The impact of influenza virus infection in pregnancy

Knowledge, attitudes, and perceptions of influenza vaccine among pregnant women in Minhang District, Shanghai

This study aimed to assess the attitudes and willingness of pregnant women to receive the influenza vaccine and the factors influencing their decisions. A sample survey was conducted among pregnant women receiving prenatal care at various medical institutions in Minhang District, Shanghai, from March to June 2023. The survey included inquiries about demographic information, knowledge, and perception of influenza disease and influenza vaccine. Logistic regression models and chi-square tests were used to analyze the data. 6.9% (78/1125) of participants considered receiving the influenza vaccine during pregnancy. Participants with graduate education or above (OR = 4.632, 95%CI: 1.046-20.517), non-office workers (OR = 2.784, 95%CI: 1.560-4.970), and participants whose spouses were not office workers (OR = 0.518, 95% CI: 0.294-0.913) were significantly associated with high intent to vaccinate. Participants with superior knowledge (>30 points) exhibited greater willingness (p < .001). Participants who viewed post-influenza symptoms as mild had a significantly lower willingness to vaccinate during pregnancy (2.3%), compared to those who disagreed (p = .015). Conversely, those recognizing a heightened risk of hospitalization due to respiratory diseases in pregnant women post-influenza were significantly more inclined to vaccinate during pregnancy (8.8%) (p = .007). Participants recognizing benefits uniformly expressed willingness to receive the influenza vaccine during pregnancy (p < .001), while those perceiving barriers uniformly rejected vaccination (p < .001). Higher education, non-office worker status, and having an office worker spouse correlate with greater willingness to receive the influenza vaccine during pregnancy. Enhanced knowledge and accurate perceptions of influenza and its vaccine influenced willingness. Accumulating knowledge about influenza and its vaccine fosters accurate perceptions. Notably, overall willingness to vaccinate during pregnancy remains low, likely due to safety concerns, and lack of accurate perceptions. Targeted health education, improved communication between healthcare providers and pregnant women, and campaigns highlighting vaccine benefits for mothers and children are essential.

Immunometabolic adaptation in monocytes underpins functional changes during pregnancy

Metabolic heterogeneity is a determinant of immune cell function. The normal physiological metabolic reprogramming of pregnancy that ensures the fuel requirements of mother and baby are met, might also underpin changes in immunity that occur with pregnancy and manifest as altered responses to pathogens and changes to autoimmune disease symptoms. Using peripheral blood from pregnant women at term, we reveal that monocytes lose M2-like and gain M1-like properties accompanied by reductions in mitochondrial mass, maximal respiration, and cardiolipin content in pregnancy; glycolysis is unperturbed. We establish that muramyl dipeptide (MDP)-stimulated cytokine production relies on oxidative metabolism, then show in pregnancy reduced cytokine production in response to MDP but not LPS. Overall, mitochondrially centered metabolic capabilities of late gestation monocytes are down-regulated revealing natural plasticity in monocyte phenotype and function that could reveal targets for improving pregnancy outcomes but also yield alternative therapeutic approaches to diverse metabolic and/or immune-mediated diseases beyond pregnancy.

Attitude to Co-Administration of Influenza and COVID-19 Vaccines among Pregnant Women Exploring the Health Action Process Approach Model

