Confirming Vertical Fetal Infection With Coronavirus Disease 2019: Neonatal and Pathology Criteria for Early Onset and Transplacental Transmission of Severe Acute Respiratory Syndrome Coronavirus 2 From Infected Pregnant Mothers

Transplacental Transmission of SARS-CoV-2: A Narrative Review

Background and Objectives: The study aims to explore the potential for transplacental transmission of SARS-CoV-2, focusing on its pathophysiology, placental defense mechanisms, and the clinical implications for maternal and neonatal health. Materials and Methods: A comprehensive review of the current literature was conducted, analyzing studies on SARS-CoV-2 infection in pregnancy, the expression of key viral receptors (ACE2 and TMPRSS2) in placental cells, and the immune responses involved in placental defense. The review also examined the clinical outcomes related to maternal and neonatal health, including adverse pregnancy outcomes and neonatal infection. Results: The expression of ACE2 and TMPRSS2 in the placenta supports the biological plausibility of SARS-CoV-2 transplacental transmission. Histopathological findings from the infected placentas reveal inflammation, vascular changes, and the evidence of viral particles in placental tissues. Clinical reports indicate an increased risk of preterm birth, intrauterine growth restriction, and neonatal infection in pregnancies affected by COVID-19. However, the frequency and mechanisms of vertical transmission remain variable across studies, highlighting the need for standardized research protocols. Conclusions: SARS-CoV-2 can potentially infect placental cells, leading to adverse pregnancy outcomes and neonatal infection. While evidence of transplacental transmission has been documented, the risk and mechanisms are not fully understood. Ongoing research is essential to clarify these aspects and inform obstetric care practices to improve maternal and neonatal outcomes during the COVID-19 pandemic.

SARS-CoV-2 Infection during Delivery Causes Histopathological Changes in the Placenta

BACKGROUND

SARS-CoV-2 can damage human placentas, leading to pregnancy complications, such as preeclampsia and premature birth. This study investigates the histopathological changes found in COVID-19-affected placentas.

MATERIALS AND METHODS

This study included 23 placentas from patients with active COVID-19 during delivery and 22 samples from patients without COVID-19 infection in their medical history. The samples underwent histopathological examination for pathology, such as trophoblast necrosis, signs of vessel damage, or fetal vascular malperfusion.

RESULTS

Newborns from the research group have lower weights and Apgar scores than healthy newborns. In the COVID-19 group, calcifications and collapsed intervillous space were more frequent, and inflammation was more severe than in the healthy group. At the same time, the placenta of SARS-CoV-2-positive patients showed signs of accelerated vascular maturation. Trophoblast necrosis was found only in the placentas of the research group. The expression of CD68+ was elevated in the COVID-19 cohort, suggesting that macrophages constituted a significant part of the inflammatory infiltrate. The increase in lymphocyte B markers was associated with placental infarctions, while high levels of CD3+, specific for cytotoxic T lymphocytes, correlated with vascular injury.

CONCLUSIONS

SARS-CoV-2 is associated with pathological changes in the placenta, including trophoblast necrosis, calcification, and accelerated villous maturation. Those changes appear to be driven by T cells and macrophages, whose increased expression reflects ongoing histiocytic intervillositis in the placenta.

Association between maternal and perinatal outcomes and histological changes in the placenta of patients with Covid-19: A cohort study

Although studies evaluated placental involvement in Covid-19 patients, few have assessed its association with clinical repercussions. The study aimed to determine the association between the clinical status and maternal and perinatal outcomes of patients with Covid-19 at delivery and changes in placental histology. It is so far the largest cohort evaluating placentas of patients infected by the SARS-CoV-2. A secondary analysis was conducted of a database from which a cohort of 226 patients, who tested real-time polymerase chain reaction-positive for Covid-19 at delivery and whose placentas were collected and submitted to pathology, was selected for inclusion. One or more types of histological changes were detected in 44.7% of the 226 placentas evaluated. The most common abnormalities were maternal vascular malperfusion (38%), evidence of inflammation/infection (9.3%), fetal vascular malperfusion (0.8%), fibrinoid changes and intervillous thrombi (0.4%). Oxygen use (P = .01) and need for admission to an intensive care unit (ICU) (P = .04) were less common in patients with placental findings, and hospital stay was shorter in these patients (P = .04). There were more fetal deaths among patients with evidence of inflammation/infection (P = .02). Fetal death, albeit uncommon, is associated with findings of inflammation/infection. Oxygen use and need for admission to an ICU were less common among patients with placental findings, probably due to the pregnancy being interrupted early. None of the other findings was associated with maternal clinical status or with adverse perinatal outcome.

Intrauterine fetal death in a COVID positive pregnant woman

SARS-CoV-2 disease mechanisms are not yet fully understood, especially in cases affecting pregnant women. In fact, although they suffer from the same symptoms as non-pregnant women, they are more susceptible to-adverse outcomes of COVID-19 as well as pregnancy complications leading to stillbirth, premature rupture of membrane, or intrauterine fetal demise (IUFD). The consequences on pregnancy are not clearly correlated with the severity of the infection. We present a case of fetal death in a 30-year-old woman with a confirmed SARS-CoV-2 infection without any other significant clinical or obstetric disorders. A histopathological examination of the placenta indicated massive and diffuse intervillar fibrinoid deposits associated with chronic histiocytic intervillositis that can be associated with SARS-CoV-2 placentitis. Given the high rates of SARS-CoV-2 infections in pregnancy, it is important to understand the factors that determine negative pregnancy outcomes, regardless of the severity of the patient's symptoms.

Effects of permanent placental injury due to severe acute respiratory syndrome coronavirus 2 infection during pregnancy on the feto-placental circulation: a cross-sectional study

OBJECTIVE

The aim of this study was to evaluate the effects of permanent placental injury due to a severe acute respiratory syndrome coronavirus 2 infection during pregnancy on feto-placental circulation.

METHODS

In this cross-sectional study, 83 pregnant women with planned deliveries were divided into two groups according to their severe acute respiratory syndrome coronavirus 2 infection statuses during pregnancy. Their demographic parameters, obstetric histories, and prenatal risks were evaluated. A prenatal fetal Doppler ultrasound examination was performed for all participants, and umbilical artery and middle cerebral artery Doppler parameters were obtained. Postpartum placentas were examined for pathological findings under appropriate conditions. All placentas were evaluated according to the Amsterdam consensus criteria. Mann-Whitney U test, Student's t-test, and chi-square test were used for comparisons.

RESULTS

Demographic parameters were statistically similar, except that they were borderline significant for gestational weeks at delivery (p=0.044). In the pathological examination of the placenta, regardless of the trimester of exposure to viral infection, perivillous fibrin deposition and villus dystrophic calcification were more common in group 2 (p=0.016 and p=0.048, respectively) than in group 1. In the prenatal Doppler examination between the groups, no statistically significant difference was found for all of the umbilical artery pulsatile index, middle cerebral artery pulsatile index, and cerebro-placental ratio values.

CONCLUSION

Severe acute respiratory syndrome coronavirus 2 infection during pregnancy causes an increase in perivillous fibrin deposition and villus dystrophic calcification in the placenta. Placental injury caused by the severe acute respiratory syndrome coronavirus 2 virus does not affect fetal Doppler parameters.

Clinical Features of SARS-CoV-2 Infection During Pregnancy and Associated Placental Pathologies

SUMMARY

We reviewed the clinicopathologic findings of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-exposed placentas at our institution. We identified patients diagnosed with SARS-CoV-2 during pregnancy (March-October 2020). Clinical data included gestational age at diagnosis and delivery and maternal symptoms. Hematoxylin and eosin slides were reviewed for maternal vascular malperfusion, fetal vascular malperfusion, chronic villitis, amniotic fluid infection, intervillous thrombi, fibrin deposition, and infarction. Immunohistochemistry (IHC) for coronavirus spike protein and RNA in situ hybridization (ISH) for SARS-CoV-2 was performed on a subset of blocks. A review of placentas from age-matched patients received March-October 2019 was conducted as a comparison cohort. A total of 151 patients were identified. Placentas in the 2 groups were similar in weight for gestational age and had similar rates of maternal vascular malperfusion, fetal vascular malperfusion, amniotic fluid infection, intervillous thrombi, fibrin deposition, and infarction. Chronic villitis was the only significantly different pathologic finding between cases and controls (29% of cases showed chronic villitis vs. 8% of controls, P <0.001). Overall, 146/151 (96.7%) cases were negative for IHC and 129/133 (97%) cases were negative for RNA ISH. There were 4 cases that stained positively for IHC/ISH, 2 of which showed massive perivillous fibrin deposition, inflammation, and decidual arteriopathy. Coronavirus disease 2019 (COVID-19)-positive patients were more likely to self-identify as Hispanic and more likely to have public health insurance. Our data suggests SARS-CoV-2 exposed placentas that stain positively for SARS-CoV-2 show abnormal fibrin deposition, inflammatory changes, and decidual arteriopathy. The group of patients with clinical COVID-19 are more likely to show chronic villitis. IHC and ISH evidence of viral infection is rare.

