disease (CHD), the nature of this relationship remains incompletely understood. Evidence from animal studies suggests a plausible cause and effect connection between placental abnormalities and fetal CHD. Biomechanical models demonstrate the influence of mechanical forces on cardiac development, whereas genetic models highlight the role of confined placental mutations that can cause some forms of CHD. Similar definitive studies in humans are lacking; however, placental pathologies such as maternal and fetal vascular malperfusion and chronic deciduitis are frequently observed in pregnancies complicated by CHD. Moreover, maternal conditions such as diabetes and pre-eclampsia, which affect placental function, are associated with increased risk of CHD in offspring. Bridging the gap between animal models and human studies is crucial to understanding how placental abnormalities may contribute to human fetal CHD. The next steps will require new methodologies and multidisciplinary approaches combining innovative imaging modalities, comprehensive genomic testing, and histopathology. These studies may eventually lead to preventative strategies for some forms of CHD by targeting placental influences on fetal heart development.

Syncytiotrophoblast Markers Are Downregulated in Placentas from Idiopathic Stillbirths

The trophoblast cells are responsible for the transfer of nutrients between the mother and the foetus and play a major role in placental endocrine function by producing and releasing large amounts of hormones and growth factors. Syncytiotrophoblast cells (STB), formed by the fusion of mononuclear cytotrophoblasts (CTB), constitute the interface between the foetus and the mother and are essential for all of these functions. We performed transcriptome analysis of human placental samples from two control groups-live births (LB), and stillbirths (SB) with a clinically recognised cause-and from our study group, idiopathic stillbirths (iSB). We identified 1172 DEGs in iSB, when comparing with the LB group; however, when we compared iSB with the SB group, only 15 and 12 genes were down- and upregulated in iSB, respectively. An assessment of these DEGs identified 15 commonly downregulated genes in iSB. Among these, several syncytiotrophoblast markers, like genes from the PSG and CSH families, as well as ALPP, KISS1, and CRH, were significantly downregulated in placental samples from iSB. The transcriptome analysis revealed underlying differences at a molecular level involving the syncytiotrophoblast. This suggests that defects in the syncytial layer may underlie unexplained stillbirths, therefore offering insights to improve clinical obstetrics practice.

Assessment of the association between ambient air pollution and stillbirth in the UK: Results from a secondary analysis of the MiNESS case-control study

OBJECTIVE

We examined whether the risk of stillbirth was related to ambient air pollution in a UK population.

DESIGN

Prospective case-control study.

SETTING

Forty-one maternity units in the UK.

POPULATION

Women who had a stillbirth ≥28 weeks' gestation (n = 238) and women with an ongoing pregnancy at the time of interview (n = 597).

METHODS

Secondary analysis of data from the Midlands and North of England Stillbirth case-control study only including participants domiciled within 20 km of fixed air pollution monitoring stations. Pollution exposure was calculated using pollution climate modelling data for NO2 , NOx and PM2.5 . The association between air pollution exposure and stillbirth risk was assessed using multivariable logistic regression adjusting for household income, maternal body mass index (BMI), maternal smoking, Index of Multiple Deprivation quintile and household smoking and parity.

MAIN OUTCOME MEASURE

Stillbirth.

RESULTS

There was no association with whole pregnancy ambient air pollution exposure and stillbirth risk, but there was an association with preconceptual NO2 exposure (adjusted odds ratio [aOR] 1.06, 95% CI 1.01-1.08 per microg/m3 ). Risk of stillbirth was associated with maternal smoking (aOR 2.54, 95% CI 1.38-4.71), nulliparity (aOR 2.16, 95% CI 1.55-3.00), maternal BMI (aOR 1.05, 95% CI 1.01-1.08) and placental abnormalities (aOR 4.07, 95% CI 2.57-6.43).

CONCLUSIONS

Levels of ambient air pollution exposure during pregnancy in the UK, all of were beneath recommended thresholds, are not associated with an increased risk of stillbirth. Periconceptual exposure to NO2 may be associated with increased risk but further work is required to investigate this association.

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.

Risk of adverse perinatal outcomes among women with clinical and subclinical histopathological chorioamnionitis

Introduction

Histologic chorioamnionitis (HCA) is a placental inflammatory condition associated with adverse perinatal outcomes (APOs). This historical cohort study explores the risk of APOs in pregnant women with HCA and compares the impact of clinical chorioamnionitis (CCA) with subclinical chorioamnionitis (SCCA).

Methodology

Placentas were evaluated by a perinatal pathologist tand all women with HCA were included. Two groups were integrated: (1) women with clinical chorioamnionitis (CCA) and (2) women with subclinical chorioamnionitis (SCCA). Additionally, we conducted a secondary analysis to compare the prevalence of APOs among stage 1, 2 and 3 of HCA and the risk of APOs between grades 1 and 2 of HCA. The APOs analyzed were preterm birth, stillbirth, neonatal weight < 1,500 g, neonatal sepsis. Relative risk with 95% confidence interval was calculated.

Results

The study included 41 cases of CCA and 270 cases of SCCA. The mean gestational age at diagnosis and birth was 30.2 ± 5.4 weeks and 32.5 ± 5.1 weeks, for group 1 and 2, respectively. The study also found that women with HCA stage 3 and grade 2 had a higher prevalence and risk of adverse perinatal outcomes.

Discussion

The findings of this study suggest the importance of placental histological study to excluded SCCA, which represents a significant risk to both maternal and neonatal health, contributing to high morbidity and mortality.

SARS-CoV-2-Placental effects and association with stillbirth

SARS-CoV-2 has had a significant impact on pregnancy outcomes due to the effects of the virus and the altered healthcare environment. Stillbirth has been relatively hidden during the COVID-19 pandemic, but a clear link between SARS-CoV-2 and poor fetal outcome emerged in the Alpha and Delta waves. A small minority of women/birthing people who contracted COVID-19 developed SARS-CoV-2 placentitis. In many reported cases this was linked to intrauterine fetal death, although there are cases of delivery just before imminent fetal demise and we shall discuss how some cases are sub-clinical. What is surprising, is that SARS-CoV-2 placentitis is often not associated with severe maternal COVID-19 infection and this makes it difficult to predict. The worst outcomes seem to be with diffuse placental disease which occurs within 21 days of COVID-19 diagnosis. Poor outcomes are often pre-dated by reduced fetal movements but are not associated with ultrasound changes. In some cases, there has also been maternal thrombocytopenia, or coagulation abnormalities, which may provide a clue as to which pregnancies are at risk of fetal demise if a further variant of concern is to emerge. In future, multidisciplinary collaboration and cross-boundary working must be prioritised, to identify quickly such a phenomenon and provide clinicians with clear guidance for reducing fetal death and associated poor outcomes. While we wait to see if COVID-19 brings a future variant of concern, we must focus on appropriate future management of women who have had SARS-CoV-2 placentitis. As a placental condition with an infectious aetiology, SARS-CoV-placentitis is unlikely to recur in a subsequent pregnancy and thus a measured approach to subsequent pregnancy management is needed.

Maternal COVID-19 infection and intrauterine fetal death: Impact on the placenta and fetus

BACKGROUND

Placental damage due to viral infections increases risk of adverse perinatal outcomes. Histopathologic examination of placenta can provide information regarding association between infection and outcome. There is paucity of data describing placental pathology with respect to intrauterine fetal death (IUFD) in pregnant mothers affected with COVID-19.

METHODS

4 fetuses and 10 placentas, including one twin placenta from 9 women with history of IUFD and SARS-CoV-2 infection underwent evaluation. These findings were contrasted with 3 fetuses and 21 gestational age matched placentas from non-infected women with history of IUFD.

RESULTS

Extensive gross placental lesions, mixture of histologic features (maternal/ fetal vascular malperfusion) and isolated cases of massive perivillous fibrin depositon and chronic intervillositis were observed in COVID-IUFD group. There were no distinguishing histologic findings when compared to control. Three fetuses showed signs of intraventricular/intraparenchymal hemorrhage in autopsy.

CONCLUSION

These findings demonstrate that IUFD does not correspond with maternal symptoms and lacks distinctive lesion. However, there was significant placental damage which developed rapidly. These results show that SARS-CoV-2 infection results in rapid placental deterioration and fetal death. This information can be used to educate infected mothers and remind medical professionals, value of monitoring placental function especially following diagnosis of infection.