Respiratory tract diseases caused by influenza virus and SARS-CoV-2 can represent a serious threat to the health of pregnant women. Immunological remodulation for fetus tolerance and physiological changes in the gestational chamber expose both mother and child to fearful complications and a high risk of hospitalization. Vaccines to protect pregnant women from influenza and COVID-19 are strongly recommended and vaccine co-administration could be advantageous to increase coverage of both vaccines. The attitude to accept both vaccines is affected by several factors: social, cultural, and cognitive-behavioral. In Palermo, Italy, during the 2021-2022 influenza season, a cross-sectional study was conducted to evaluate pregnant women's intention to adhere to co-administration of influenza and COVID-19 vaccines. The determinants of vaccination attitude were investigated through the administration of a questionnaire and the Health Action Process Approach theory was adopted to explore the cognitive behavioral aspects. Overall, 120 pregnant women were enrolled; mean age 32 years, 98.2% (n = 118) of Italian nationality and 25.2% (n = 30) with obstetric or pathological conditions of pregnancy at risk. Factors significantly associated with the attitude to co-administration of influenza and COVID-19 vaccines among pregnant women were: high level of education (OR = 13.96; p < 0.001), positive outcome expectations (OR = 2.84; p < 0.001), and self-efficacy (OR = 3.1; p < 0.001). Effective strategies to promote the co-administration of the influenza vaccine and the COVID-19 vaccine should be based on the communication of the benefits and positive outcomes of vaccine co-administration and on the adequate information of pregnant women.

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.

Pregnant women's attitudes and behaviours towards antenatal vaccination against Influenza and COVID-19 in the Liverpool City Region, United Kingdom: Cross-sectional survey

Objectives

Influenza poses a serious health risk to pregnant women and their babies. Despite this risk, influenza vaccine uptake in pregnant women in the UK is less than 50%. Little is known about how COVID-19 affects pregnant women, but its management may affect attitudes and behaviours towards vaccination in pregnancy. The study objectives were to establish attitudes and knowledge of pregnant women towards influenza disease and influenza vaccination and to compare these to attitudes and knowledge about COVID-19 and COVID-19 vaccination.

Design

A cross-sectional survey was conducted using an online questionnaire distributed through local advertisement and social media outlets. Information was sought on attitudes and knowledge of influenza and COVID-19 and their respective vaccines.

Participants and setting

Pregnant women residing in Liverpool City Region, UK.

Results

Of the 237 respondents, 73.8% reported receiving an influenza vaccine. Over half (56.5%) perceived themselves to be at risk from influenza, 70.5% believed that if they got influenza, their baby would get ill, and 64.6% believed getting influenza could hurt their baby, 60.3% believed that the influenza vaccine would prevent their baby from getting ill, and 70.8% believed it would protect their baby. Only 32.9% of respondents stated they would receive the COVID-19 vaccine if it were available to them. However, 80.2% stated they would receive a COVID-19 vaccine if they were not pregnant. Most of the women stated that they would accept a vaccine if recommended to them by healthcare professionals.

Conclusions

Acceptance of the influenza and COVID-19 vaccines during pregnancy seems to be more related to the safety of the baby rather than the mother. Women perceived their child to be more at risk than themselves. Information about influenza and COVID-19 vaccine safety as well as healthcare provider recommendations play an important role in vaccine uptake in pregnant women.

Evaluation of Maternal and Fetal Outcomes in Pregnant Women with COVID-19 based on Different Trimesters

Background

COVID-19 is the leading cause of the recent pandemic in the globe. This disease might have different effects on the maternal and fetal outcomes in pregnancy. The aim of this study was to assess these outcomes in pregnant women with COVID-19 infections in different trimesters.

Materials and Methods

This is a prospective cohort study that was performed in February 2020 to August 2021 in Isfahan on 430 pregnant women with definite diagnosis of COVID-19 infection admitted to our medical centers. The included cases were followed based on the gestational age in which they were diagnosed with COVID-19 infection. Patients were divided into three groups (first, second, and third trimesters) based on COVID-19 infection.

Results

The frequency of requiring mechanical ventilation was higher in mothers with COVID-19 in the second trimester (P = 0.049) and the frequency of PIH was significantly higher in mothers with COVID-19 in the third trimester compared to other women (P = 0.009). Fetal growth restriction (FGR) was also observed in 22 patients (5.3%) that was mostly observed with COVID-19 in the third trimester (P = 0.012). Oligohydramnios and fetal distress leading to C/S were observed in 19 patients (4.6%) and 12 patients (2.9%), respectively. The majority of maternal mortality was among cases with COVID-19 infection in the third trimester (44.4%).

