Low placental weight and altered metabolic scaling after severe acute respiratory syndrome coronavirus type 2 infection during pregnancy: a prospective multicentric study

The pregnancy outcomes of women with SARS-CoV-2 infection in the first trimester ---a longitudinal cohort study

BACKGROUND

In recent years, severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) infection has been prevalent worldwide. Pregnant women belong to a special group, and it is very important for clinicians to pay attention to the impact of SARS-CoV-2 infection on pregnancy outcomes. However, there are limited studies on the impact of SARS-CoV-2 infection on pregnancy outcomes during the first trimester.

OBJECTIVE

To investigate the effect of SARS-CoV-2 infection in the first trimester on pregnancy outcomes.

METHODS

Clinical information of pregnant women whose last menstrual period was between October 1, 2022, and April 1, 2023, and who were registered in the Obstetrics and Gynecology department of Peking University International Hospital, was analyzed. Among them, 498 pregnant women with SARS-CoV-2 infection in the first trimester were included in the study group; while a total of 654 pregnant women with no SARS-CoV-2 infection in the first trimester were included in the control group. Mann Whitney U test, χ2 test, Fisher's exact probability method, and multivariate logistic regression were used to analyze the impact of SARS-CoV-2 infection on pregnancy outcomes during the first trimester.

RESULTS

A total of 30 cases in the study group experienced pregnancy loss before 28 weeks of gestation, and 468 cases delivered. In the control group, 41 cases experienced pregnancy loss before 28 weeks of gestation, and 613 cases delivered. The rates of pregnancy loss in the two groups were 6.02% and 6.27%, respectively, with no statistically significant difference between the two groups (P > 0.05). There was no statistically significant difference (P > 0.05) in the baseline data (delivery age, pre-pregnancy body mass index, gestational age, and parity) between the two groups. The rates of neonatal malformation, premature birth, premature rupture of membranes, postpartum hemorrhage, cesarean section, small for gestational age infants, low birth weight infants, macrosomia, and neonatal asphyxia were compared, with no statistically significant difference between the two groups (P > 0.05). However, the incidence of gestational hypertension in the study group was significantly higher than that in the control group (P = 0.012).

CONCLUSIONS

In this single center study, we found that SARS-CoV-2 infection in the first trimester may increase the risk of gestational hypertension, while the incidences of other adverse pregnant outcomes such as premature birth, premature rupture of membranes, cesarean section, postpartum hemorrhage, small for gestational age infants, low birth weight infants, and neonatal asphyxia did not significantly increase compared with women without SARS-CoV-2 infection in the first trimester.

Neurodevelopmental outcomes of infants after in utero exposure to SARS-CoV-2 or mRNA-COVID-19 vaccine compared with unexposed infants: a COVI-PREG prospective cohort study

OBJECTIVES

Data are lacking regarding the long-term consequences of SARS-CoV-2 and COVID-19 mRNA vaccine on infants exposed in utero. We aimed to evaluate the neurodevelopment of infants exposed prenatally to SARS-CoV-2 or mRNA-COVID-19 vaccine during pregnancy at 12 months after birth.

METHODS

Infants born to mothers exposed to SARS-CoV-2 or mRNA-COVID-19 vaccine during pregnancy, or unexposed to either the virus or the vaccine were enrolled from 2021 to 2023. Infants with prenatal exposure to the virus or vaccine were compared with infants without prenatal exposure to the virus and/or vaccine. Parents received a neurodevelopmental questionnaire (ages and stages questionnaire third edition) at 12 months after birth assessing five subdomains: communication, gross motor, fine motor, problem-solving, and personal social development. A low score was defined as <2 standard deviations below the normative mean in at least one of the subdomains.

RESULTS

A total of 330 infants were included (76 in the SARS-CoV-2 group, 153 in the mRNA-COVID-19 vaccine group, and 101 in the reference group). In utero exposure to the SARS-CoV-2 or mRNA-COVID-19 vaccine was not associated with an increased risk of a low score for at least one subdomain compared with the reference group. The crude ORs were 1.16 (95% CI, 0.59-2.28) and 1.04 (95% CI, 0.58-1.86), respectively. Results remained consistent in the multivariate analysis, showing no increased risk of a low score for at least one subdomain for infants exposed to the SARS-CoV-2 or mRNA-COVID-19 vaccine, compared with the reference group. The adjusted ORs were 1.74 (95% CI, 0.76-3.99) and 0.76 (95% CI, 0.39-1.49), respectively.