Placental Pathology Findings in Unexplained Pregnancy Losses

There are approximately 5 million pregnancies per year in the USA, with 1 million ending in miscarriage (a loss occurring prior to 20 weeks of gestation) and over 20,000 ending in stillbirth at or beyond 20 weeks of gestation. As many as 50% of these losses are unexplained. Our objective was to evaluate the effect of expanding the placental pathology diagnostic categories to include the explicit categories of (1) dysmorphic chorionic villi and (2) small placenta in examining previously unexplained losses. Using a clinical database of 1256 previously unexplained losses at 6-43 weeks of gestation, the most prevalent abnormality associated with each loss was determined through examination of its placental pathology slides. Of 1256 cases analyzed from 922 patients, there were 878 (69.9%) miscarriages and 378 (30.1%) antepartum stillbirths. We determined the pathologic diagnoses for 1150/1256 (91.6%) of the entire series, 777/878 (88.5%) of the miscarriages (< 20 weeks' gestation), and 373/378 (98.7%) of the stillbirths (≥ 20 weeks' gestation). The most common pathologic feature observed in unexplained miscarriages was dysmorphic chorionic villi (757 cases; 86.2%), a marker associated with genetic abnormalities. The most common pathologic feature observed in unexplained stillbirths was a small placenta (128 cases; 33.9%). Our classification system reinforced the utility of placental examination for elucidating potential mechanisms behind pregnancy loss. The improved rate of diagnosis appeared to be the result of filling a gap in previous pregnancy loss classification systems via inclusion of the categories of dysmorphic chorionic villi and small placenta.

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.

Risk of stillbirth and adverse pregnancy outcomes in a third pregnancy when an earlier pregnancy has ended in stillbirth

INTRODUCTION

Our study evaluated how a history of stillbirth in either of the first two pregnancies affects the risk of having a stillbirth or other adverse pregnancy outcomes in the third subsequent pregnancy.

MATERIAL AND METHODS

We used the Swedish Medical Birth Register to define a population-based cohort of women who had at least three singleton births from 1973 to 2012. The exposure of interest was a history of stillbirth in either of the first two pregnancies. The primary outcome was subsequent stillbirth in the third pregnancy. Secondary outcomes included: preterm birth, preeclampsia, placental abruption and small-for-gestational-age infant. Adjusted logistic regression was performed including maternal age, body mass index, smoking, diabetes and hypertension. A sensitivity analysis was performed excluding stillbirths associated with congenital anomalies, pregestational and gestational diabetes, hypertension and preterm stillbirths.

RESULTS

The study contained data on 1 316 175 births, including 8911 stillbirths. Compared with women who had two live births, the highest odds of stillbirth in the third pregnancy were observed in women who had two stillbirths (adjusted odds ratio [aOR] 11.40, 95% confidence interval [95% CI] 2.75-47.70), followed by those who had stillbirth in the second birth (live birth-stillbirth) (aOR 3.59, 95% CI 2.58-4.98), but the odds were still elevated in those whose first birth ended in stillbirth (stillbirth-live birth) (aOR 2.35, 1.68, 3.28). Preterm birth, pre-eclampsia and placental abruption followed a similar pattern. The odds of having a small-for-gestational-age infant were highest in women whose first birth ended in stillbirth (aOR 1.93, 95% CI 1.66-2.24). The increased odds of having a stillbirth in a third pregnancy when either of the earlier births ended in stillbirth remained when stillbirths associated with congenital anomalies, pregestational and gestational diabetes, hypertension or preterm stillbirths were excluded. However, when preterm stillbirths were excluded, the strength of the association was reduced.

CONCLUSIONS

Even when they have had a live-born infant, women with a history of stillbirth have an increased risk of adverse pregnancy outcomes; this cannot be solely accounted for by the recurrence of congenital anomalies or maternal medical disorders. This suggests that women with a history of stillbirth should be offered additional surveillance for subsequent pregnancies.

Massive perivillous fibrin deposition: Diagnosis, obstetrical features, and treatment

MPVFD (Massive perivillous fibrin deposition) is placental lesion characterized by extensive massive deposits of fibrin in the intervillous space, extending over at least 25 % of the placental volume. Currently, this pathology can only be detected through histopathological examination of the placenta after a pregnancy has ended. The underlying mechanisms are poorly studied, there is no biomarker available for the diagnosis of MPVFD and treatment protocols are experimental and still lacking. The objective of this study is to systematically review the literature on the associated clinicopathologic features, treatment, and prognosis of MPVFD. We ended up with 17 studies, of these 12 studies were considered relevant for this article and included in the final analysis. All studies reporting MPVFD are retrospective. MPVFD is associated with recurrent miscarriage, intra uterine fetal death (IUFD), intra uterine growth restriction (IUGR) and preterm delivery. The prevalence in pregnancies with a delivery after 22 weeks of gestation was at 1.1 % and even higher to 2.7 % in recurrent early miscarriages. The reported risk of fetal death in MPVFD ranges mainly from 15 to 80 %. Preterm delivery is spontaneous in 50 to 70 % of cases and induced by of a severe intrauterine growth restriction (IUGR) in 30 to 50 % of cases depending on the study. Its causes and treatment are still poorly understood, although several avenues have been explored. This review summarizes current understanding of the prevalence, diagnostic features, clinical consequences, immune pathology, and potential prophylaxis against recurrence in this chronic inflammatory placental syndrome.

Combined prenatal US and post-mortem fetal MRI: can they replace conventional autopsy for fetal body abnormalities?

OBJECTIVES

The acceptance of conventional autopsy (CA), the gold standard method for investigating fetal death, often remains problematic. Post-mortem magnetic resonance imaging (PMMRI) is increasingly advocated, particularly for neurologic malformations. However, PMMRI performances to diagnose non-neurologic malformations remain unclear. We aim to clarify whether a full body CA remains needed after prenatal ultrasound (US) and PMMRI in assessing non-neurologic fetal malformations.

METHODS

In this retrospective IRB-approved study, during a 6-year period, all fetuses who underwent PMMRI, prenatal US, and full body CA were included. Body abnormalities were identified in US, PMMRI, and CA reports. US and PMMRI images were all reviewed. All abnormalities were graded as major (2 points) or minor (1 point). Each technique (US, PMMRI, CA) was given a score by adding all grading points. In each fetus, results were compared for both separate and combined US and PMMRI to CA. Sensitivity and specificity were calculated for detecting major abnormalities.

RESULTS

Fifty fetuses were included. The score of CA, US, and PMMRI was respectively 53, 37, and 46. Compared with US-PMMRI, CA added information in 2 cases (4%) with major abnormalities and 7 cases (14%) with minor abnormalities. PMMRI and US were concordant in 36/50 (72%) fetuses. Separate US/PMMRI sensitivities and specificities for detecting major body malformations respectively were 80%/80% and 100%/94%. Combined US-PMMRI had a sensitivity of 90% and a specificity of 94%. Two cardiac malformations (2/6) were only described by CA.

CONCLUSIONS

After prenatal US and PMMRI, few additional fetal body malformations are discovered with CA. Nevertheless, fetal heart autopsy remains mandatory.

CLINICAL RELEVANCE STATEMENT

A cardiac conventional autopsy complemented by prenatal ultrasound and post-mortem MRI allows to detect all major fetal body abnormalities. With this efficient and much less invasive approach, a higher acceptance rate of fetal autopsy can be expected.

KEY POINTS

• Excepting cardiac malformations, most major fetal body malformations can reliably be identified by prenatal US combined with post-mortem MRI. • In the post-mortem diagnosis of fetal body malformations, a conventional autopsy limited to the fetal heart might replace a full body autopsy after a well-conducted prenatal US and post-mortem MRI.