Conclusion

We observed higher maternal and fetal complications in women especially those in the third trimester. Our results were in line with the findings of previous studies. Women with COVID-19 infection in the third trimester had highest frequencies of preterm labor and FGR.

Trends and inequities in severe maternal morbidity in Massachusetts: A closer look at the last two decades

It is estimated that 50,000-60,000 pregnant people in the United States (US) experience severe maternal morbidity (SMM). SMM includes life-threatening conditions, such as acute myocardial infarction, acute renal failure, amniotic fluid embolism, disseminated intravascular coagulation, or sepsis. Prior research has identified both rising rates through 2014 and wide racial disparities in SMM. While reducing maternal death and SMM has been a global goal for the past several decades, limited progress has been made in the US in achieving this goal. Our objectives were to examine SMM trends from 1998-2018 to identify factors contributing to the persistent and rising rates of SMM by race/ethnicity and describe the Black non-Hispanic/White non-Hispanic rate ratio for each SMM condition. We used a population-based data system that links delivery records to their corresponding hospital discharge records to identify SMM rates (excluding transfusion) per 10, 000 deliveries and examined the trends by race/ethnicity. We then conducted stratified analyses separately for Black and White birthing people. While the rates of SMM during the same periods steadily increased for all racial/ethnic groups, Black birthing people experienced the greatest absolute increase compared to any other race/ethnic group going from 69.4 in 1998-2000 to 173.7 per 10,000 deliveries in 2016-2018. In addition, we found that Black birthing people had higher rates for every individual condition compared to White birthing people, with rate ratios ranging from a low of 1.11 for heart failure during surgery to a high of 102.4 for sickle cell anemia. Obesity was not significantly associated with SMM among Black birthing people but was associated with SMM among White birthing people [aRR 1.18 (95% CI: 1.02, 1.36)]. An unbiased understanding of how SMM has affected different race/ethnicity groups is key to improving maternal health and preventing SMM and mortality among Black birthing people. SMM needs to be addressed as both a medical and public health challenge.

Influenza Virus Infection during Pregnancy as a Trigger of Acute and Chronic Complications

Influenza A virus (IAV) infection during pregnancy disrupts maternal and fetal health through biological mechanisms, which are to date poorly characterised. During pregnancy, the viral clearance mechanisms from the lung are sub-optimal and involve hyperactive innate and adaptive immune responses that generate wide-spread inflammation. Pregnancy-related adaptations of the immune and the cardiovascular systems appear to result in delayed recovery post-viral infection, which in turn promotes a prolonged inflammatory phenotype, increasing disease severity, and causing maternal and fetal health problems. This has immediate and long-term consequences for the mother and fetus, with complications including acute cardiopulmonary distress syndrome in the mother that lead to perinatal complications such as intrauterine growth restriction (IUGR), and birth defects; cleft lip, cleft palate, neural tube defects and congenital heart defects. In addition, an increased risk of long-term neurological disorders including schizophrenia in the offspring is reported. In this review we discuss the pathophysiology of IAV infection during pregnancy and its striking similarity to other well-established complications of pregnancy such as preeclampsia. We discuss general features of vascular disease with a focus on vascular inflammation and define the "Vascular Storm" that is triggered by influenza infection during pregnancy, as a pivotal disease mechanism for short and long term cardiovascular complications.

Clinical characteristics and risk factors for maternal deaths due to COVID-19 in Brazil: a nationwide population-based cohort study

BACKGROUND

Monitoring the characteristics and associated factors for death among pregnant and postpartum women with coronavirus disease 19 (COVID-19) is necessary. We investigated the clinical characteristics and risk factors associated with maternal deaths in a nationwide cohort of Brazil.

METHODS

This was a population-based cohort of all pregnant and postpartum women hospitalised with COVID-19 notified to the Sistema de Informação de Vigilância Epidemiológica da Gripe of Brazil (SIVEP-Gripe), from February 2020 to September 2021. The primary outcome was time to in-hospital death, with risk factors analysed with univariable and multivariable Cox proportional hazards regression models.