Mechanisms of SARS-CoV-2 Placental Transmission

The widespread occurrence of SARS-CoV-2 infections and the diverse range of symptoms have placed significant strain on healthcare systems worldwide. Pregnancy has also been affected by COVID-19, with an increased risk of complications and unfavorable outcomes for expectant mothers. Multiple studies indicate that SARS-CoV-2 can infiltrate the placenta, breach its protective barrier, and infect the fetus. Although the precise mechanisms of intrauterine transmission remain unclear, factors such as perinatal infection, macrophages, sexual intercourse, and the virus' interaction with host angiotensin-converting enzyme 2 (ACE2) and neuropilin-1 (NRP-1) proteins appear to play a role in this process. The integrity of the placental barrier fluctuates throughout pregnancy and appears to influence the likelihood of fetal transmission. The expression of placental cell receptors, like ACE2, changes during pregnancy and in response to placental damage. However, due to the consistent presence of others, such as NRP-1, SARS-CoV-2 may potentially enter the fetus at different stages of pregnancy. NRP-1 is also found in macrophages, implicating maternal macrophages and Hofbauer cells as potential routes for viral transmission. Our current understanding of SARS-CoV-2's vertical transmission pathways remains limited. Some researchers question the ACE2-associated transmission model due to the relatively low expression of ACE2 in the placenta. Existing studies investigating perinatal transmission and the impact of sexual intercourse have either involved small sample sizes or lacked statistical significance. This review aims to explore the current state of knowledge regarding the potential mechanisms of COVID-19 vertical transmission, identifying areas where further research is needed to fill the gaps in our understanding.

Midwifery care for a COVID-19 cohort of women in Northern Italy: two years of pandemic

BACKGROUND

The rapid development of the COVID-19 pandemic has altered the context of healthcare around the world. SARS-CoV-2 positive pregnant and postnatal women, being at greater risk of complications, require continuous midwifery surveillance as well as specialized medical care. Scientific literature lacks studies related to midwifery care models in hospital settings during the pandemic. The aim of this work is to describe hospitalizations in an obstetric-gynecological COVID care unit and to provide a descriptive analysis of the organizational and care model adopted.

METHODS

A cohort retrospective descriptive study was carried out. The sample was stratified by COVID-related care complexity and by obstetric risk. The sample recruited pregnant women, postnatal women, and gynecological patients with confirmed SARS-CoV-2 infection admitted to the obstetric-gynecological COVID unit of a birth center in Northern Italy, from March 16, 2020, to March 16, 2022.

RESULTS

A number of 1037 women were hospitalized, and of these, 551 were SARS-CoV-2 positive women. The 551 SARS-CoV-2 positive women included 362 pregnant women, 132 postnatal women, 9 gynecological patients with medical diagnosis while 17 with a surgical path, and 31 women undergoing voluntary interruption of pregnancy. The final sample included 536 women. 68.6% of women requested a low care complexity, 22.8% a medium one, and 8.6% a high care complexity. Among the obstetric women population, the majority (70.6%) showed a high obstetric risk.

CONCLUSIONS

The COVID-19 cohort of women required different levels of care with various care complexity and levels of obstetric risk. The model adopted allowed the acquisition of new technical and professional skills as well as the sharing of responsibilities and competences according to the care model of the Buddy System. Future studies could investigate COVID-related care models adopted internationally, but also deepen the technical and professional skills developed by midwives during the pandemic in order to enrich, improve and support midwifery profession.

SARS-CoV-2 Infection in Late Pregnancy and Childbirth from the Perspective of Perinatal Pathology

This review focuses on SARS-CoV-2 infection in placental and fetal tissues. Viremia is rare in infected pregnant women, and the virus is seldom amplified from placental tissues. Definite and probable placental infection requires the demonstration of viral RNA or proteins using in situ hybridization (ISH) and immunohistochemistry (IHC). Small subsets (1.0-7.9%, median 2.8%) of placentas of SARS-CoV-2-positive women showed definite infection accompanied by a characteristic histopathology named SARS-CoV-2 placentitis (SP). The conventionally accepted histopathological criteria for SP include the triad of intervillositis, perivillous fibrin deposition, and trophoblast necrosis. SP was shown to be independent of the clinical severity of the infection, but associated with stillbirth in cases where destructive lesions affecting more than 75% of the placental tissue resulted in placental insufficiency and severe fetal hypoxic-ischemic injury. An association between maternal thrombophilia and SP was shown in a subset of cases, suggesting a synergy of the infection and deficient coagulation cascade as one of the mechanisms of the pathologic accumulation of fibrin in affected placentas. The virus was amplified from fetal tissues in approximately 40% of SP cases, but definite fetal involvement demonstrated using ISH or IHC is exceptionally rare. The placental pathology in SARS-CoV-2-positive women also includes chronic lesions associated with placental malperfusion in the absence of definite or probable placental infection. The direct viral causation of the vascular malperfusion of the placenta in COVID-19 is debatable, and common predispositions (hypertension, diabetes, and obesity) may play a role.

Histological Alterations in Placentas of Pregnant Women with SARS-CoV-2 Infection: A Single-Center Case Series

This study aimed to investigate the histopathological changes associated with SARS-CoV-2 infection in placentas. A case series of anatomopathological analysis was conducted on the placentas of pregnant women with SARS-CoV-2 who delivered between March and December 2020 at Santo Amaro Hospital (HSA) in Salvador, Brazil. Out of the 29 placentas examined, the median weight was 423.0 (IQR: 385.0-521.0) g. Among them, 58.3% (n = 14) had inadequate weight relative to the newborn's weight. The histopathological findings revealed that 86.2% (n = 25) of the placentas had poorly defined lobes, and the fetal and maternal surface color was normal in 89.7% (n = 26) and 93.1% (n = 27), respectively. Additionally, 51.7% (n = 15) of the umbilical cords displayed hypercoiling. The most frequent microscopic finding was infarction, present in 35.3% (n = 6) of the cases, followed by 11.8% (n = 2) for each of chorioamnionitis, chronic villitis, focal perivillositis, and laminar necrosis. Analysis of the umbilical cords identified 23.5% (n = 4) cases of intervillous thrombosis, while amnion analysis showed 13.8% (n = 4) cases of squamous metaplasia. Extraplacental membrane examination revealed fibrin deposition in 93.1% (n = 27) of the cases, necrosis in 62.0% (n = 18), calcifications in 51.7% (n = 15), cysts in 37.9% (n = 11), neutrophilic exudate in 17.2% (n = 5), thrombosis in 13.7% (n = 4), and delayed placental maturation in 6.9% (n = 2). All analyzed placentas exhibited histopathological changes, primarily vascular and inflammatory, which indicate SARS-CoV-2 infection in term pregnancies. These alterations could be associated with impaired placental function, fetal growth restriction, preeclampsia, and prematurity. However, further prospective studies are required to validate the type, prevalence, and prognosis of each of these changes.

Immune and cytokine alterations and RNA-sequencing analysis in gestational tissues from pregnant women after recovery from COVID-19

BACKGROUND

COVID-19 is a global pandemic. Understanding the immune responses in pregnant women recovering from COVID-19 may suggest new therapeutic approaches.

METHODS

We performed a cross-sectional study between March 1, 2020, and September 1, 2020. Participants were assigned into the convalescent COVID-19 group if they had a previous COVID-19 infection during pregnancy or the healthy control group. RNA-Seq was performed on human umbilical cord mesenchymal stem cells (hUMSCs) and human amniotic mesenchymal stem cells (hAMSCs). Immunohistochemical staining, cytokine testing, lymphocyte subset analysis, RNA-Seq, and functional analyses were performed on the placental and umbilical cord blood (UCB) and compared between the two groups.

RESULTS

A total of 40 pregnant women were enrolled, with 13 in the convalescent group and 27 in the control group. There were 1024, 46, and 32 differentially expressed genes (DEGs) identified in the placental tissue, hUMSCs, and hAMSCs between the convalescent and control groups, respectively. Enrichment analysis showed those DEGs were associated with immune homeostasis, antiviral activity, cell proliferation, and tissue repair. Levels of IL-6, TNF-α, total lymphocyte counts, B lymphocytes, Tregs percentages, and IFN-γ expressing CD4+ and CD8+ T cells were statistically different between two groups (p ≤ 0.05). ACE2 and TMPRSS2 expressed on the placenta were not different between the two groups (p > 0.05).

CONCLUSION

Multiple changes in immune responses occurred in the placental tissue, hUMSCs, and hAMSCs after maternal recovery from COVID-19, which might imply their protective roles against COVID-19 infection.

Mpox Virus in Pregnancy, the Placenta, and Newborn

CONTEXT.—

Before its eradication, the smallpox virus was a significant cause of poor obstetric outcomes, including maternal and fetal morbidity and mortality. The mpox (monkeypox) virus is now the most pathogenic member of the Orthopoxvirus genus infecting humans. The 2022 global mpox outbreak has focused attention on its potential effects during pregnancy.