Cytology Techniques Can Provide Insight into Human Placental Structure Including Syncytiotrophoblast Nuclear Spatial Organisation

The aim of this study was to provide the first systematic description of human placental cytology appearances and to investigate syncytiotrophoblast nuclear organisation patterns using cytology techniques. Term placentas from normal pregnancies were sampled using fine-needle aspiration (FNA) and direct scrapes. Standard histological examination was also performed to exclude pathological changes in the placentas being studied. Both Papanicolaou-stained cytospin preparations and air-dried Giemsa slides from FNA provided high-quality material for cytological assessment with good cellularity. Among the key features of the cytology preparations were villous "microbiopsies" that allowed for the three-dimensional appreciation of villous branching patterns. Cytological appearances, including nuclear characteristics of villous cytotrophoblast and syncytiotrophoblast, were also well demonstrated. In microbiopsies and detached villous trophoblast sheets, complex patterns of syncytiotrophoblast nuclear organisation, not previously described cytologically, were observed, including irregular spacing of nuclei, syncytioplasm windows and linear nuclear arrangements. This study showed that placental cytology (a) provides technically excellent material for cytological evaluation, (b) confirms the presence of complex nuclear organisational patterns in the syncytiotrophoblast by eliminating the possibility of tangential sectioning artefact, (c) provides superior nuclear detail over standard histological sections and (d) may be an untapped research resource for the investigation of normal and pathological processes because of its ability to look at the placenta in a novel way and through its potential for both ex vivo and in vivo placental sampling.

Etiology of stillbirth in a tertiary care center: a retrospective cohort study assessing ultrasound, laboratory, and pathology investigations

BACKGROUND

Canadian stillbirth data are limited, and a significant proportion of pregnancies resulting in stillbirth have no attributable cause. The objective of this study was to characterize stillbirth case investigations and management at a tertiary care hospital in Ontario, Canada.

METHODS

This was a retrospective chart review study of all cases of singleton stillbirth at The Ottawa Hospital between 1 January 2012 and 31 December 2017. Terminations and multiples stillbirths were excluded. Chart reviews were conducted to extract maternal sociodemographic, obstetrical, and fetal characteristics, including results from antenatal ultrasounds, autopsy, placenta pathology, and laboratory investigations.

RESULTS

A total of 155 eligible cases of stillbirth were identified, resulting in a 6-year stillbirth rate of 4.2 per 1000 total births. The median maternal age was 31.0 years (IQR: 29.0, 35.0) and the median gestational age at delivery was 28 weeks (IQR: 24, 35). A total of 9 (5.8%) pregnant individuals had a history of previous stillbirth. Of the 155 stillbirths, 35% underwent the full suite of post-loss laboratory, placental, and fetal autopsy investigations. 63.2% of cases had post-loss laboratory investigations completed. 76% and 71% of cases had fetal autopsy and placenta pathology evaluations completed, respectively. Antenatal characteristics associated with stillbirth included fetal anomalies/genetic markers (27.1%), umbilical cord and placental anomalies (24.5%), fetal growth abnormalities (27.7%), cervical/uterine abnormalities (11.6%), and amniotic fluid abnormalities (25.1%). The most common autopsy findings included evidence of infection (22.7%), fetal anomalies (12.6%), and fetal hypoxia (10%). The most common placental pathology findings included features of placental insufficiency (21.8%), retroplacental abnormalities (16.3%), and umbilical cord accident/infarct (15.4%).

CONCLUSIONS

Our findings demonstrate that as many as two-thirds of singleton stillbirth cases at our center did not receive the post-perinatal loss investigations recommended by clinical practice guidelines. More thorough collection of post-stillbirth data at all levels (institutional, provincial, national) is warranted to improve our understanding of stillbirth epidemiology, etiology, and management in Canada.

Chance of healthy versus adverse outcome in subsequent pregnancy after previous loss beyond 16 weeks: data from a specialized follow-up clinic

PURPOSE

Women with a previous fetal demise have a 2-20 fold increased risk of another stillbirth in a subsequent pregnancy when compared to those who have had a live birth. Despite this, there is limited research regarding the management and outcomes of subsequent pregnancies. This study was conducted to accurately quantify the chances of a woman having a healthy subsequent pregnancy after a pregnancy loss.

METHODS

A retrospective study was conducted at a tertiary-level unit between March 2019 and April 2021. We collected data on all women with a history of previous fetal demise attending a specialized perinatal history clinic and compared the risk of subsequent stillbirth to those with a normal pregnancy outcome. Outcome data included birth outcome, obstetric and medical complications, gestational age and birth weight and mode of delivery. Those who had healthy subsequent pregnancies were compared with those who experienced adverse outcomes.

RESULTS

A total of 101 cases were reviewed. Ninety-six women with subsequent pregnancies after a history of fetal demise from 16 weeks were included. Seventy-nine percent of women (n = 76) delivered a baby at term, without complications. Overall, 2.1% had repeat pregnancy losses (n = 2) and 2.1% delivered babies with fetal growth restriction (n = 2). There were no cases of abruption in a subsequent pregnancy. Eighteen neonates were delivered prematurely (18.4%), 15 of these (83.3%) were due to iatrogenic causes and three (16.7%) were spontaneous. In univariable logistic regression analyses, those with adverse outcomes in subsequent pregnancies had greater odds of pre-eclampsia (Odds ratio *(OR) = 3.89, 95% CI = 1.05-14.43, p = .042) and fetal growth restriction (OR = 4.58, 95% CI = 1.41-14.82, p = 0.011) in previous pregnancies compared to those with healthy outcomes. However, in multivariable logistic regression analyses, neither variable had a significant odds ratio (OR = 2.03, 95% CI = 0.44-9.39, p = .366 and OR = 3.42, 95% CI = 0.90 - 13.09, p = .072 for pre-eclampsia and FGR, respectively).

CONCLUSION

Four in five women had a healthy subsequent pregnancy. This is a reassuring figure for women when contemplating another pregnancy, particularly if cared for in a specialist clinic.

The utility of complete blood parameter indices to predict stillbirths

OBJECTIVE

In this study, we aimed to investigate the relationship between unexplained stillbirth (SB) cases and the complete blood parameter indices and we compared them with uncomplicated healthy cases.

METHODS

Patients diagnosed with unexplained SB cases in a tertiary center between 2019-2022 were included in this retrospective case-control study. The gestational age threshold for SBs was accepted as births after the 20th week of pregnancy. Consecutive patients with no adverse obstetric outcomes were accepted as the control group. Patients' complete blood parameter results at the time of the first admission to the hospital until 14 weeks were labeled as "1'' and at the time of delivery were labeled as "2'' and recorded. As inflammatory parameters, neutrophile-lymphocyte ratio, derivated neutrophile-lymphocyte ratio, platelet-lymphocyte ratio, lymphocyte-monocyte ratio (LMR), and hemoglobin-lymphocyte ratio (HLR) were calculated from complete blood results and recorded.

RESULTS

There were statistically significant differences between the groups' LMR1 (p = .040). Additionally, whereas HLR1 of the study group was 0.693 (0.38-2.72), it was 0.645 (0.15-1.82) in the control group (p = .026). However, the HLR2 of the study group was significantly lower than the control group (p = .021).

CONCLUSION

Necessary precautions such as fetal biophysical profile examination can be taken more frequently in the antenatal follow-up in patients considered to be at high risk of SB by using HLR. It is a novel marker that can be easily accessible and calculated from the complete blood parameters.

Macroscopic lesions of maternal and fetal vascular malperfusion in stillborn placentas: Diagnosis in the absence of microscopic histopathological examination

INTRODUCTION

Lesions of maternal vascular malperfusion (MVM) and fetal vascular malperfusion (FVM) are common in placentas associated with both stillbirth and live birth. The objective of this study was to identify lesions present more commonly in stillborn placentas and those most indicative of MVM and FVM without microscopic pathologic evaluation.

METHODS

Data were derived from the Stillbirth Collaborative Research Network. Lesions were identified according to standard protocols published previously and categorized as either MVM or FVM according to the Amsterdam Placental Workshop Group Consensus Statement and macroscopic "umbilical cord at risk" findings. Multivariate logistic regression was used to determine the odds of stillbirth with macroscopic findings of MVM or FVM.

RESULTS

595 stillbirths and 1,305 live births were analyzed. FVM lesions (85.2%) were marginally more common (though not statistically different) in stillbirths compared to MVM lesions (81.3%). Macroscopic findings of both MVM and FVM were more common in stillbirths versus livebirths (p < 0.001). Odds ratios of macroscopic MVM and FVM lesions for stillbirth, adjusted for gestational age at delivery, maternal race (minority), ethnicity (Hispanic), age, and history of hypertension or diabetes, were 1.48 (95% CI 1.30-1.69) and 1.34 (95% CI 1.18-1.53), respectively.