RESULTS

Cumulative observation time was 248 821 person-days from hospital admission to the end of follow-up for 15 105 individuals. There were 1858 deaths (12.3%) for a maternal mortality rate of 7.5 (95% CI 7.1-7.8) per 1000 patients-days. The cumulative mortality increased over time. Black/Brown ethnicity had a higher risk of death than women self-identifying as White. Women in the North, Northeast, Central-West and Southeast regions had higher risk of death than women in the South region. The characteristics independently associated with death were a postpartum status on admission [adjusted hazard ratio, HR 1.4 (95% confidence interval, CI 1.2-1.6)], pre-existing clinical conditions [adjusted HRs 1.2 (95%CI 1.1-1.3) for one and 1.3 (95%CI 1.1-1.5) for two comorbidities], hypoxaemia on admission [adjusted HR 1.2 (95%CI 1.1-1.4)] and requiring non-invasive [adjusted HR 2.6 (95%CI 2.1-3.3)] or invasive ventilatory support [adjusted HR 7.1 (95%CI 5.6-9.2)].

CONCLUSION

In Brazil, the in-hospital maternal mortality rate due to COVID-19 is high and the risk of death increases with the length of hospitalisation. Socio-demographic and biological factors are associated with an increased risk of maternal death. The presence of respiratory signs and symptoms should be considered early markers of disease severity and an adequate management is necessary. Our findings reinforce the need for vaccination of pregnant and postpartum women against COVID-19.

Measuring Evidence-Based Viral Respiratory Illness Mitigation Behaviors in Pregnant Populations: Development and Validation of a Short, Single-Factor Scale During the COVID-19 Pandemic

OBJECTIVE

Researchers and public health professionals need to better understand individual engagement in coronavirus disease 2019 (COVID-19) mitigation behaviors to reduce the human and societal costs of the current pandemic and prepare for future respiratory pandemics. We suggest that developing measures of individual mitigation behaviors and testing them among high-risk individuals, including pregnant people, may help to reduce overall morbidity and mortality by quickly identifying targets for messaging around mitigation until sufficient vaccination uptake is reached.

METHODS

We surveyed pregnant people in California over 2 waves of the COVID-19 pandemic to explore mitigation behaviors. We developed and validated a novel Viral Respiratory Illness Mitigation Scale (VRIMS).

RESULTS

Seven measures loaded onto a single factor with good psychometric properties. The overall sample scale average was high over both waves, indicating that most pregnant Californians engaged in most of the strategies most of the time. Older participants, minoritized participants, those living in more urban contexts, and those surveyed during a surge reported engaging in these strategies most frequently.

CONCLUSIONS

Clinicians and researchers should consider using reliable, validated measures like the VRIMS to identify individuals and communities that may benefit from additional education on reducing risk for COVID-19, future respiratory pandemics, or even seasonal flu.

Consequences of Viral Infection and Cytokine Production During Pregnancy on Brain Development in Offspring

Infections during pregnancy can seriously damage fetal neurodevelopment by aberrantly activating the maternal immune system, directly impacting fetal neural cells. Increasing evidence suggests that these adverse impacts involve alterations in neural stem cell biology with long-term consequences for offspring, including neurodevelopmental disorders such as autism spectrum disorder, schizophrenia, and cognitive impairment. Here we review how maternal infection with viruses such as Influenza A, Cytomegalovirus, and Zika during pregnancy can affect the brain development of offspring by promoting the release of maternal pro-inflammatory cytokines, triggering neuroinflammation of the fetal brain, and/or directly infecting fetal neural cells. In addition, we review insights into how these infections impact human brain development from studies with animal models and brain organoids. Finally, we discuss how maternal infection with SARS-CoV-2 may have consequences for neurodevelopment of the offspring.