OBJECTIVE.—

To understand the comparative effects of different poxvirus infections on pregnancy, including mpox virus, variola virus, vaccinia virus, and cowpox virus. The impact on the pregnant individual, fetus, and placenta will be examined, with particular attention to the occurrence of intrauterine vertical transmission and congenital infection.

DATA SOURCES.—

The data are obtained from the authors' cases and from various published sources, including early historical information and contemporary publications.

CONCLUSIONS.—

Smallpox caused maternal and perinatal death, with numerous cases reported of intrauterine transmission. In endemic African countries, mpox has also affected pregnant individuals, with up to a 75% perinatal case fatality rate. Since the start of the 2022 mpox outbreak, increasing numbers of pregnant women have been infected with the virus. A detailed description is given of the congenital mpox syndrome in a stillborn fetus, resulting from maternal-fetal transmission and placental infection, and the potential mechanisms of intrauterine infection are discussed. Other poxviruses, notably vaccinia virus and, in 1 case, cowpox virus, can also cause perinatal infection. Based on the historical evidence of poxvirus infections, mpox remains a threat to the pregnant population, and it can be expected that additional cases will occur in the future.

Congenital SARS-CoV-2 Infection in Two Neonates with Confirmation by Viral Culture of the Placenta in One Case

Congenital infections with SARS-CoV-2 are uncommon. We describe two confirmed congenital SARS-CoV-2 infections using descriptive, epidemiologic and standard laboratory methods and in one case, viral culture. Clinical data were obtained from health records. Nasopharyngeal (NP) specimens, cord blood and placentas when available were tested by reverse transcriptase real-time PCR (RT-PCR). Electron microscopy and histopathological examination with immunostaining for SARS-CoV-2 was conducted on the placentas. For Case 1, placenta, umbilical cord, and cord blood were cultured for SARS-CoV-2 on Vero cells. This neonate was born at 30 weeks, 2 days gestation by vaginal delivery. RT-PCR tests were positive for SARS-CoV-2 from NP swabs and cord blood; NP swab from the mother and placental tissue were positive for SARS-CoV-2. Placental tissue yielded viral plaques with typical morphology for SARS-CoV-2 at 2.8 × 10² pfu/mL confirmed by anti-spike protein immunostaining. Placental examination revealed chronic histiocytic intervillositis with trophoblast necrosis and perivillous fibrin deposition in a subchorionic distribution. Case 2 was born at 36 weeks, 4 days gestation. RT-PCR tests from the mother and infant were all positive for SARS-CoV-2, but placental pathology was normal. Case 1 may be the first described congenital case with SARS-CoV-2 cultivated directly from placental tissue.

Impact of SARS-CoV-2 Infection on Unvaccinated Pregnant Women: Non-Reassuring Fetal Heart Rate Tracing Because of Placentitis

In 2020, a new coronavirus, called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged in China. SARS-CoV-2 infection has been shown to be highly morbid in pregnant women, being a risk factor for several obstetric conditions leading to increased maternal and neonatal mortality. A few studies since 2020 have shown SARS-CoV-2 maternal-fetal transmission and noted placental abnormalities grouped under the term placentitis. We hypothesized that these placental lesions could be responsible for abnormalities in placental exchange and therefore abnormalities in cardiotocographic monitoring, leading to premature fetal extraction. The objective is to identify the clinical, biochemical, and histological determinants associated with the occurrence of non-reassuring fetal heart rate (NRFHR) outside labor in fetuses of SARS-CoV-2-infected mothers. We conducted a retrospective multicenter case series of the natural history of maternal SARS-CoV-2 infections resulting in fetal delivery outside labor due to NRFHR. Collaboration was sought with the maternity hospitals in the CEGORIF, the APHP and Brussels hospitals. The investigators were contacted by e-mail on three successive occasions over a period of one year. Data from 17 mothers and 17 fetuses were analyzed. Most women had a mild SARS-CoV-2 infection; only two women presented severe infection. No woman was vaccinated. We found a substantial proportion of maternal coagulopathy at birth: elevation of APTT ratio (62%), thrombocytopenia (41%) and liver cytolysis (58.3%). Iatrogenic prematurity was noted in 15 of 17 fetuses, and 100% were born by cesarean delivery due to emergency criteria. One male neonate died on the day of birth due to peripartum asphyxia. Three cases of maternal-fetal transmission were recorded following WHO criteria. Placental analysis in 15 cases revealed eight cases of SARS-CoV-2 placentitis, causing placental insufficiency. In total, 100% of the placentas analyzed showed at least one lesion suggestive of placentitis. SARS-CoV-2 maternal infection during pregnancy is likely to generate neonatal morbidity in relation to placental damage resulting in placental insufficiency. This morbidity may be the consequence of induced prematurity as well as acidosis in the most severe situations. Placental damage occurred in unvaccinated women and in women with no identified risk factor, in contrast to severe maternal clinical forms.

Roles of TGF-β1 in Viral Infection during Pregnancy: Research Update and Perspectives

Transforming growth factor-beta 1 (TGF-β1) is a pleiotropic growth factor playing various roles in the human body including cell growth and development. More functions of TGF-β1 have been discovered, especially its roles in viral infection. TGF-β1 is abundant at the maternal-fetal interface during pregnancy and plays an important function in immune tolerance, an essential key factor for pregnancy success. It plays some critical roles in viral infection in pregnancy, such as its effects on the infection and replication of human cytomegalovirus in syncytiotrophoblasts. Interestingly, its role in the enhancement of Zika virus (ZIKV) infection and replication in first-trimester trophoblasts has recently been reported. The above up-to-date findings have opened one of the promising approaches to studying the mechanisms of viral infection during pregnancy with links to corresponding congenital syndromes. In this article, we review our current and recent advances in understanding the roles of TGF-β1 in viral infection. Our discussion focuses on viral infection during pregnancy, especially in the first trimester. We highlight the mutual roles of viral infection and TGF-β1 in specific contexts and possible functions of the Smad pathway in viral infection, with a special note on ZIKV infection. In addition, we discuss promising approaches to performing further studies on this topic.

Transmission of SARS-CoV-2 from mother to fetus or neonate: What to know and what to do?

SARS-CoV-2 can be vertically transmitted from the mother to the fetus and the neonate. This transmission route is rare compared to the environmental or horizontal spread and therefore, the risk can be deemed inconsequential by some medical providers. However, severe, although just as rare, feto-neonatal consequences are possible: fetal demise, severe/critical neonatal COVID-19 and multi-inflammatory syndrome (MIS-N) have been described. Therefore, it is important for the clinicians to know the mechanism of vertical transmission, how to recognize this, and how to deal with neonatal COVID-19 and MIS-N. Our knowledge about this field has significantly increased in the last three years. This is a summary of the pathophysiology, diagnostics, and therapeutics of vertical SARS-CoV-2 transmission that clinicians apply in their clinical practice.

Perinatal Outcome in Maternal COVID-19 infection at a Tertiary care Institute- A cross Sectional Study

Abstract

COVID 19 pandemic is one of the biggest challenge to health system of developing as well as developed countries. Because of the novelty of the virus, limited data were available regarding perinatal outcome. The objective of this study is to find out the perinatal outcome in COVID-19 infected mothers who delivered during COVID Pandemic.

Methodology

A cross sectional study was carried out at PCMC'S Post-Graduate Institute and YCM Hospital Pune (Maharashtra) from 1 May 2020 to 31 October 2021 which was a dedicated COVID hospital during COVID pandemic. A total of 362 maternity patients (including 5 twin pregnancies) having COVID 19 infection who gave birth to 367 Newborns were studied. Maternal COVID -19 infection was diagnosed either by RTPCR test or Rapid Antigen test. Demographic variables, maternal symptoms, labour and neonatal outcome were recorded. RT PCR of neonates at birth was performed. Data was analyzed statistically by using Epi Info Software.

Aim

To analyze the perinatal outcome among COVID-19 infected mothers who delivered during Covid pandemic.

Objectives

Study was conducted with the primary objective to analyze the labour outcome, maternal symptoms and secondarily to study maternal demographic profile and to compare disease severity during 1^st and 2^nd wave of COVID and to detect possibility of vertical transmission of COVID-19 in neonates of covid positive mothers.

Results

74.2% patients from young reproductive age (21-30 years age) were affected. All socioeconomic classes were affected. 61% patients were multigravida. Normal BMI was noted in 49.8%. 28.2% deliveries were preterm. Caesarean section rate was 50.5%. Following obstetric high risk factors were noted-anaemia in 34.2% followed by previous LSCS in 26.2% cases and preeclampsia in 18.7%Overall 54.6% patients were asymptomatic while 45.4% were symptomatic. Symptomatology between 1^st and 2^nd wave showed statistical significance (p value < .05%) for mild, moderate and severe symptoms. Myalgia, cough, fever and fatigue were common presenting symptoms. 14% patients required ICU/HDU care. HDU/ICU requirement showed statistical significance (p value < .05) between 1^st and 2^nd wave. Overall maternal mortality was 1.1% (4 maternal deaths in 2^nd wave) with no mortality in 1^st wave.96.4% were live births. Birth weight was more than 2.5 kg in 62% cases and 21.3% cases required NICU. Vertical transmission of COVID was seen in 1.1% cases.