DISCUSSION

In utero exposure to SARS-CoV-2 or mRNA-COVID-19 vaccine was not associated with an increased risk of a low score for at least one ages and stages questionnaire third edition subdomain at 12 months after birth. Additional studies are needed to confirm our results, especially longer-term evaluation of infant development.

Association of SARS-CoV-2 Infection during pregnancy with placental weight and histopathologic lesions

INTRODUCTION

The reported gross and histopathologic changes in the placenta associated with SARS-CoV-2 infection are heterogeneous. We sought to summarize placental histopathologic findings from pregnancies affected by SARS-CoV-2 infection according to timing of infection and symptom severity.

METHODS

We conducted a retrospective cohort study of patients with SARS-CoV-2 infection during pregnancy who had deliveries at Mayo Clinic, Rochester, Minnesota, from April 2020 through June 2021. Placental histopathologic findings and clinical characteristics were compared for infections before vs after 28 weeks' gestation and according to COVID-19 symptom severity.

RESULTS

We analyzed 93 cases of SARS-CoV-2 infection during pregnancy, with 51 % of infections occurring before 28 weeks' gestation. Infections were categorized as asymptomatic (14 %), mild (77 %), moderate (6 %), and severe (3 %) according to World Health Organization criteria. An increased risk of small placental weight (<10th percentile) was associated with maternal infection at all gestational ages (30 %, P < .001). Histopathologic lesions consistent with maternal vascular malperfusion occurred more often for infections before than after 28 weeks' gestation (18/46, 38 % vs 9/47, 19 %; P = .047) and did not differ in frequency according to symptom severity. Inflammatory changes were present in 50 % of the placentas examined but did not differ by group, except that acute fetal vasculitis occurred more frequently after asymptomatic vs symptomatic maternal infection (23 % vs 5 %; risk ratio, 4.62; 95 % CI, 1.16-18.30).

DISCUSSION

COVID-19 at any gestational age or severity increases the risk of small placental weight and the presence of placental inflammatory lesions.

SARS-CoV-2 replicates in the placenta after maternal infection during pregnancy

Objectives

Pregnant women are at increased risk for severe SARS-CoV-2 infection and adverse neonatal outcome, primarily preterm birth and stillbirth. Our study aimed to investigate to which extent SARS-CoV-2 affects placental tissue and if viral replication within the placenta is evident, thus if there is a correlation between placental damage and adverse pregnancy outcome such as stillbirth.

Methods

We prospectively collected placentas from 61 SARS-CoV-2 infected pregnant women and 10 controls. Histopathological, immunohistochemical, and in situ hybridization studies were performed on all placentas with antibodies for SARS-CoV-2 proteins, ACE2, various immune cells, and inflammatory markers or probes for SARS-CoV-2 genes and an antisense strand.

Results

The measured scores of SARS-CoV-2 glycoprotein, nucleocapsid, and antisense strand indicating replication correlated with both the severity of maternal symptoms and presence of stillbirth. Specifically, 15/61 placentas exhibited replication, while the three cases with stillbirth had high or maximal replication scores. ACE2-H-score was significantly higher in COVID-19 patients, while the expression of various immune cells did not differ statistically. In multivariate analysis, presence of maternal comorbidities correlated with presence of severe COVID-19 infection.

Conclusion

We report evidence of active in vivo SARS-CoV-2 replication in the placenta after maternal infection in pregnancy in a case-control setting in a large population. Intensity of placental viral replication as well as viral levels were higher in women with severe or critical COVID-19 disease, supporting the rationale that severity of maternal SARS-CoV-2 infection could correlate with the severity of placentitis. Replication was maximal in cases of stillbirth, which suggests direct placental involvement in the pathophysiology of this dramatic outcome. Continuing to advocate for preventive measures against COVID-19 during pregnancy, including (re)vaccination, as well as appropriately counseling women with diagnosed infection, are of utter importance.