DISCUSSION

Macroscopic features of MVM and FVM are associated with higher odds of stillbirth versus live birth even when controlled for gestational age and maternal factors, which may be a useful clue in determining the pathophysiology of these events. This information is also useful for pathologists when microscopic examination is not available.

Comparison of Prenatal and Postmortem Diagnoses from 251 Fetal Autopsies: High Rate of Placenta Pathologies, Low Rate of Discrepancies

Background: In cases of intrauterine fetal death (IUFD), autopsy and placenta pathology can provide additional information to sonographic findings. We assessed the frequency of prenatally missed relevant diagnoses. Materials and methods: A retrospective evaluation of fetal autopsies from 2006 to 2021 was performed and were classified as: i) agreement, ii) cases where autopsy revealed additional findings, or iii) postmortem findings which changed the diagnosis. Results: A total of 199/251 spontaneous IUFD and 52/251 induced abortions were included. In spontaneous IUFD, placenta pathologies were the leading cause of death (89%). Full agreement was found in most cases (91% and 87% in spontaneous IUFD and induced abortion, respectively), while additional findings (7% and 12%) and major discrepancies (each 2%) were detected less frequently. Conclusion: In some cases where major findings were missed, autopsy could establish a diagnosis.

Comparison of the Autopsy and Placental Findings in Second vs Third Trimester Stillbirth

BACKGROUND

The pathology of second trimester fetal loss is not well-characterized due to lack of comprehensive autopsy studies. The purpose of this study is to compare autopsy pathology of second trimester and third trimester stillbirth.

METHODS

In this retrospective cohort study, fetal autopsies performed in-house with complete placental examination were included. From autopsy reports, maternal demographics, gestational age, sex, body and placental weight, congenital anomalies, and cause of death (COD) were obtained. Immediate COD was coded "probable" or "possible" according to Initial Causes of Fetal Death (INCODE).

RESULTS

Among 68 second trimester and 54 third trimester fetal autopsies, at least 1 probable COD was identified in 59/68 (87%) second trimester and 44/54 (81%) third trimester cases. 42/68 (62%) second trimester and 28/54 (52%) third trimester fetuses had probable COD secondary to placental pathology. Among placental causes, 29/42 (69%) second trimester and 14/28 (50%) third trimester stillbirths were related to compromised fetal microcirculation with umbilical cord abnormality.

CONCLUSIONS

Among stillborn first and second trimester fetuses who undergo autopsy, the most prevalent COD is pathologic placental conditions, particularly those associated with umbilical cord obstruction. This study stresses the importance of placenta examination for establishing COD in both second and third trimester fetuses.

Placental pathology reports: A qualitative study in a US university hospital setting on perceived clinical utility and areas for improvement

OBJECTIVE

To explore how placental pathology is currently used by clinicians and what placental information would be most useful in the immediate hours after delivery.

STUDY DESIGN

We used a qualitative study design to conduct in-depth, semi-structured interviews with obstetric and neonatal clinicians who provide delivery or postpartum care at an academic medical center in the US (n = 19). Interviews were transcribed and analyzed using descriptive content analysis.

RESULTS

Clinicians valued placental pathology information yet cited multiple barriers that prevent the consistent use of pathology. Four main themes were identified. First, the placenta is sent to pathology for consistent reasons, however, the pathology report is accessed by clinicians inconsistently due to key barriers: difficult to find in the electronic medical record, understand, and get quickly. Second, clinicians value placental pathology for explanatory capability as well as for contributions to current and future care, particularly when there is fetal growth restriction, stillbirth, or antibiotic use. Third, a rapid placental exam (specifically including placental weight, infection, infarction, and overall assessment) would be helpful in providing clinical care. Fourth, placental pathology reports that connect clinically relevant findings (similar to radiology) and that are written with plain, standardized language and that non-pathologists can more readily understand are preferred.

CONCLUSION

Placental pathology is important to clinicians that care for mothers and newborns (particularly those that are critically ill) after birth, yet many problems stand in the way of its usefulness. Hospital administrators, perinatal pathologists, and clinicians should work together to improve access to and contents of reports. Support for new methods to provide quick placenta information is warranted.

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.

Association of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection With Maternal Mortality and Neonatal Birth Outcomes in Botswana by Human Immunodeficiency Virus Status

OBJECTIVE

To evaluate the combined association of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and human immunodeficiency virus (HIV) infection on adverse birth outcomes in an HIV-endemic region.

METHODS

The Tsepamo Study abstracts data from antenatal and obstetric records in government maternity wards across Botswana. We assessed maternal mortality and adverse birth outcomes for all singleton pregnancies from September 2020 to mid-November 2021 at 13 Tsepamo sites among individuals with documented SARS-CoV-2 screening tests and known HIV status.

RESULTS

Of 20,410 individuals who gave birth, 11,483 (56.3%) were screened for SARS-CoV-2 infection; 4.7% tested positive. People living with HIV were more likely to test positive (144/2,421, 5.9%) than those without HIV (392/9,030, 4.3%) (P=.001). Maternal deaths occurred in 3.7% of those who had a positive SARS-CoV-2 test result compared with 0.1% of those who tested negative (adjusted relative risk [aRR] 31.6, 95% CI 15.4-64.7). Maternal mortality did not differ by HIV status. The offspring of individuals with SARS-CoV-2 infection experienced more overall adverse birth outcomes (34.5% vs 26.6%; aRR 1.2, 95% CI 1.1-1.4), severe adverse birth outcomes (13.6% vs 9.8%; aRR 1.2, 95% CI 1.0-1.5), preterm delivery (21.4% vs 13.4%; aRR 1.4, 95% CI 1.2-1.7), and stillbirth (5.6% vs 2.7%; aRR 1.7 95% CI 1.2-2.5). Neonates exposed to SARS-CoV-2 and HIV infection had the highest prevalence of adverse birth outcomes (43.1% vs 22.6%; aRR 1.7, 95% CI 1.4-2.0).

CONCLUSION

Infection with SARS-CoV-2 at the time of delivery was associated with 3.7% maternal mortality and 5.6% stillbirth in Botswana. Most adverse birth outcomes were worse among neonates exposed to both SARS-CoV-2 and HIV infection.

Examination of a Stillbirth Workup: A Rural Statewide Experience

OBJECTIVE

The objective of our study was to determine whether recommended assessments were conducted on stillbirths delivered in our predominantly rural state.

METHODS

This was a descriptive study of stillbirths delivered in a rural state and included in one site of the Birth Defects Study to Evaluate Pregnancy Exposures stillbirth study. Hospital and fetal death records were examined to determine whether the following areas were evaluated: genetic testing (noninvasive perinatal testing, quad screen, amniocentesis/chorionic villus sampling with karyotype, microarrays, fetal tissue specimen), placenta/membrane/cord sent for pathologic examination, examination of the stillbirth after delivery by the healthcare provider, and fetal autopsy was performed.

RESULTS

From July 1, 2015 to June 30, 2020, there were 1108 stillbirths delivered in Arkansas. The most frequent assessments undertaken were placental pathology (72%), genetic testing (67%), fetal inspection (31%), and autopsy (13%). All four assessments were done in 2% of stillbirth cases, three assessments in 27%, two assessments in 47%, one assessment in 14%, and no assessment in 15%. There was no association between stillbirth assessment evaluation by gestational age (<28 weeks and > 28 weeks; P = 0.221); however, there was an overall association between hospital delivery volume with number of components completed (P < 0.0001). Hospitals with >2000 deliveries had a higher proportion of three or four completions compared with those hospitals with <1000 deliveries or 1000 to 2000 deliveries (P = 0.021 and P < 0.0001).

CONCLUSIONS

Fetal stillbirth assessment is suboptimal in our rural state, with 15% of stillbirths having no assessment and only 2% having all four assessments. There is no association between stillbirth assessment and gestational age (<28 weeks vs >28 weeks), but there is a correlation between delivery volume and stillbirth assessment.

Toward a new taxonomy of obstetrical disease: improved performance of maternal blood biomarkers for the great obstetrical syndromes when classified according to placental pathology

BACKGROUND

The major challenge for obstetrics is the prediction and prevention of the great obstetrical syndromes. We propose that defining obstetrical diseases by the combination of clinical presentation and disease mechanisms as inferred by placental pathology will aid in the discovery of biomarkers and add specificity to those already known.