Conclusion

Pregnant patients with moderate and severe disease are at higher risk of perinatal complications. ICU/HDU management with multidisciplinary management may reduce morbidity and mortality. Neonatal affection due to COVID may not be severe but may increase prematurity due to iatrogenic intervention.

The COVID-19 Pandemic and Pregnancy: Impact on Mothers and Newborns

The severe acute respiratory syndrome coronavirus 2 pandemic has markedly, and likely permanently, changed health care. This includes changing the obstetric and perinatal care of mothers and infants, and by extension, the care of their families. Infection during pregnancy is associated with an increased risk for severe coronavirus disease 2019 illness and related complications that can significantly impact maternal health and the health of the neonate. Viral transmission from mother to fetus is possible, but rare during pregnancy, and current health care policies focusing on maternal masking, and hand washing allows infected mothers to safely care for neonates (including nursing or feeding with expressed breast milk). The newly developed vaccines have been shown to be safe and effective for pregnant and breast-feeding mothers, with measurable antibody levels in cord blood and breast milk potentially providing a level of passive immunity to neonates. While studies looking at short-term outcomes for neonates have been reassuring, it is critical that we continue to work to understand and improve the care of pregnant woman and newborns with coronavirus disease 2019 to optimize long term outcomes. Although the knowledge base continues to evolve, the available evidence influencing the care of pregnant women and their infants is summarized in this focused review.

Clinical-pathological features in placentas of pregnancies with SARS-CoV-2 infection and adverse outcome: case series with and without congenital transmission

OBJECTIVE

To correlate clinical outcomes to pathology in SARS-CoV-2 infected placentas in stillborn and live-born infants presenting with fetal distress.

DESIGN

Retrospective, observational.

SETTING

Nationwide.

POPULATION

Five stillborn and nine live-born infants from 13 pregnant women infected with SARS-CoV-2 seeking care at seven different maternity units in Sweden.

METHODS

Clinical outcomes and placental pathology were studied in 14 cases (one twin pregnancy) of maternal SARS-CoV-2 infection with impaired fetal outcome. Outcomes were correlated to placental pathology in order to investigate the impact of virus-related pathology on the villous capillary endothelium, trophoblast and other cells.

MAIN OUTCOME MEASURES

Maternal and fetal clinical outcomes and placental pathology in stillborn and live-born infants.

RESULTS

Reduced fetal movements were reported (77%) and time from onset of maternal COVID-19 symptoms to signs of fetal distress among live-born infants was 6 (3-12) days and to diagnosis of stillbirth 11 (2-25) days. Two of the live-born infants died during the postnatal period. Signs of fetal distress led to emergency caesarean section in all live-born infants with umbilical cord blood gases and low Apgar scores confirming intrauterine hypoxia. Five stillborn and one live-born neonate had confirmed congenital transmission. Massive perivillous fibrinoid deposition, intervillositis and trophoblast necrosis were associated with SARS-CoV-2 placental infection and congenital transmission.

CONCLUSIONS

SARS-CoV-2 can cause rapid placental dysfunction with subsequent acute fetal hypoxia leading to intrauterine fetal compromise. Associated placental pathology included massive perivillous fibrinoid deposition, intervillositis and trophoblast degeneration.

What is the Hidden Biological Mechanism Underlying the Possible SARS-CoV-2 Vertical Transmission? A Mini Review

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS- CoV-2) represents an emerging infection that is spreading around the world. Among susceptible patients, pregnant women are more likely to develop serious complications and negative obstetric outcomes. Vertical transmission constitutes a debating issue which has not been completely understood. This review aims at describing the currently available evidence on SARS-CoV2 vertical transmission. We carried out a computerized literature search in the Cochrane Library, PubMed, Scopus and Web of Science, selecting the most relevant studies on vertical transmission from the outbreak onset until February 2022. The analysis of the available literature identifies the presence of SARS-CoV2 genome in different biological specimens, confirming the hypothesis that a transplacental infection can occur. In spite of the high number of infected people around the world, mother-to-child infections have been infrequently reported but it can be observed under certain biologic conditions. A deep knowledge of the underlying mechanisms of SARS-CoV2 vertical transmission is of paramount importance for planning an adequate management for the affected mothers and newborns.

SARS-CoV-2 positivity in offspring and timing of mother-to-child transmission: living systematic review and meta-analysis

OBJECTIVES

To assess the rates of SARS-CoV-2 positivity in babies born to mothers with SARS-CoV-2 infection, the timing of mother-to-child transmission and perinatal outcomes, and factors associated with SARS-CoV-2 status in offspring.

DESIGN

Living systematic review and meta-analysis.

DATA SOURCES

Major databases between 1 December 2019 and 3 August 2021.

STUDY SELECTION

Cohort studies of pregnant and recently pregnant women (including after abortion or miscarriage) who sought hospital care for any reason and had a diagnosis of SARS-CoV-2 infection, and also provided data on offspring SARS-CoV-2 status and risk factors for positivity. Case series and case reports were also included to assess the timing and likelihood of mother-to-child transmission in SARS-CoV-2 positive babies.

DATA EXTRACTION

Two reviewers independently extracted data and assessed study quality. A random effects model was used to synthesise data for rates, with associations reported using odds ratios and 95% confidence intervals. Narrative syntheses were performed when meta-analysis was inappropriate. The World Health Organization classification was used to categorise the timing of mother-to-child transmission (in utero, intrapartum, early postnatal).

RESULTS

472 studies (206 cohort studies, 266 case series and case reports; 28 952 mothers, 18 237 babies) were included. Overall, 1.8% (95% confidence interval 1.2% to 2.5%; 140 studies) of the 14 271 babies born to mothers with SARS-CoV-2 infection tested positive for the virus with reverse transcriptase polymerase chain reaction (RT-PCR). Of the 592 SARS-CoV-2 positive babies with data on the timing of exposure and type and timing of tests, 14 had confirmed mother-to-child transmission: seven in utero (448 assessed), two intrapartum (18 assessed), and five during the early postnatal period (70 assessed). Of the 800 SARS-CoV-2 positive babies with outcome data, 20 were stillbirths, 23 were neonatal deaths, and eight were early pregnancy losses; 749 babies were alive at the end of follow-up. Severe maternal covid-19 (odds ratio 2.4, 95% confidence interval 1.3 to 4.4), maternal death (14.1, 4.1 to 48.0), maternal admission to an intensive care unit (3.5, 1.7 to 6.9), and maternal postnatal infection (5.0, 1.2 to 20.1) were associated with SARS-CoV-2 positivity in offspring. Positivity rates using RT-PCR varied between regions, ranging from 0.1% (95% confidence interval 0.0% to 0.3%) in studies from North America to 5.7% (3.2% to 8.7%) in studies from Latin America and the Caribbean.

CONCLUSION

SARS-CoV-2 positivity rates were found to be low in babies born to mothers with SARS-CoV-2 infection. Evidence suggests confirmed vertical transmission of SARS-CoV-2, although this is likely to be rare. Severity of maternal covid-19 appears to be associated with SARS-CoV-2 positivity in offspring.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42020178076.

READERS' NOTE

This article is a living systematic review that will be updated to reflect emerging evidence. Updates may occur for up to two years from the date of original publication.

Detection of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) including Variant Analysis by Mass Spectrometry in Placental Tissue

Among neonates, tested positive for SARS-CoV-2, the majority of infections occur through postpartum transmission. Only few reports describe intrauterine or intrapartum SARS-CoV-2 infections in newborns. To understand the route of transmission, detection of the virus or virus nucleic acid in the placenta and amniotic tissue are of special interest. Current methods to detect SARS-CoV-2 in placental tissue are immunohistochemistry, electron microscopy, in-situ hybridization, polymerase chain reaction (PCR) and next-generation sequencing. Recently, we described an alternative method for the detection of viral ribonucleic acid (RNA), by combination of reverse transcriptase-PCR and mass spectrometry (MS) in oropharyngeal and oral swabs. In this report, we could detect SARS-CoV-2 in formal-fixed and paraffin-embedded (FFPE) placental and amniotic tissue by multiplex RT-PCR MS. Additionally, we could identify the British variant (B.1.1.7) of the virus in this tissue by the same methodology. Combination of RT-PCR with MS is a fast and easy method to detect SARS-CoV-2 viral RNA, including specific variants in FFPE tissue.

Detection of SARS-CoV-2 in Neonatal Autopsy Tissues and Placenta

Severe coronavirus disease in neonates is rare. We analyzed clinical, laboratory, and autopsy findings from a neonate in the United States who was delivered at 25 weeks of gestation and died 4 days after birth; the mother had asymptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and preeclampsia. We observed severe diffuse alveolar damage and localized SARS-CoV-2 by immunohistochemistry, in situ hybridization, and electron microscopy of the lungs of the neonate. We localized SARS-CoV-2 RNA in neonatal heart and liver vascular endothelium by using in situ hybridization and detected SARS-CoV-2 RNA in neonatal and placental tissues by using reverse transcription PCR. Subgenomic reverse transcription PCR suggested viral replication in lung/airway, heart, and liver. These findings indicate that in utero SARS-CoV-2 transmission contributed to this neonatal death.