COVID-19 and obstetric outcomes: a single-center retrospective experience in a predominantly Black population

Objective: This retrospective, single-center case series was designed to characterize the effects of perinatal COVID-19 diagnosis on obstetric and neonatal outcomes in a predominantly high-risk, urban Black population.Study Design: Data were collected via retrospective chart review on all COVID-19-positive obstetric patients and their neonates who presented to the University of Chicago Medical Center between March 2020 and November 2020, before the availability of the COVID-19 vaccine. Patient demographics, delivery outcomes, COVID-19 symptoms, treatment, and outcomes were analyzed.Results: A total of 56 COVID-19-positive obstetric patients were included in the study, of which four were lost to follow-up before delivery. The median age of patients was 27 years (IQR 23, 32), with 73.2% publicly insured and 66.1% Black. Patients had a median body mass index (BMI) of 31.6 kg/m² (IQR 25.9, 35.5). 3.6% of patients had chronic hypertension, 12.5% had diabetes, and 16.1% had asthma. Perinatal complications were common. Twenty-six patients (50.0%) had a diagnosis of a hypertensive disorder of pregnancy (HDP). 28.8% had gestational hypertension, and 21.2% had preeclampsia (with and without severe features). The rate of maternal ICU admission was 3.6%. Furthermore, 23.5% of patients delivered preterm (<37 weeks gestation), and 50.9% of infants were admitted to the Neonatal Intensive Care Unit (NICU).Conclusion: In our study of a predominantly Black, publicly-insured, unvaccinated group of COVID-19-positive pregnant patients, we found high rates of hypertensive disorders of pregnancy, preterm delivery, and NICU admission compared to rates reported in existing literature before widespread vaccine availability. Our findings suggest that SARS-CoV-2 infection during pregnancy, irrespective of maternal disease severity, may exacerbate existing obstetric health disparities by disproportionately impacting Black, publicly insured patients. Larger comparative studies are needed to better characterize possible racial and socioeconomic disparities in obstetric outcomes in the setting of SARS-CoV-2 infection during pregnancy. These studies should examine the pathophysiology of SARS-CoV-2 infection during pregnancy, as well as potential associations between adverse perinatal outcomes and disparities in access to care, COVID-19 vaccination, and other social determinants of health amongst more vulnerable populations infected with SARS-CoV-2 during pregnancy.

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.

A History of COVID-19 in Pregnancy: A Narrative Review

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread across the world causing a global pandemic. During a pandemic, it becomes increasing important to evaluate the effects on specific populations at risk. In this narrative review, we analyzed the literature regarding COVID-19 infection on the pregnant population as they are at increased risk of infection. COVID-19 did seem to significantly increase the risk of obstetric complications, specifically in underserved and marginalized populations. In general, COVID-19 rarely directly infected the fetus and placenta, apart from a very rare complication called COVID placentitis. In actuality, the mothers were at greatest direct risk due to COVID-19 infection. The most important takeaway from this pandemic is the prospective lesson and effect it had on social determinants of health. Women did not have safe access to antenatal care, leading to a plethora of indirect obstetric complications due to COVID-19. In conclusion, it was women who suffered from the pandemic, not the placenta nor the fetus. It is our duty as physicians to protect pregnant women, allowing the placenta to protect the fetus.

Diverse mechanisms underlying the fetal growth course in gastroschisis and omphalocele

BACKGROUND

Gastroschisis and omphalocele are the 2 most common congenital fetal abdominal wall defects. Both malformations are commonly associated with small-for-gestational-age neonates. However, the extent and causes of growth restriction remain controversial in both gastroschisis and omphalocele without associated malformations or aneuploidy.

OBJECTIVE

This study aimed to examine the role of the placenta and the birthweight-to-placental weight ratio in fetuses with abdominal wall defects.

STUDY DESIGN

This study included all cases of abdominal wall defects examined at our hospital between January 2001 and December 2020, retrieving the data from the hospital's software. Fetuses with any other combined congenital anomalies, known chromosomal abnormalities, or lost to follow-up were excluded. Overall, 28 singleton pregnancies with gastroschisis and 24 singleton pregnancies with omphalocele met the inclusion criteria. Patient characteristics and pregnancy outcomes were reviewed. The primary outcome was to investigate the association between birthweight and placental weight in pregnancies with abdominal wall defects as measured after delivery. To correct for gestational age and to compare total placental weights, ratios between the observed and expected birthweights for the given gestational age in singletons were calculated. The scaling exponent β was compared with the reference value of 0.75. Statistical analysis was performed using GraphPad Prism (version 8.2.1; GraphPad Software, San Diego, CA) and IBM SPSS Statistics. A P value of <.05 indicated statistical significance.