OBJECTIVE

To describe the longitudinal profile of placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1), and the PlGF/sFlt-1 ratio throughout gestation, and to determine whether the association between abnormal biomarker profiles and obstetrical syndromes is strengthened by information derived from placental examination, eg, the presence or absence of placental lesions of maternal vascular malperfusion.

STUDY DESIGN

This retrospective case cohort study was based on a parent cohort of 4006 pregnant women enrolled prospectively. The case cohort of 1499 pregnant women included 1000 randomly selected patients from the parent cohort and all additional patients with obstetrical syndromes from the parent cohort. Pregnant women were classified into six groups: 1) term delivery without pregnancy complications (n=540; control); 2) preterm labor and delivery (n=203); 3) preterm premature rupture of the membranes (n=112); 4) preeclampsia (n=230); 5) small-for-gestational-age neonate (n=334); and 6) other pregnancy complications (n=182). Maternal plasma concentrations of PlGF and sFlt-1 were determined by enzyme-linked immunosorbent assays in 7560 longitudinal samples. Placental pathologists, masked to clinical outcomes, diagnosed the presence or absence of placental lesions of maternal vascular malperfusion. Comparisons between mean biomarker concentrations in cases and controls were performed by utilizing longitudinal generalized additive models. Comparisons were made between controls and each obstetrical syndrome with and without subclassifying cases according to the presence or absence of placental lesions of maternal vascular malperfusion.

RESULTS

1) When obstetrical syndromes are classified based on the presence or absence of placental lesions of maternal vascular malperfusion, significant differences in the mean plasma concentrations of PlGF, sFlt-1, and the PlGF/sFlt-1 ratio between cases and controls emerge earlier in gestation; 2) the strength of association between an abnormal PlGF/sFlt-1 ratio and the occurrence of obstetrical syndromes increases when placental lesions of maternal vascular malperfusion are present (adjusted odds ratio [aOR], 13.6 vs 6.7 for preeclampsia; aOR, 8.1 vs 4.4 for small-for-gestational-age neonates; aOR, 5.5 vs 2.1 for preterm premature rupture of the membranes; and aOR, 3.3 vs 2.1 for preterm labor (all P<0.05); and 3) the PlGF/sFlt-1 ratio at 28 to 32 weeks of gestation is abnormal in patients who subsequently delivered due to preterm labor with intact membranes and in those with preterm premature rupture of the membranes if both groups have placental lesions of maternal vascular malperfusion. Such association is not significant in patients with these obstetrical syndromes who do not have placental lesions.

CONCLUSION

Classification of obstetrical syndromes according to the presence or absence of placental lesions of maternal vascular malperfusion allows biomarkers to be informative earlier in gestation and enhances the strength of association between biomarkers and clinical outcomes. We propose that a new taxonomy of obstetrical disorders informed by placental pathology will facilitate the discovery and implementation of biomarkers as well as the prediction and prevention of such disorders.

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.

Placental findings in singleton stillbirths: a case-control study from a tertiary-care center in India

OBJECTIVES

Placental examination in a case of stillbirth can provide insight into causative/associated factors with fetal demise. The aim of this study was to compare placental and umbilical cord pathologies in singleton stillbirth and livebirth placentas, and to find prevalence of various associated maternal and fetal clinical factors.

METHODS

This case-control study was conducted at a tertiary-care center in India over a period of 20 months. About 250 women who delivered stillborn fetus ≥28 weeks' gestation and 250 maternal-age-matched controls were recruited. Sociodemographic and clinical details were noted and placental gross and microscopic examination was done. Placental findings were compared between stillbirth and livebirth (overall), preterm stillbirth and preterm livebirth as well as term stillbirth and term livebirth in six categories - placenta gross, cord gross, membranes gross, maternal vascular malperfusion, fetal vascular malperfusion and inflammatory response. Prevalence of 11 maternal and fetal factors were studied in all categories of placental findings in both livebirth and stillbirth.

RESULTS

Placental findings in all six categories were significantly associated with stillbirths (p<0.05). The placental findings associated with stillbirth with highest odds included placental hypoplasia (OR 9.77, 95% CI 5.46-17.46), necrotizing chorioamnionitis (OR 9.30, 95% CI 1.17-73.96) and avascular villi (OR 8.45, 95% CI 3.53-20.25). More than half of the women with stillbirths had medical disorders (n=130, 52.0%) and the most prevalent was hypertensive disorder (n=45, 18.0%).

CONCLUSIONS

Changes in placenta are associated with development of stillbirth. Therefore, antenatal investigations to identify placental dysfunction should be investigated to determine whether these reduce stillbirth. Also, placental examination in a case of stillbirth can detect/diagnose many maternal/fetal conditions and thereby can help in preventing future stillbirths.

Retrospective analysis of stillbirth and induced termination of pregnancies: Factors affecting determination

OBJECTIVE

The aim of this study was to identify the factors and frequencies of induced termination of pregnancies.

MATERIALS AND METHODS

This is a retrospective study of 488 terminations of pregnancies (TOPs) between January 2011 and December 2021 to demonstrate the factors affecting the decision to terminate the pregnancy. All cases had been hospitalized to manage the induction of labor. Methods included serial multiple laminaria dilation of the cervix and administration of a cervical misoprostol suppository. After induction of labor, the subject may experience amniotomy, instrumental evacuation of the uterus, and even hysterotomy. Pre-procedure counseling included an agreement to share medical records (paper-based and electronic). We verified the indications for all patients seeking TOPs. All cases were performed according to known diagnostic classifications and divided into seven groups for analysis.

RESULTS

The patient ages ranged from 12 to 46 years. The median maternal age was 34 years [interquartile range (IQR) 30, 37]; 52.2% had at least one prior delivery. The pre-procedure diagnosis was divided into seven groups including the following: chromosomal and genetic abnormalities (146/488, 29.9%), no intrauterine heartbeats (126/488, 25.8%), structural anomalies (84/488, 17.2%), elective termination (56/488, 11.5%), preterm premature rupture of membranes (PPROM) (42/488, 8.6%), cervical incompetence (32/488, 6.6%), and other conditions (2/488, 0.4%). After excluding elective terminations, the eleven-year rate of fetal death and stillbirth to births did not show significant changes from 2011 to 2021.

CONCLUSIONS

Knowing the factors underlying the decision to induce intrauterine fetal death (IUFD) including reasons for objecting to pregnancy are important for obstetricians-they can offer better planning and medical counseling. It is important to educate all women about family planning to prevent large numbers of unwanted and unsafe pregnancy terminations.

Placental pathology of resuscitated apparent stillbirth

Resuscitated apparent stillbirth (RAS) is defined as an infant with APGAR scores of 0 at 1 minute of life who receives successful resuscitation. Assessment of placental pathology is considered standard of care in such infants, but the clinical significance of these placental findings as they relate to clinical outcomes has yet to be described within the literature. We report the findings of a retrospective study of placental pathology as defined by the Amsterdam and Dublin criteria of RAS infants born in South Australia over an 8-year period. The aim of this study was to assess whether placental pathology was able to predict RAS clinical outcomes of death, survival with adverse neurological outcomes, and survival with normal neurological outcomes. The RAS cohort within our study is small, reflecting the low incidence of RAS. Of the 25 RAS subjects 16 survived, five with abnormal neurological outcomes and 11 with normal neurological outcomes. No statistically significant difference was seen between the clinical outcome groups in the incidence of specific macroscopic and microscopic placental findings. No sentinel lesion was seen in any one clinical outcome group. Relevant placental pathology was found in all but one subject validating the role of placental pathology in determination of the aetiology of RAS. The most common finding was maternal vascular malperfusion. Placental pathology in RAS infants remains relevant but is unable to contribute to the matrix of predictive information available to the clinician and family.