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.

Placental SARS-CoV-2 distribution correlates with level of tissue oxygenation in COVID-19-associated necrotizing histiocytic intervillositis/perivillous fibrin deposition

Introduction

Recent evidence supports the – rare – occurrence of vertical transplacental SARS-CoV-2 transmission. We previously determined that placental expression of angiotensin-converting enzyme 2 (ACE2), the SARS-CoV-2 receptor, and associated viral cell entry regulators is upregulated by hypoxia. In the present study, we utilized a clinically relevant model of SARS-CoV-2-associated chronic histiocytic intervillositis/massive perivillous fibrin deposition (CHIV/MPFVD) to test the hypothesis that placental hypoxia may facilitate placental SARS-CoV-2 infection.

Methods

We performed a comparative immunohistochemical and/or RNAscope in-situ hybridization analysis of carbonic anhydrase IX (CAIX, hypoxia marker), ACE2 and SARS-CoV-2 expression in free-floating versus fibrin-encased chorionic villi in a 20-weeks’ gestation placenta with SARS-CoV-2-associated CHIV/MPVFD.

Results

The levels of CAIX and ACE2 immunoreactivity were significantly higher in trophoblastic cells of fibrin-encased villi than in those of free-floating villi, consistent with hypoxia-induced ACE2 upregulation. SARS-CoV-2 showed a similar preferential localization to trophoblastic cells of fibrin-encased villi.

Discussion

The localization of SARS-CoV-2 to hypoxic, fibrin-encased villi in this placenta with CHIV/MPVFD suggests placental infection and, therefore, transplacental SARS-CoV-2 transmission may be promoted by hypoxic conditions, mediated by ACE2 and similar hypoxia-sensitive viral cell entry mechanisms. Understanding of a causative link between placental hypoxia and SARS-CoV-2 transmittability may potentially lead to the development of alternative strategies for prevention of intrauterine COVID-19 transmission.

Clinical characteristics and evolution of 71 neonates born to mothers with COVID-19 at a tertiary center in Brazil

INTRODUCTION

Limited data are available on pregnant women with COVID-19 and their neonates.

OBJECTIVE

This study aimed to describe clinical characteristics and evolution from birth to discharge of a retrospective cohort of 71 neonates, with one set of twins, born to women with COVID-19 diagnosed at the end of pregnancy. The authors included all newborns admitted into a neonatal unit of a tertiary hospital in Brazil, between March 2020 and March 2021, whose unvaccinated mothers had COVID-19 symptoms and RT-PCR (Real-Time Polymerase Chain Reaction) for SARS-CoV-2 positive within fourteen days prior to delivery. Newborns to mothers with COVID-19 symptoms and negative tests for SARS-CoV-2 were excluded.

RESULTS

The main route of birth delivery was cesarean, corresponding to 60 pregnant women (84.5%). The foremost indications for cesarean were pregnant with critical disease (24.6%) and acute fetal distress (20.3%). The mean birth weight was 2452 g (865‒3870 g) and the mean gestational age was 34^5/7 weeks (25‒40 weeks). There were 45 premature newborns (63.3%), of which 21 newborns (29.5%) were less than 32 weeks of gestational age. RT-PCR for SARS-CoV-2 on oropharyngeal swabs was positive in 2 newborns (2.8%) and negative in the other 69 newborns (97.2%). Most newborns (51.4%) needed respiratory support. Therapeutic interventions during hospitalization were inotropic drugs (9.9%), antibiotics (22.8%), parenteral nutrition (26.8%), and phototherapy (46.5%).

CONCLUSION

Maternal COVID-19 diagnosticated close to delivery has an impact on the first days of neonatal life.

A Neonate With Vertical Transmission of COVID-19 and Acute Respiratory Failure: A Case Report

BACKGROUND

This case describes a case of vertical transmission of COVID-19 from a mother to her neonate. The neonate subsequently developed acute respiratory failure consistent with adult symptoms of COVID-19.

CLINICAL FINDINGS

This preterm neonate was born at 33 4/7 weeks' gestational age to a COVID-19-positive mother and admitted to the neonatal intensive care unit (NICU) for prematurity and respiratory distress. The neonate developed acute respiratory failure with severe persistent pulmonary hypertension of newborn (PPHN) and required intubation and maximum respiratory and cardiovascular support. The neonate subsequently tested positive for COVID-19 at 24 hours of life.

PRIMARY DIAGNOSIS

Acute respiratory failure related to COVID-19 infection.

INTERVENTIONS

The neonate was admitted to the NICU on CPAP. At 11 hours of life, the neonate began to exhibit signs of worsening respiratory distress requiring intubation, mechanical, and high frequency ventilation. An echocardiogram revealed severe PPHN. The neonate required dopamine to manage hypotension and was treated with steroids to decrease inflammation associated with airway edema noted during intubation. Pharmaceutically induced paralysis, analgesia, and sedation was used to manage persistent hypoxia.

OUTCOMES

The neonate fully recovered from acute respiratory failure and was discharged home with the mother.

PRACTICE RECOMMENDATIONS

Newborns born to mothers who are positive for COVID-19 are at risk for vertical transmission of COVID-19 and should be monitored closely for acute respiratory failure. Respiratory medical management should include supportive care. Staff should also encourage parents to consider receiving the COVID-19 vaccine to protect their newborn from the possibility of developing acute respiratory failure.

Frequent Placental SARS-CoV-2 in Patients with COVID-19-Associated Hypertensive Disorders of Pregnancy

Introduction

Studies described an increased frequency of hypertensive disorders of pregnancy (HDP) after a COVID-19 episode. There is limited evidence about SARS-CoV-2 viral load in placenta. This study aimed to investigate the relationship between SARS-CoV-2 viral load in the placenta and clinical development of HDP after COVID-19 throughout different periods of gestation.

Methods

This is a case-control study in women with and without gestational hypertensive disorders after SARS-CoV-2 infection diagnosed by RT-PCR during pregnancy. Patients were matched by gestational age at the moment of COVID-19 diagnosis. We performed an analysis of SARS-CoV-2 RNA levels in placenta.

Results

A total of 28 women were enrolled. Sixteen patients were diagnosed with COVID-19 during the third trimester and the remaining 12 patients in the other trimesters. Ten placentas (35.7%) were positive for SARS-CoV-2, 9 of them (9/14, 64.3%) belonged to the HDP group versus 1 (1/14, 7.2%) in the control group (p = 0.009). Those cases with the highest loads of viral RNA developed severe preeclampsia (PE).

Conclusion

Among women diagnosed with COVID-19 during pregnancy, the presence of SARS-CoV-2 in the placenta was more frequent among women suffering from PE or gestational hypertension. Furthermore, the most severe cases of HDP were associated with high placental viral load, not necessarily associated with a positive nasopharyngeal RT-PCR at delivery. Our data suggest that SARS-CoV-2 infection during pregnancy could trigger gestational hypertensive disorders through persistent placental infection and resulting placental damage.

Hypertensive disease, preterm birth, fetal growth restriction and chronic inflammatory disorders of the placenta: experiences in a single institution with a standardized protocol of investigation

PURPOSE

Chronic inflammatory disorders of the placenta, in particular villitis of unknown etiology (VUE), chronic deciduitis (CD), chronic chorioamnionitis (CC), chronic histiocytic intervillositis (CHI), and eosinophilic/T-cell chorionic vasculitis (ETCV) can exclusively be diagnosed histologically. Using a standardized procedure for submission and pathological-anatomical examination of placentas in a single perinatal care center, we analyzed the association of chronic placental lesions to perinatal complications.

METHODS

We reviewed all singleton placentas and miscarriages that were examined histologically over a period of ten years after having implemented a standardized protocol for placental submission in our hospital. Cases with chronic inflammatory lesions were identified, and clinical data were analyzed and compared with a focus on preterm birth, hypertensive disorders, and fetal growth restriction and/or fetal demise.

RESULTS

In 174 placentas, at least one of the chronic inflammatory entities was diagnosed. CD was the most frequent disorder (n = 95), and had strong associations with preterm birth (47.3% of all cases with CD) and intrauterine fetal demise. VUE (n = 74) was exclusively diagnosed in the third trimester. This disorder was associated with a birth weight below the 10th percentile (45% of the cases) and hypertensive disease in pregnancy. Miscarriage and intrauterine fetal demise were associated with CHI (in 66.7% of cases, n = 18).

CONCLUSIONS

Chronic inflammatory disorders are frequently observed and contribute to major obstetric and perinatal complications. Further studies are needed to get a better picture of the connection between adverse obstetric outcomes and chronic inflammation to aid in the better counseling of patients.