RESULTS

Women pregnant with a fetus with gastroschisis were significantly younger and more often nulliparous. In addition, in this group, the gestational age of delivery was significantly earlier and almost exclusively for cesarean delivery. Of 28 children, 13 (46.7%) were born small for gestational age, only 3 of them (10.7%) had a placental weight <10th percentile. There is no correlation between birthweight percentiles and placental weight percentiles (P=not significant). However, in the omphalocele group, 4 of 24 children (16.7%) were born small for gestational age (<10th percentile), and all children also had a placental weight <10th percentile. There is a significant correlation between birthweight percentiles and placental weight percentiles (P<.0001). The birthweight-to-placental weight ratio differs significantly between pregnancies diagnosed with gastroschisis and pregnancies diagnosed with omphalocele (4.48 [3.79-4.91] vs 6.05 [5.38-6.47], respectively; P<.0001). Allometric metabolic scaling revealed that placentas complicated by gastroschisis and placentas complicated by omphalocele do not scale with birthweight.

CONCLUSION

Fetuses with gastroschisis displayed impaired intrauterine growth, which seemed to differ from the classical placental insufficiency growth restriction.

An Update on COVID-19 Vaccination and Pregnancy

Pregnant women are more prone to experience severe COVID-19 disease, including intensive care unit (ICU) admission, use of invasive ventilation, extracorporeal membrane oxygenation (ECMO), and mortality compared to non-pregnant individuals. Additionally, research suggests that SARS-CoV-2 infection during pregnancy is linked to adverse pregnancy outcomes, such as preterm birth, preeclampsia, and stillbirth, as well as adverse neonatal outcomes, including hospitalization and admission to the neonatal intensive care unit. This review assessed the available literature from November 2021 to 19 March 2023, concerning the safety and effectiveness of COVID-19 vaccination during pregnancy. COVID-19 vaccination administered during pregnancy is not linked to significant adverse events related to the vaccine or negative obstetric, fetal, or neonatal outcomes. Moreover, the vaccine has the same effectiveness in preventing severe COVID-19 disease in pregnant individuals as in the general population. Additionally, COVID-19 vaccination is the safest and most effective method for pregnant women to protect themselves and their newborns from severe COVID-19 disease, hospitalization, and ICU admission. Thus, vaccination should be recommended for pregnant patients. While the immunogenicity of vaccination in pregnancy appears to be similar to that in the general population, more research is needed to determine the optimal timing of vaccination during pregnancy for the benefit of the neonate.

SARS-CoV-2 in Pregnancy, Birth and Puerperium. Guideline of the DGGG and DGPM (S2k-Level, AWMF Registry Number 015/092, March 2022)

Objective This S2k guideline of the German Society for Gynecology and Obstetrics (DGGG) and the German Society of Perinatal Medicine (DGPM) contains consensus-based recommendations for the care and treatment of pregnant women, parturient women, women who have recently given birth, and breastfeeding women with SARS-CoV-2 infection and their newborn infants. The aim of the guideline is to provide recommendations for action in the time of the COVID-19 pandemic for professionals caring for the above-listed groups of people. Methods The PICO format was used to develop specific questions. A systematic targeted search of the literature was carried out using PubMed, and previously formulated statements and recommendations issued by the DGGG and the DGPM were used to summarize the evidence. This guideline also drew on research data from the CRONOS registry. As the data basis was insufficient for a purely evidence-based guideline, the guideline was compiled using an S2k-level consensus-based process. After summarizing and presenting the available data, the guideline authors drafted recommendations in response to the formulated PICO questions, which were then discussed and voted on. Recommendations Recommendations on hygiene measures, prevention measures and care during pregnancy, delivery, the puerperium and while breastfeeding were prepared. They also included aspects relating to the monitoring of mother and child during and after infection with COVID-19, indications for thrombosis prophylaxis, caring for women with COVID-19 while they are giving birth, the presence of birth companions, postnatal care, and testing and monitoring the neonate during rooming-in or on the pediatric ward.