Chronic Inflammatory Placental Disorders Associated With Recurrent Adverse Pregnancy Outcome

Chronic inflammatory placental disorders are a group of rare but devastating gestational syndromes associated with adverse pregnancy outcome. This review focuses on three related conditions: villitis of unknown etiology (VUE), chronic histiocytic intervillositis (CHI) and massive perivillous fibrin deposition (MPFD). The hallmark of these disorders is infiltration of the placental architecture by maternal immune cells and disruption of the intervillous space, where gas exchange between the mother and fetus occurs. Currently, they can only be detected through histopathological examination of the placenta after a pregnancy has ended. All three are associated with a significant risk of recurrence in subsequent pregnancies. Villitis of unknown etiology is characterised by a destructive infiltrate of maternal CD8+ T lymphocytes invading into the chorionic villi, combined with activation of fetal villous macrophages. The diagnosis can only be made when an infectious aetiology has been excluded. VUE becomes more common as pregnancy progresses and is frequently seen with normal pregnancy outcome. However, severe early-onset villitis is usually associated with fetal growth restriction and recurrent pregnancy loss. Chronic histiocytic intervillositis is characterised by excessive accumulation of maternal CD68+ histiocytes in the intervillous space. It is associated with a wide spectrum of adverse pregnancy outcomes including high rates of first-trimester miscarriage, severe fetal growth restriction and late intrauterine fetal death. Intervillous histiocytes can also accumulate due to infection, including SARS-CoV-2, although this infection-induced intervillositis does not appear to recur. As with VUE, the diagnosis of CHI requires exclusion of an infectious cause. Women with recurrent CHI and their families are predisposed to autoimmune diseases, suggesting CHI may have an alloimmune pathology. This observation has driven attempts to prevent CHI with a wide range of maternal immunosuppression. Massive perivillous fibrin deposition is diagnosed when >25% of the intervillous space is occupied by fibrin, and is associated with fetal growth restriction and late intrauterine fetal death. Although not an inflammatory disorder per se, MPFD is frequently seen in association with both VUE and CHI. This review summarises current understanding of the prevalence, diagnostic features, clinical consequences, immune pathology and potential prophylaxis against recurrence in these three chronic inflammatory placental syndromes.

Stillbirth after COVID-19 in Unvaccinated Mothers Can Result from SARS-CoV-2 Placentitis, Placental Insufficiency, and Hypoxic Ischemic Fetal Demise, Not Direct Fetal Infection: Potential Role of Maternal Vaccination in Pregnancy

Stillbirth is a recently recognized complication of COVID-19 in pregnant women. Other congenitally transmitted infections from viruses, bacteria and parasites can cause stillbirth by infecting fetal organs following transplacental transmission of the agent from the maternal bloodstream. However, recent research on pregnant women with COVID-19 having stillbirths indicates that there is another mechanism of stillbirth that can occur in placentas infected with SARS-CoV-2. In these cases, viral infection of the placenta results in SARS-CoV-2 placentitis, a combination of concurrent destructive findings that include increased fibrin deposition which typically reaches the level of massive perivillous fibrin deposition, chronic histiocytic intervillositis and trophoblast necrosis. These three pathological lesions, in some cases together with placental hemorrhage, thrombohematomas and villitis, result in severe and diffuse placental parenchymal destruction. This pathology can involve greater than one-half of the placental volume, averaging 77% in the largest study of 68 cases, effectively rendering the placenta incapable of performing its function of oxygenating the fetus. This destructive placental process can lead to stillbirth and neonatal death via malperfusion and placental insufficiency which is independent of fetal infection. Fetal autopsies show no evidence that direct infection of fetal organs is contributory. Because all mothers examined have been unvaccinated, maternal vaccination may prevent viremia and consequent placental infection.

Third trimester intrauterine fetal death: proposal for the assessment of the chronology of umbilical cord and placental thrombosis

The timing of umbilical cord and placental thrombosis in the third trimester intrauterine fetal death (TT-IUFD) may be fundamental for medico-legal purposes, when it undergoes medical litigation due to the absence of risk factors. Authors apply to human TT-IUFD cases a protocol, which includes histochemistry and immunohistochemistry (IHC) for the assessment of thrombi’s chronology. A total of 35 thrombi of umbilical cord and/or placenta were assessed: 2 in umbilical artery, 6 in umbilical vein, 15 in insertion, 10 in chorionic vessels, 1 in fetal renal vein, 1 in fetal brachiocephalic vein. Thrombi’s features were evaluated with hematoxylin–eosin, Picro-Mallory, Von Kossa, Perls, and immunohistochemistry for CD15, CD68, CD31, CD61, and Smooth Muscle Actin. The estimation of the age of the thrombi was established by applying neutrophils/macrophages ratio taking into consideration, according to literature, the presence of hemosiderophagi, calcium deposition, and angiogenesis. To estimate an approximate age of fresh thrombi (< 1 day), a non-linear regression model was tested. Results were compared to maternal risk factors, fetal time of death estimated at autopsy, mechanism, and cause of death. Our study confirms that the maternal risk factors for fetal intrauterine death and the pathologies of the cord, followed by those of the placental parenchyma, are the conditions that are most frequently associated with the presence of thrombi. Results obtained with histological stainings document that the neutrophile/macrophage ratio is a useful tool for determining placental thrombi’s age. Age estimation of thrombi on the first day is very challenging; therefore, the study presented suggests the N/M ratio as a parameter to be used, together with others, i.e., hemosiderophagi, calcium deposition, and angiogenesis, for thrombi’s age determination, and hypothesizes that its usefulness regards particularly the first days when all other parameters are negative.

Placental Tissue Destruction and Insufficiency from COVID-19 Causes Stillbirth and Neonatal Death from Hypoxic-Ischemic Injury: A Study of 68 Cases with SARS-CoV-2 Placentitis from 12 Countries

CONTEXT.—

Perinatal death is an increasingly important problem as the COVID-19 pandemic continues, but the mechanism of death has been unclear.

OBJECTIVE.—

To evaluate the role of the placenta in causing stillbirth and neonatal death following maternal infection with COVID-19 and confirmed placental positivity for SARS-CoV-2.

DESIGN.—

Case-based retrospective clinico-pathological analysis by a multinational group of 44 perinatal specialists from 12 countries of placental and autopsy pathology findings from 64 stillborns and 4 neonatal deaths having placentas testing positive for SARS-CoV-2 following delivery to mothers with COVID-19.

RESULTS.—

All 68 placentas had increased fibrin deposition and villous trophoblast necrosis and 66 had chronic histiocytic intervillositis, the three findings constituting SARS-CoV-2 placentitis. Sixty-three placentas had massive perivillous fibrin deposition. Severe destructive placental disease from SARS-CoV-2 placentitis averaged 77.7% tissue involvement. Other findings included multiple intervillous thrombi (37%; 25/68) and chronic villitis (32%; 22/68). The majority (19, 63%) of the 30 autopsies revealed no significant fetal abnormalities except for intrauterine hypoxia and asphyxia. Among all 68 cases, SARS-CoV-2 was detected from a body specimen in 16 of 28 cases tested, most frequently from nasopharyngeal swabs. Four autopsied stillborns had SARS-CoV-2 identified in internal organs.

CONCLUSIONS.—

The pathology abnormalities composing SARS-CoV-2 placentitis cause widespread and severe placental destruction resulting in placental malperfusion and insufficiency. In these cases, intrauterine and perinatal death likely results directly from placental insufficiency and fetal hypoxic-ischemic injury. There was no evidence that SARS-CoV-2 involvement of the fetus had a role in causing these deaths.

HIV, Placental Lesions, and Adverse Perinatal Outcomes

Africa has the highest number of pregnant women with human immunodeficiency virus (HIV). In some studies, HIV has been associated with adverse perinatal outcomes. However, the pathophysiological mechanism leading to adverse fetal outcomes is not known. Maternal vascular malformation, chorioamnionitis, and decreased placental weight have been described as placental features associated with HIV in some studies. The use of antiretroviral therapy has reduced perinatal transmission of HIV and adverse fetal outcomes. However, placental mechanisms associated with HIV and the fetal immune response to maternal HIV infection are poorly understood. Additional research is required to understand whether altered maternal immunity in women living with HIV can trigger fetal responses leading to stillbirth or preterm birth.

Maternal and fetal vascular lesions of malperfusion in the placentas associated with fetal and neonatal death: results of a prospective observational study

BACKGROUND

Fetal death is one of the major adverse pregnancy outcomes and is common in low- and middle-income countries. Placental lesions may play an important role in the etiology of fetal and neonatal deaths. Previous research relating placental lesions to fetal death causation was hindered by a lack of agreement on a placental classification scheme. The Amsterdam consensus statement that was published in 2016 focused its attention on malperfusions in the maternal and fetal placental circulations.