Congenital Infection of Severe Acute Respiratory Syndrome Coronavirus 2 With Intrauterine Fetal Death: A Clinicopathological Study With Molecular Analysis

BACKGROUND

Observations of vertical transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection from mother to fetus have recently been described in the literature. However, the consequences of such transmission, whether fetal or neonatal, are poorly understood.

METHODS

From a case of in utero fetal death at 24+2 weeks of gestation that occurred 7 days after the diagnosis of symptomatic SARS-CoV-2 infection in the mother, we isolated the incriminating virus by immunochemistry and molecular techniques in several fetal tissues, with a variant analysis of the SARS-CoV-2 genome.

RESULTS

The fetal demise could be explained by the presence of placental histological lesions, such as histiocytic intervillositis and trophoblastic necrosis, in addition to fetal tissue damage. We observed mild fetal growth retardation and visceral damage to the liver, causing hepatocellular damage and hemosiderosis. To the best of our knowledge, this is the first report in the literature of fetal demise secondary to maternal-fetal transmission of SARSCoV- 2 with a congenital infection and a pathological description of placental and fetal tissue damage.

CONCLUSIONS

SARS-CoV-2 was identified in both specimens using 3 independent techniques (immunochemistry, real-time quantitative polymerase chain reaction, and realtime digital polymerase chain reaction). Furthermore, the incriminating variant has been identified.

Association of SARS-CoV-2 placental histopathology findings with maternal-fetal comorbidities and severity of COVID-19 hypoxia

OBJECTIVE

SARS-CoV-2 is known to impact multiple organ systems, with growing data to suggest the potential for placental infection and resultant pathology. Understanding how maternal COVID-19 disease can affect placental histopathology has been limited by small study cohorts with mild disease, review by multiple pathologists, and potential confounding by maternal-fetal comorbidities that can also influence placental findings. This study aims to identify pathologic placental findings associated with COVID-19 disease and severity, as well as to distinguish them from changes related to coexisting maternal-fetal comorbidities.

METHODS

This is an observational study of 61 pregnant women with confirmed SARS-CoV-2 infection who delivered and had a placental histological evaluation at NYU Langone Health between March 19, 2020 and June 30, 2020. Primary outcomes were the prevalence of placental histopathologic features and their association with maternal-fetal comorbidities and severity of COVID-19 related hypoxia. Analysis was performed using Fisher's exact test and t-test with p < 0.05 considered significant.

RESULTS

Sixty-one placentas were included in the study cohort, 71% from pregnancies complicated by at least one maternal-fetal comorbidity. Twenty-five percent of placentas were small for gestational age and 77% exhibited at least one feature of maternal vascular malperfusion. None of the histopathologic features in the examined placentas were associated with the presence of any specific maternal-fetal comorbidity. Thirteen percent of the cohort required maternal respiratory support for COVID-19 related hypoxia. Villous trophoblast necrosis was associated with maternal supplemental oxygen requirement (67 vs. 33%, p = 0.04) and intubation (67 vs. 33%, p = 0.01).

CONCLUSION

In pregnancies complicated by COVID-19 disease, there was a high prevalence of placental histopathologic changes identified, particularly features of maternal vascular malperfusion, which could not be attributed solely to the presence of maternal-fetal comorbidities. The significantly increased prevalence of villous trophoblast necrosis in women needing respiratory support suggests a connection to the severity of COVID-19 illness.

Molecular Pathology Demonstration of SARS-CoV-2 in Cytotrophoblast from Placental Tissue with Chronic Histiocytic Intervillositis, Trophoblast Necrosis and COVID-19

A subset of placentas from pregnant women having the SARS-CoV-2 infection have been found to be infected with the coronavirus using molecular pathology methods including immunohistochemistry and RNA in situ hybridization. These infected placentas can demonstrate several unusual findings which occur together-chronic histiocytic intervillositis, trophoblast necrosis and positive staining of the syncytiotrophoblast for SARS-CoV-2. They frequently also have increased fibrin deposition, which can be massive in some cases. Syncytiotrophoblast is the most frequent fetal-derived cell type to be positive for SARS-CoV-2. It has recently been shown that in a small number of infected placentas, villous stromal macrophages, termed Hofbauer cells, and villous capillary endothelial cells can also stain positive for SARS-CoV-2. This report describes a placenta from a pregnant woman with SARS-CoV-2 that had chronic histiocytic intervillositis, trophoblast necrosis, increased fibrin deposition and positive staining of the syncytiotrophoblast for SARS-CoV-2. In addition, molecular pathology testing including RNAscope and immunohistochemistry for SARS-CoV-2 and double-staining immunohistochemistry using antibodies to E-cadherin and GATA3 revealed that cytotrophoblast cells stained intensely for SARS-CoV-2. All of the cytotrophoblast cells that demonstrated positive staining for SARS-CoV-2 were in direct physical contact with overlying syncytiotrophoblast that also stained positive for the virus. The pattern of cytotrophoblast staining for SARS-CoV-2 was patchy, and there were chorionic villi having diffuse positive staining of the syncytiotrophoblast for SARS-CoV-2, but without staining of cytotrophoblast. This first detailed description of cytotrophoblast involvement by SARS-CoV-2 adds another fetal cell type from infected placentas that demonstrate viral staining.

Role of ACE2 in pregnancy and potential implications for COVID-19 susceptibility

In times of coronavirus disease 2019 (COVID-19), the impact of severe acute respiratory syndrome (SARS)-coronavirus (CoV)-2 infection on pregnancy is still unclear. The presence of angiotensin-converting enzyme (ACE) 2 (ACE2), the main receptor for SARS-CoV-2, in human placentas indicates that this organ can be vulnerable for viral infection during pregnancy. However, for this to happen, additional molecular processes are critical to allow viral entry in cells, its replication and disease manifestation, particularly in the placenta and/or feto-maternal circulation. Beyond the risk of vertical transmission, COVID-19 is also proposed to deplete ACE2 protein and its biological actions in the placenta. It is postulated that such effects may impair essential processes during placentation and maternal hemodynamic adaptations in COVID-19 pregnancy, features also observed in several disorders of pregnancy. This review gathers information indicating risks and protective features related to ACE2 changes in COVID-19 pregnancies. First, we describe the mechanisms of SARS-CoV-2 infection having ACE2 as a main entry door and current evidence of viral infection in the placenta. Further, we discuss the central role of ACE2 in physiological systems such as the renin-angiotensin system (RAS) and the kallikrein-kinin system (KKS), both active during placentation and hemodynamic adaptations of pregnancy. Significant knowledge gaps are also identified and should be urgently filled to better understand the fate of ACE2 in COVID-19 pregnancies and the potential associated risks. Emerging knowledge will be able to improve the early stratification of high-risk pregnancies with COVID-19 exposure as well as to guide better management and follow-up of these mothers and their children.

Hofbauer cells and coronavirus disease 2019 (COVID-19) in pregnancy: Molecular pathology analysis of villous macrophages, endothelial cells, and placental findings from 22 placentas infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with and without fetal transmission

CONTEXT

- Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can undergo maternal-fetal transmission, heightening interest in the placental pathology findings from this infection. Transplacental SARS-CoV-2 transmission is typically accompanied by chronic histiocytic intervillositis together with necrosis and positivity of syncytiotrophoblast for SARSCoV-2. Hofbauer cells are placental macrophages that have been involved in viral diseases including HIV and Zika virus, but their involvement in SARS-CoV-2 in unknown.

OBJECTIVE

- To determine whether SARS-CoV-2 can extend beyond the syncytiotrophoblast to enter Hofbauer cells, endothelium and other villous stromal cells in infected placentas of liveborn and stillborn infants.

DESIGN

- Case-based retrospective analysis by 29 perinatal and molecular pathology specialists of placental findings from a preselected cohort of 22 SARS-CoV-2-infected placentas delivered to pregnant women testing positive for SARS-CoV-2 from 7 countries. Molecular pathology methods were used to investigate viral involvement of Hofbauer cells, villous capillary endothelium, syncytiotrophoblast and other fetal-derived cells.

RESULTS

- Chronic histiocytic intervillositis and trophoblast necrosis was present in all 22 placentas (100%). SARS-CoV-2 was identified in Hofbauer cells from 4/22 placentas (18%). Villous capillary endothelial staining was positive in 2/22 cases (9%), both of which also had viral positivity in Hofbauer cells. Syncytiotrophoblast staining occurred in 21/22 placentas (95%). Hofbauer cell hyperplasia was present in 3/22 placentas (14%). In the 7 cases having documented transplacental infection of the fetus, 2 occurred in placentas with Hofbauer cell staining positive for SARS-CoV-2.

CONCLUSIONS

- SARS-CoV-2 can extend beyond the trophoblast into the villous stroma, involving Hofbauer cells and capillary endothelial cells, in a small number of infected placentas. Most cases of SARS-CoV-2 transplacental fetal infection occur without Hofbauer cell involvement.