Infectious and environmental placental insults: from underlying biological pathways to diagnostics and treatments

Because the placenta is bathed in maternal blood, it is exposed to infectious agents and chemicals that may be present in the mother's circulation. Such exposures, which do not necessarily equate with transmission to the fetus, may primarily cause placental injury, thereby impairing placental function. Recent research has improved our understanding of the mechanisms by which some infectious agents are transmitted to the fetus, as well as the mechanisms underlying their impact on fetal outcomes. However, less is known about the impact of placental infection on placental structure and function, or the mechanisms underlying infection-driven placental pathogenesis. Moreover, recent studies indicate that noninfectious environmental agents accumulate in the placenta, but their impacts on placental function and fetal outcomes are unknown. Critically, diagnosing placental insults during pregnancy is very difficult and currently, this is possible only through postpartum placental examination. Here, with emphasis on humans, we discuss what is known about the impact of infectious and chemical agents on placental physiology and function, particularly in the absence of maternal-fetal transmission, and highlight knowledge gaps with potential implications for diagnosis and intervention against placental pathologies.

Functional consequences of SARS-CoV-2 infection in pregnant women, fetoplacental unit, and neonate

The SARS-CoV-2 infection causes COVID-19 disease, characterized by acute respiratory distress syndrome, bilateral pneumonia, and organ failure. The consequences of maternal SARS-CoV-2 infection for the pregnant woman, fetus, and neonate are controversial. Thus, it is required to determine whether there is viral and non-viral vertical transmission in COVID-19. The disease caused by SARS-CoV-2 leads to functional alterations in asymptomatic and symptomatic pregnant women, the fetoplacental unit and the neonate. Several diseases of pregnancy, including COVID-19, affect the fetoplacental function, which causes in utero programming for young and adult diseases. A generalized inflammatory state and a higher risk of infection are seen in pregnant women with COVID-19. Obesity, diabetes mellitus, and hypertension may increase the vulnerability of pregnant women to infection by SARS-CoV-2. Alpha, Delta, and Omicron variants of SARS-CoV-2 show specific mutations that seem to increase the capacity of the virus to infect the pregnant woman, likely due to increasing its interaction via the virus S protein and angiotensin-converting enzyme 2 receptors. This review shows the literature addressing to what extent COVID-19 in pregnancy affects the pregnant woman, fetoplacental unit, and neonate. Prospective studies that are key in managing SARS-CoV-2 infection in pregnancy are discussed.

Gestational diabetes is associated with SARS-CoV-2 infection during pregnancy: A case-control study

Aim

Individuals with SARS-CoV-2 infection and (pre-existing) diabetes, including pregnant women, present with more severe morbidity, as compared to non-diabetic subjects. To date, evidence is limited concerning the role of gestational diabetes (GDM) in severity of SARS-CoV-2 infection during pregnancy, or vice versa. The aim of our study was to investigate the prevalence of GDM in a SARS-CoV-2 infected pregnant population and evaluate risk factors for and from severe infection in these patients.

Methods

A case-control study with prospective data collection for the case group and 1:2 matching with historical controls based on parity, BMI and ethnicity was conducted (n = 224). GDM screening was performed at 26 weeks’ gestation. Multivariate binary logistic regression analysis was performed to assess risk factors for GDM and inpatient COVID-19 management.

Results

34.6% of the patients in the case group suffered from GDM, vs. 16.1% in the control group (p = 0.002). 35.7% patients were diagnosed with GDM after, vs. 33.3% before SARS-CoV-2 infection (OR (95%CI) 1.11(0.40–3.08), p = 0.84), with no correlation between time point of infection and GDM diagnosis. SARS-CoV-2 (OR (95%CI) 2.79 (1.42, 5.47), p = 0.003) and BMI (OR (95%CI) 1.12 (1.05, 1.19), p = 0.001) were significant independent risk factors for GDM.

Conclusion

Data suggests that GDM increases the risk of infection in SARS-CoV-2 infected pregnant women. Meanwhile, SARS-CoV-2 during pregnancy might increase the risk of developing GDM.

Vaccination and caution in using protective measures should be recommended to pregnant women, particularly when suffering from GDM.