OBJECTIVE

This study aimed to investigate the relationships of placental maternal and fetal vascular malperfusions in fetal and neonatal deaths, focusing on the most important maternal clinical conditions in the pathway to fetal and neonatal deaths, such as maternal hypertension, antepartum hemorrhage, and decreased fetal growth.

STUDY DESIGN

This was a prospective, observational cohort study conducted at 2 Asian sites. The data collected included clinical history, gross and histologic evaluations of the placenta, and several other investigations and were used to determine the cause of death. The placenta was evaluated at both sites using the Amsterdam consensus framework. We estimated the risk of placental maternal and fetal vascular malperfusions in fetal and neonatal deaths.

RESULTS

Between July 2018 and January 2020 in India and Pakistan, 1633 women with placentas available for the study provided consent. Of these women, 814 had fetal deaths, 618 had preterm live births and subsequent neonatal deaths, and 201 had term live births. The prevalence of maternal vascular malperfusion was higher in the placentas associated with fetal deaths (58.4%) and preterm neonatal deaths (31.1%) than in the placentas associated with term live births (15.4%). Adjusting for site, maternal vascular malperfusion had a relative risk of 3.88 (95% confidence interval, 2.70-5.59) in fetal deaths vs term live births and a relative risk of 2.07 (95% confidence interval, 1.41-3.02) in preterm neonatal deaths vs term live births. Infarcts and distal villous hypoplasia were the most common histologic components of maternal vascular malperfusion. Compared with maternal vascular malperfusion (58.4%), fetal vascular malperfusion was less common in the placentas associated with fetal deaths (19.0%). However, there were higher frequencies of fetal vascular malperfusion in the placentas associated with fetal deaths (19.0%) than in placentas associated with neonatal deaths (8.3%) or term live birth (5.0%). Adjusting for site, fetal vascular malperfusion had a relative risk of 4.09 (95% confidence interval, 2.15-7.75) in fetal deaths vs term live births and a relative risk of 1.77 (95% confidence interval, 0.90-3.49) in preterm neonatal deaths vs term live births. Furthermore, there was a higher incidence of maternal vascular malperfusion in cases of maternal hypertension (71.4%), small for gestational age (69.9%), and antepartum hemorrhage (59.1%) than in cases of fetal deaths with none of these conditions (43.3%). There was no significant difference in the occurrence of fetal vascular malperfusion in the 4 clinical categories.

CONCLUSION

Histologic examination of the placenta, especially for malperfusion disorders, is crucial in elucidating pathways to fetal and neonatal deaths in preterm infants. In particular, focusing on placental maternal and fetal vascular malperfusions during pregnancy is a means to identify fetuses at risk of fetal death and is an important strategy to reduce the risk of fetal death early delivery. We hope that the increased risk of fetal and neonatal deaths in these pregnancies can be reduced by the development of an intervention that reduces the likelihood of developing maternal and fetal vascular malperfusion.

Obstetric Outcomes in the Surviving Fetus after Intrauterine Fetal Death in Bichorionic Twin Gestations

Twin pregnancies are high-risk gestations that increase the odds of obstetrical complications. They can also present specific and rare complications such as single intrauterine fetal death (IUFD). This complication has been extensively studied in monochorionic but not in bichorionic gestations. Today, the repercussions of IUFD may have on the surviving fetus, mother and bichorionic pregnancy are not known. Our objective was to study materno-obstetrical, fetal, and immediate delivery neonatal complications in bichorionic twin gestations with single IUFD compared to those with both fetuses alive. A retrospective and observational case-control study was performed in bichorionic biamniotic twin pregnancies, 22 complicated with single IUFD after 14 weeks (cases; IUFD group) and 51 with both fetuses alive (controls; non-IUFD group, from Obstetrics Service of La Paz Hospital (Madrid, Spain). The data were collected from obstetrical records. No significant differences were found in the rates of gestational diabetes, gestational hypertension, preeclampsia, neonatal complications, and prematurity between IUFD and non-IUFD groups. Statistical differences were found for the incidence of intrauterine growth restriction in the surviving fetus compared to first fetus of pregnancy with both fetuses alive (22.7% versus 2.0%, respectively; p-value = 0.012). There were no differences compared to second fetus (11.8%; p-value = 0.23). There was a high C-section rate in both groups (IUFD = 63.6%, non-IUFD = 64.7%; p-value = 0.19). In conclusion, single IUFD in bichorionic biamniotic twin gestations is a rare complication that should be closely monitored. It is essential that these gestations be attended by a clinical multidisciplinary team.

Fetal akinesia deformation sequence and massive perivillous fibrin deposition resulting in fetal death in six fetuses from one consanguineous couple, including literature review

Background

Massive perivillous fibrin deposition (MPFD) is associated with adverse pregnancy outcomes and is mainly caused by maternal factors with limited involvement of fetal or genetic causes. We present one consanguineous couple with six fetuses developing Fetal Akinesia Deformation Sequence (FADS) and MPFD, with a possible underlying genetic cause. This prompted a literature review on prevalence of FADS and MPFD.

Methods

Fetal ultrasound examination, motor assessment, genetic testing, postmortem examination, and placenta histology are presented (2009–2019). Literature was reviewed for the association between congenital anomalies and MPFD.

Results

All six fetuses developed normally during the first trimester. Thereafter, growth restriction, persistent flexed position, abnormal motility, and contractures in 4/6, consistent with FADS occurred. All placentas showed histologically confirmed MPFD. Genetic analyses in the five available cases showed homozygosity for two variants of unknown significance in two genes, VARS1 (OMIM*192150) and ABCF1 (OMIM*603429). Both parents are heterozygous for these variants. From 63/1999 manuscripts, 403 fetal outcomes were mobilized. In 14/403 fetuses, congenital abnormalities in association with MPFD were seen of which two fetuses with contractures/FADS facial anomalies.

Conclusion

The low prevalence of fetal contractures/FADS facial anomalies in association with MPFD in the literature review supports the possible fetal or genetic contribution causing FADS and MPFD in our family. This study with literature review supports the finding that fetal, fetoplacental, and/or genetic components may play a role in causing a part of MPFDs.

COVID-19 and fertility-at the crossroads of autoimmunity and thrombosis

The SARS-CoV-2 virus is known to mediate attack via ACE-2 Receptor, thus having adverse effects on cardiovascular, respiratory, digestive and reproductive systems, the latter being an area of emerging concern, due to the associated impact on fertility, with potential for an outsized effect on population distribution and socioeconomic road map in subsequent years. This narrative review aims to put forth the current evidence of effect of SARS-CoV-2 on human fertility from a multipronged immunologic, haematologic, and gynaecologic perspective; highlighting the areas of contradiction and potential future measures. A literature search was conducted through the MEDLINE and SCOPUS databases to identify articles on the subject in English. Relevant information was extracted from around 300 articles for this review. The existing data give non-conclusive evidence about the impact of SARS-CoV-2 infection on fertility; however, a greater impact on male fertility as compared to females merits further exploration. However, reproduction and fertility is a key concern and considering the pandemic is prolonged, natural conception or ART require extra precautions.

Wave reflections in the umbilical artery measured by Doppler ultrasound as a novel predictor of placental pathology

Background

The umbilical artery (UA) Doppler pulsatility index is used clinically to detect elevated feto-placental vascular resistance. However, this metric is confounded by variation in fetal cardiac function and is only moderately predictive of placental pathology. Our group developed a novel ultrasound methodology that measures wave reflections in the UA, thereby isolating a component of the Doppler signal that is specific to the placenta. The present study examined whether wave reflections in the UA are predictive of placental vascular pathology.

Methods

Standard clinical Doppler ultrasound of the UAs was performed in 241 pregnant women. Of these, 40 women met narrowly defined preset criteria for the control group, 36 had maternal vascular malperfusion (MVM) and 16 had fetal vascular malperfusion (FVM). Using a computational procedure, the Doppler waveforms were decomposed into a pair of forward and backward propagating waves.