A systematic review of pregnant women with COVID-19 and their neonates

BACKGROUND

In December 2019, a novel coronavirus disease (COVID-19) emerged in Wuhan, China, with an incredible contagion rate. However, the vertical transmission of COVID-19 is uncertain.

OBJECTIVES

This is a systematic review of published studies concerning pregnant women with confirmed COVID-19 and their neonates.

SEARCH STRATEGY

We carried out a systematic search in multiple databases, including PubMed, Web of Science, Google Scholar, Scopus, and WHO COVID-19 database using the following keywords: (Coronavirus) OR (novel coronavirus) OR (COVID-19) OR (COVID19) OR (COVID 19) OR (SARS-CoV2) OR (2019-nCoV)) and ((pregnancy) OR (pregnant) OR (vertical transmission) OR (neonate) OR (newborn) OR (placenta) OR (fetus) OR (Fetal)). The search took place in April 2020.

SELECTION CRITERIA

Original articles published in English were eligible if they included pregnant patients infected with COVID-19 and their newborns.

DATA COLLECTION AND ANALYSES

The outcomes of interest consisted of clinical manifestations of COVID-19 in pregnant patients with COVID-19 and also the effect of COVID-19 on neonatal and pregnancy outcomes.

MAIN RESULTS

37 articles involving 364 pregnant women with COVID-19 and 302 neonates were included. The vast majority of pregnant patients were in their third trimester of pregnancy, and only 45 cases were in the first or second trimester (12.4%). Most mothers described mild to moderate manifestations of COVID-19. Of 364 pregnant women, 25 were asymptomatic at the time of admission. The most common symptoms were fever (62.4%) and cough (45.3%). Two maternal deaths occurred. Some pregnant patients (12.1%) had a negative SARS-CoV-2 test but displayed clinical manifestations and abnormalities in computed tomography (CT) scan related to COVID-19. Twenty-two (6.0%) pregnant patients developed severe pneumonia. Two maternal deaths occurred from severe pneumonia and multiple organ dysfunction. Studies included a total of 302 neonates from mothers with COVID-19. Of the studies that provided data on the timing of birth, there were 65 (23.6%) preterm neonates. One baby was born dead from a mother who also died from COVID-19. Of the babies born alive from mothers with COVID-19, five newborns faced critical conditions, and two later died. A total of 219 neonates underwent nasopharyngeal specimen collection for SARS-CoV-2, of which 11 tested positive (5%). Seventeen studies examined samples of the placenta, breast milk, umbilical cord, and amniotic fluid, and all tested negative except one amniotic fluid sample.

CONCLUSIONS

A systematic review of published studies confirm that the course of COVID-19 in pregnant women resembles that of other populations. However, there is not sufficient evidence to establish an idea that COVID-19 would not complicate pregnancy.

Clinical and in Vitro Evidence against Placenta Infection at Term by Severe Acute Respiratory Syndrome Coronavirus 2

Despite occasional reports of vertical transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during pregnancy, the question of placental infection and its consequences for the newborn remain unanswered. Herein, we analyzed the placentas of 31 coronavirus disease 2019–positive mothers by reverse transcriptase PCR, immunohistochemistry, and in situ hybridization. Only one case of placental infection was detected, which was associated with intrauterine demise of the fetus. Differentiated primary trophoblasts were then isolated from nonpathologic human placentas at term, differentiated, and exposed to SARS-CoV-2 virions. Unlike for positive control cells Vero E6, the virus inside cytotrophoblasts and syncytiotrophoblasts or in the supernatant 4 days after infection was undetectable. As a mechanism of defense, we hypothesized that trophoblasts at term do not express angiotensin-converting enzyme 2 and transmembrane protease serine 2 (TMPRSS2), the two main host membrane receptors for SARS-CoV-2 entry. The quantification of these proteins in the placenta during pregnancy confirmed the absence of TMPRSS2 at the surface of the syncytium. Surprisingly, a transiently induced experimental expression of TMPRSS2 did not allow the entry or replication of the virus in differentiated trophoblasts. Altogether, these results underline that trophoblasts are not likely to be infected by SARS-CoV-2 at term, but raise concern about preterm infection.

Association Between COVID-19 Pregnant Women Symptoms Severity and Placental Morphologic Features

Since the beginning of the pandemic, few papers describe the placenta’s morphological and morphometrical features in SARS-CoV-2–positive pregnant women. Alterations, such as low placental weight, accelerated villous maturation, decidual vasculopathy, infarcts, thrombosis of fetal placental vessels, and chronic histiocytic intervillositis (CHI), have been described.

Coronavirus Diseases in Pregnant Women, the Placenta, Fetus, and Neonate

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the etiological agent of coronavirus disease 2019 (COVID-19), is similar to two other coronaviruses, severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV), in causing life-threatening respiratory infections and systemic complications in both children and adults. As the COVID-19 pandemic has continued to spread globally, increasing numbers of pregnant women have become infected, raising concern not only for their health but also for the health of their infants. This chapter discusses the effects of coronavirus infections, e.g., MERS, SARS, and COVID 19, on pregnancy and describes the evolving knowledge of COVID 19 among pregnant women. The physiological changes that occur in pregnancy, especially changes in the immune system, are reviewed in terms of their effect on susceptibility to infectious diseases. The effects of COVID-19 on the placenta, fetus, and neonate are also reviewed, including potential clinical outcomes and issues relating to testing and diagnosis. The potential mechanisms of vertical transmission of the virus between pregnant women and their infants are analyzed, including intrauterine, intrapartum, and postpartum infections. Several recent studies have reported the detection of SARS-CoV-2 in tissues from the fetal side of the placenta, permitting the diagnosis of transplacental infection of the fetus by SARS-CoV-2. Placentas from infected mothers in which intrauterine transplacental transmission of SARS-CoV-2 has occurred demonstrate an unusual combination of pathology findings which may represent risk factors for placental as well as fetal infection.

Chronic Histiocytic Intervillositis With Trophoblast Necrosis Is a Risk Factor Associated With Placental Infection From Coronavirus Disease 2019 (COVID-19) and Intrauterine Maternal-Fetal Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Transmission in Live-Born and Stillborn Infants

CONTEXT.—

The number of neonates with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is increasing, and in a few there are reports of intrauterine infection.

OBJECTIVE.—

To characterize the placental pathology findings in a preselected cohort of neonates infected by transplacental transmission arising from maternal infection with SARS-CoV-2, and to identify pathology risk factors for placental and fetal infection.

DESIGN.—

Case-based retrospective analysis by a multinational group of 19 perinatal specialists of the placental pathology findings from 2 cohorts of infants delivered to mothers testing positive for SARS-CoV-2: live-born neonates infected via transplacental transmission who tested positive for SARS-CoV-2 after delivery and had SARS-CoV-2 identified in cells of the placental fetal compartment by molecular pathology, and stillborn infants with syncytiotrophoblast positive for SARS-CoV-2.

RESULTS.—

In placentas from all 6 live-born neonates acquiring SARS-CoV-2 via transplacental transmission, the syncytiotrophoblast was positive for coronavirus using immunohistochemistry, RNA in situ hybridization, or both. All 6 placentas had chronic histiocytic intervillositis and necrosis of the syncytiotrophoblast. The 5 stillborn/terminated infants had placental pathology findings that were similar, including SARS-CoV-2 infection of the syncytiotrophoblast, chronic histiocytic intervillositis, and syncytiotrophoblast necrosis.

CONCLUSIONS.—

Chronic histiocytic intervillositis together with syncytiotrophoblast necrosis accompanies SARS-CoV-2 infection of syncytiotrophoblast in live-born and stillborn infants. The coexistence of these 2 findings in all placentas from live-born infants acquiring their infection prior to delivery indicates that they constitute a pathology risk factor for transplacental fetal infection. Potential mechanisms of infection of the placenta and fetus with SARS-CoV-2, and potential future studies, are discussed.

COVID-19: Heterogeneous Excess Mortality and "Burden of Disease" in Germany and Italy and Their States and Regions, January-June 2020

Total mortality and "burden of disease" in Germany and Italy and their states and regions were explored during the first COVID-19 wave by using publicly available data for 16 German states and 20 Italian regions from January 2016 to June 2020. Based on expectations from 2016 to 2019, simplified Standardized Mortality Ratios (SMRs) for deaths occurring in the first half of 2020 and the effect of changed excess mortality in terms of "burden of disease" were assessed. Moreover, whether two German states and 19 Italian cities appropriately represent the countries within the European monitoring of excess mortality for public health action (EuroMOMO) network was explored. Significantly elevated SMRs were observed (Germany: week 14-18, Italy: week 11-18) with SMR peaks in week 15 in Germany (1.15, 95%-CI: 1.09-1.21) and in week 13 in Italy (1.79, 95%-CI: 1.75-1.83). Overall, SMRs were 1.00 (95%-CI: 0.97-1.04) in Germany and 1.06 (95%-CI: 1.03-1.10) in Italy. Significant SMR heterogeneity was found within both countries. Age and sex were strong modifiers. Loss of life expectancy was 0.34 days (1.66 days in men) for Germany and 5.3 days (6.3 days in men) for Italy [with upper limits of 3 and 6 weeks among elderly populations (≥65 years) after maximum potential bias adjustments]. Restricted data used within EuroMOMO neither represents mortality in the countries as a whole nor in their states and regions adequately. Mortality analyses with high spatial and temporal resolution are needed to monitor the COVID-19 pandemic's course.