Findings

Compared to controls, wave reflections were significantly elevated in women with either MVM (p<0.0001) or FVM pathology (p = 0.02). In contrast, the umbilical and uterine artery pulsatility indices were only elevated in the MVM group (p<0.0001) and there were no differences between women with FVM and the controls.

Interpretation

The measurement of wave reflections in the UA, combined with standard clinical ultrasound parameters, has the potential to improve the diagnostic performance of UA Doppler to detect placental vascular pathology. Identifying women with FVM pathology is particularly challenging prenatally and future investigations will determine if women at risk of this specific placental disease could benefit from this novel diagnostic technique.

One-Sided Chronic Intervillositis of Unknown Etiology in Dizygotic Twins: A Description of 3 Cases

Chronic intervillositis of unknown etiology (CIUE) is a rare, poorly understood, histopathological diagnosis of the placenta that is frequently accompanied by adverse pregnancy outcomes including miscarriage, fetal growth restriction, and intrauterine fetal death. CIUE is thought to have an immunologically driven pathophysiology and may be related to human leukocyte antigen mismatches between the mother and the fetus. Dizygotic twins with one-sided CIUE provide an interesting context to study the influence of immunogenetic differences in such cases. The main immune-cell subsets were investigated using immunohistochemistry. We identified three dizygotic twin pregnancies in which CIUE was present in only one of the two placentas. Two of the pregnancies ended in term delivery and one ended in preterm delivery. Presence of CIUE was correlated with lower placental weight and lower birthweight. Relative number of CD68, CD56, CD20, and CD3 positive cells were comparable between co-twins. The presence of one-sided CIUE in dizygotic twin pregnancy was associated with selective growth restriction in the affected twin. This suggests a unique fetal immunogenetic contribution to the pathogenesis of CIUE. Further study of dizygotic and monozygotic placentas affected by CIUE could identify new insights into its pathophysiology and into the field of reproductive immunology.

Chronic histiocytic intervillositis: A breakdown in immune tolerance comparable to allograft rejection?

Chronic histiocytic intervillositis (CHI) is a pregnancy disorder characterized by infiltration of maternal macrophages into the intervillous space of the human placenta, often with accompanying perivillous fibrin deposition. CHI is associated strongly with foetal growth restriction and increased risk of miscarriage and stillbirth. Although rare, affecting 6 in every 10 000 pregnancies beyond 12 weeks' gestation, the rate of recurrence is high at 25%-100%. To date, diagnosis of CHI can only be made post-delivery upon examination of the placenta due to a lack of diagnostic biomarkers, and criteria vary across publications. No treatment options have shown proven efficacy, and CHI remains a serious obstetric conundrum. Although its underlying aetiology is unclear, due to the presence of maternal macrophages and the reported increased incidence in women with autoimmune disease, CHI is hypothesized to be an inappropriate immune response to the semi-allogeneic foetus. Given this lack of understanding, treatment approaches remain experimental with limited rationale. However, there is recent evidence that immunosuppression and antithrombotic therapies may be effective in preventing recurrence of associated adverse pregnancy outcomes. With similarities noted between the pathological features of CHI and acute rejection of solid organ transplants, further investigation of this hypothesis may provide a basis for tackling CHI and other immune-related placental conditions. This review will explore parallels between CHI and allograft rejection and identify areas requiring further confirmation and exploitation of this comparison.

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.

Formulating a Meaningful and Comprehensive Placental Phenotypic Classification

INTRODUCTION

While many placental lesions have been identified and defined, the significance of multiple overlapping lesions has not been addressed. The purpose of our analysis was to evaluate overlapping patterns of placental pathology and determine meaningful phenotypes associated with adverse birth outcomes.

METHODS

Placental pathology reports were obtained from a single hospital between 2009 and 2018. Placental lesions were grouped into four major categories: acute inflammation (AI), chronic inflammation (CI), maternal vascular malperfusion (MVM), and fetal vascular malperfusion (FVM). Within each category, lesions were classified as not present, low grade or high grade. Combinations of pathologies were evaluated in relation to preterm birth (<37 weeks) and small for gestational age (SGA) infant (birthweight <10th percentile).

RESULTS

During the study period, 19,027 placentas were reviewed by pathologists. Results from interaction models indicate that MVM and MVM in combination with CI and/or FVM are associated with the greatest odds of SGA infant and PTB. When incorporating grade, we identified 21 phenotype groups, each with characteristic associations with the SGA infant and patterns of PTB.

DISCUSSION

We have developed a comprehensive and meaningful placental phenotype that incorporates severity and multiplicity of placental lesions. We have also developed a web application to facilitate phenotype determination (https://placentaexpression.shinyapps.io/phenotype).

Placental pathology and maternal factors associated with stillbirth: An institutional based case-control study in Northern Tanzania

OBJECTIVE

To determine the placental pathologies and maternal factors associated with stillbirth at Kilimanjaro Christian Medical Centre, a tertiary referral hospital in Northern Tanzania.

METHODS

A 1:2 unmatched case-control study was carried out among deliveries over an 8-month period. Stillbirths were a case group and live births were the control group. Respective placentas of the newborns from both groups were histopathologically analyzed. Maternal information was collected via chart review. Mean and standard deviation were used to summarize the numerical variables while frequency and percentage were used to summarize categorical variables. Crude and adjusted logistic regressions were done to test the association between each variable and the risk of stillbirth.

RESULTS

A total of 2305 women delivered during the study period. Their mean age was 30 ± 5.9 years. Of all deliveries, 2207 (95.8%) were live births while 98 (4.2%) were stillbirths. Of these, 96 stillbirths (cases) and 192 live births (controls) were enrolled. The average gestational age for the enrolled cases was 33.8 ±3.2 weeks while that of the controls was 36.3±3.6 weeks, (p-value 0.244). Of all stillbirths, nearly two thirds 61(63.5%) were males while the females were 35(36.5%). Of the stillbirth, 41were fresh stillbirths while 55 were macerated. The risk of stillbirth was significantly associated with lower maternal education [aOR (95% CI): 5.22(2.01-13.58)], history of stillbirth [aOR (95%CI): 3.17(1.20-8.36)], lower number of antenatal visits [aOR (95%CI): 6.68(2.71-16.48), pre/eclampsia [aOR (95%CI): 4.06(2.03-8.13)], and ante partum haemorrhage [OR (95%CI): 2.39(1.04-5.53)]. Placental pathology associated with stillbirth included utero-placental vascular pathology and acute chorioamnionitis.

CONCLUSIONS

Educating the mothers on the importance of regular antenatal clinic attendance, monitoring and managing maternal conditions during antenatal periods should be emphasized. Placentas from stillbirths should be histo-pathologically evaluated to better understand the possible aetiology of stillbirths.

A structured review of placental morphology and histopathological lesions associated with SARS-CoV-2 infection

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel coronavirus, was first identified after a cluster of cases in Wuhan, China in December 2019. Whether vertical transmission or placental pathology might occur following maternal infection during pregnancy remains unknown. This review aimed to summarise all studies that examined the placenta or neonates following infection with SARS-CoV-2, or closely related highly pathogenic coronavirus (SARS-CoV-1, or the Middle East respiratory syndrome coronavirus (MERS-CoV)). Structured literature searches found 50 studies that met the inclusion criteria. Twenty studies reported placental histopathology findings in third trimester placentas following maternal SARS-CoV-2 infection. Using the Amsterdam Consensus criteria to categorise the histopathology results, evidence of both fetal vascular malperfusion (35.3% of cases; 95% Confidence Interval (CI) 27.7-43.0%) and maternal vascular malperfusion (46% of cases; 95% CI 38.0-54.0%) were reported, along with evidence of inflammation in the placentas (villitis 8.7% cases, intervillositis 5.3% of cases, chorioamnionitis 6% of cases). The placental pathologies observed in SARS-CoV-2 were consistent with findings following maternal SARS-CoV-1 infection. Of those tested, a minority of neonates (2%) and placental samples tested positive for SARS-CoV-2 infection (21%). Limited conclusions can be drawn about the effect of maternal SARS-CoV-2 infection on placental pathology as most lack control groups and the majority of reports followed third trimester infection. Collaboration to maximise the number of samples examined will increase the reliability and generalisability of findings. A better understanding of the association between maternal SARS-CoV-2 infection and placental pathology will inform maternity care during the coronavirus pandemic.

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.