Molecular Pathology Analysis of SARS-CoV-2 in Syncytiotrophoblast and Hofbauer Cells in Placenta from a Pregnant Woman and Fetus with COVID-19

A small number of neonates delivered to women with SARS-CoV-2 infection have been found to become infected through intrauterine transplacental transmission. These cases are associated with a group of unusual placental pathology abnormalities that include chronic histiocytic intervillositis, syncytiotrophoblast necrosis, and positivity of the syncytiotrophoblast for SARS-CoV-2 antigen or RNA. Hofbauer cells constitute a heterogeneous group of immunologically active macrophages that have been involved in transplacental infections that include such viral agents as Zika virus and human immunodeficiency virus. The role of Hofbauer cells in placental infection with SARS-CoV-2 and maternal-fetal transmission is unknown. This study uses molecular pathology techniques to evaluate the placenta from a neonate infected with SARS-CoV-2 via the transplacental route to determine whether Hofbauer cells have evidence of infection. We found that the placenta had chronic histiocytic intervillositis and syncytiotrophoblast necrosis, with the syncytiotrophoblast demonstrating intense positive staining for SARS-CoV-2. Immunohistochemistry using the macrophage marker CD163, SARS-CoV-2 nucleocapsid protein, and double staining for SARS-CoV-2 with RNAscope and anti-CD163 antibody, revealed that no demonstrable virus could be identified within Hofbauer cells, despite these cells closely approaching the basement membrane zone of the infected trophoblast. Unlike some other viruses, there was no evidence from this transmitting placenta for infection of Hofbauer cells with SARS-CoV-2.

Preterm care during the COVID-19 pandemic: A comparative risk analysis of neonatal deaths averted by kangaroo mother care versus mortality due to SARS-CoV-2 infection

BACKGROUND

COVID-19 is disrupting health services for mothers and newborns, particularly in low- and middle-income countries (LMIC). Preterm newborns are particularly vulnerable. We undertook analyses of the benefits of kangaroo mother care (KMC) on survival among neonates weighing ≤2000 g compared with the risk of SARS-CoV-2 acquired from infected mothers/caregivers.

METHODS

We modelled two scenarios over 12 months. Scenario 1 compared the survival benefits of KMC with universal coverage (99%) and mortality risk due to COVID-19. Scenario 2 estimated incremental deaths from reduced coverage and complete disruption of KMC. Projections were based on the most recent data for 127 LMICs (~90% of global births), with results aggregated into five regions.

FINDINGS

Our worst-case scenario (100% transmission) could result in 1,950 neonatal deaths from COVID-19. Conversely, 125,680 neonatal lives could be saved with universal KMC coverage. Hence, the benefit of KMC is 65-fold higher than the mortality risk of COVID-19. If recent evidence of 10% transmission was applied, the ratio would be 630-fold. We estimated a 50% reduction in KMC coverage could result in 12,570 incremental deaths and full disruption could result in 25,140 incremental deaths, representing a 2·3-4·6% increase in neonatal mortality across the 127 countries.

INTERPRETATION

The survival benefit of KMC far outweighs the small risk of death due to COVID-19. Preterm newborns are at risk, especially in LMICs where the consequences of disruptions are substantial. Policymakers and healthcare professionals need to protect services and ensure clearer messaging to keep mothers and newborns together, even if the mother is SARS-CoV-2-positive.

FUNDING

Eunice Kennedy Shriver National Institute of Child Health & Human Development; Bill & Melinda Gates Foundation; Elma Philanthropies; Wellcome Trust; and Joint Global Health Trials scheme of Department of Health and Social Care, Department for International Development, Medical Research Council, and Wellcome Trust.

Gestation and COVID-19: clinical and microbiological observational study (Gesta-COVID19)

BACKGROUND

The Coronavirus Disease 2019 (COVID-19) is a novel disease which has been having a worldwide affect since December 2019. Evidence regarding the effects of SARS-CoV-2 during pregnancy is conflicting. The presence of SARS-CoV-2 has been demonstrated in biological samples during pregnancy (placenta, umbilical cord or amniotic fluid); however, maternal and fetal effects of the virus are not well known.

METHODS

Descriptive, multicentre, longitudinal, observational study in eight tertiary care hospitals throughout Spain, that are referral centres for pregnant women with COVID-19. All pregnant women with positive SARS-CoV-2 real-time reverse transcriptase polymerase chain reaction during their pregnancy or 14 days preconception and newborns born to mothers infected with SARS-CoV-2 will be included. They will continue to be followed up until 4 weeks after delivery. The aim of the study is to investigate both the effect of COVID-19 on the pregnancy, and the effect of the pregnancy status with the evolution of the SARS-CoV-2 disease. Other samples (faeces, urine, serum, amniotic fluid, cord and peripheral blood, placenta and breastmilk) will be collected in order to analyse whether or not there is a risk of vertical transmission and to describe the behaviour of the virus in other fluids. Neonates will be followed until 6 months after delivery to establish the rate of neonatal transmission. We aim to include 150 pregnant women and their babies. Ethics approval will be obtained from all the participating centres.

DISCUSSION

There is little information known about COVID-19 and its unknown effects on pregnancy. This study will collect a large number of samples in pregnant women which will allow us to demonstrate the behaviour of the virus in pregnancy and postpartum in a representative cohort of the Spanish population.

Placental pathology of the third trimester pregnant women from COVID-19

Aims

To explore the clinical characteristics and placental pathological changes of pregnant women with 2019 novel coronavirus (CoV) disease (COVID-19) in the third trimester, and to assess the possibility of vertical transmission.

Methods and results

The placenta tissues were evaluated by using immunohistochemistry for inflammatory cells and Hofbauer cells, and using severe acute respiratory syndrome (SARS) CoV-2 RNA Fluorescence In-Situ Hybridization (FISH) and SARS-CoV-2 spike protein immunofluorescence (IF) double staining. All eight placentas from the third trimester pregnancy women were studied. All patients were cured, no clinical or serological evidence pointed to vertical transmission of SARS-CoV-2. Features of maternal vascular malperfusion (MVM) such as increased syncytial knots were present in all 8 cases (8/8), and increased focal perivillous fibrin depositions were presented in 7 cases (7/8). No significate chronic histiocytic intervillositis was noted in the placenta. The number of macrophages and inflammatory cells such as T cells, B cells and plasma cells in the placental villous was not significantly increased in all cases. Moreover, all of eight cases demonstrated negative results by FISH using a SARS-CoV-2 virus RNA probe and by IF using a monoclonal antibody against SARS-CoV-2 spike protein.

Conclusions

We found no evidence of vertical transmission and adverse maternal-fetal outcomes in the placentas of third trimester COVID-19 pregnancy women, which provided further information for the clinical management of those women in the third trimester. However, further studies are still needed for patients with infections in different stage of gestation, especially in first and second trimester.

The effects of COVID-19 on pregnancy and implications for reproductive medicine

COVID-19 was officially declared a pandemic in March 2020. Since then, our understanding of its effects on pregnancy have evolved rapidly. Emerging surveillance data and large cohort studies suggest that pregnancy is associated with an increased risk of intensive care unit hospitalization, invasive ventilation, and death. Pregnancies complicated by SARS-CoV-2 infection are associated with increased likelihood of cesarean delivery and preterm birth. Intrauterine transmission occurs, but seems to be rare. Critical gaps remain, and rigorous high-quality data are needed to better ascertain pregnancy risks and to inform antenatal and obstetrical management.

The Impacts of COVID-19 on US Maternity Care Practices: A Followup Study

This article extends the findings of a rapid response article researched in April 2020 to illustrate how providers' practices and attitudes toward COVID-19 had shifted in response to better evidence, increased experience, and improved guidance on how SARS-CoV-2 and COVID-19 impacted maternity care in the United States. This article is based on a review of current labor and delivery guidelines in relation to SARS-CoV-2 and COVID-19, and on an email survey of 28 community-based and hospital-based maternity care providers in the United State, who discuss their experiences and clients' needs in response to a rapidly shifting landscape of maternity care during the COVID-19 pandemic. One-third of our respondents are obstetricians, while the other two-thirds include midwives, doulas, and labor and delivery nurses. We present these providers' frustrations and coping mechanisms in shifting their practices in relation to COVID-19. The primary lessons learned relate to improved testing and accessing PPE for providers and clients; the need for better integration between community- and hospital-based providers; and changes in restrictive protocols concerning labor support persons, rooming-in with newborns, immediate skin-to-skin contact, and breastfeeding. We conclude by suggesting that the COVID-19 pandemic offers a transformational moment to shift maternity care in the United States toward a more integrated and sustainable model that might improve provider and maternal experiences as well as maternal and newborn outcomes.