Impact of major disease outbreaks in the third millennium on adolescent and youth sexual and reproductive health and rights in low and/or middle-income countries: a systematic scoping review protocol

INTRODUCTION

Sexual and Reproductive Health and Rights (SRHR) of young people continue to present a high burden and remain underinvested. This is more so in low and middle-income countries (LMICs), where empirical evidence reveals disruption of SRHR maintenance, need for enhancement of programmes, resources and services during pandemics. Despite the importance of the subject, there is no published review yet combining recent disease outbreaks such as (H1N1/09, Zika, Ebola and SARS-COV-2) to assess their impact on adolescents and youth SRHR in LMICs.

METHODS AND ANALYSIS

We will adopt a four-step search to reach the maximum possible number of studies. In the first step, we will carry out a limitedpreliminary search in databases for getting relevant keywords (appendix 1). Second, we will search in four databases: Pubmed, Cochrane Library, Embase and PsycINFO. The search would begin from the inception of the first major outbreak in 2009 (H1N1/09) up to the date of publication of the protocol in early 2022. We will search databases using related keywords, screen title & abstract and review full texts of the selected titles to arrive at the list of eligible studies. In the third stage, we will check their eligibility to the included article's reference list. In the fourth stage, we will check the citations of included papers in phase 2 to complete our study selection. We will include all types of original studies and without any language restriction in our final synthesis. Our review results will be charted for each pandemic separately and include details pertaining to authors, year, country, region of the study, study design, participants (disaggregated by age and gender), purpose and report associated SRHR outcomes. The review will adhere to the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews guideline (PRISMA-ScR).

PATIENT AND PUBLIC INVOLVEMENT

Patients or public were not involved in this study.

ETHICS AND DISSEMINATION

Ethical assessment is not required for this study. The results of the study will be presented in peer-reviewed publications and conferences on adolescent SRHR.

Molecular and Physiological Aspects of SARS-CoV-2 Infection in Women and Pregnancy

Whilst scientific knowledge about SARS-CoV-2 and COVID-19 is rapidly increasing, much of the effects on pregnant women is still unknown. To accommodate pregnancy, the human endometrium must undergo a physiological transformation called decidualization. These changes encompass the remodeling of endometrial immune cells leading to immunotolerance of the semi-allogenic conceptus as well as defense against pathogens. The angiotensin converting enzyme 2 (ACE2) plays an important regulatory role in the renin-angiotensin-system (RAS) and has been shown to be protective against comorbidities known to worsen COVID-19 outcomes. Furthermore, ACE2 is also crucial for decidualization and thus for early gestation. An astounding gender difference has been found in COVID-19 with male patients presenting with more severe cases and higher mortality rates. This could be attributed to differences in sex chromosomes, hormone levels and behavior patterns. Despite profound changes in the female body during pregnancy, expectant mothers do not face worse outcomes compared with non-pregnant women. Whereas mother-to-child transmission through respiratory droplets during labor or in the postnatal period is known, another question of in utero transmission remains unanswered. Evidence of placental SARS-CoV-2 infection and expression of viral entry receptors at the maternal-fetal interface suggests the possibility of in utero transmission. SARS-CoV-2 can cause further harm through placental damage, maternal systemic inflammation, and hindered access to health care during the pandemic. More research on the effects of COVID-19 during early pregnancy as well as vaccination and treatment options for gravid patients is urgently needed.

Clinical characteristics and viral analysis of severe influenza A [H1N1]pdm09 in Guangzhou, 2019

OBJECTIVE

To understand the clinical characteristics of and analyze viral genes in patients with severe pneumonia due to [H1N1]pdm09 influenza virus in Guangzhou, 2019.

METHODS

The clinical data of 120 inpatients with laboratory-confirmed influenza A H1N1 virus from January to March 2019 were collected and analyzed. The subjects were diagnosed according to the criteria of the "Diagnosis and Treatment Program of Influenza A H1N1 (third Edition 2009)" issued by the Ministry of Health and were divided into severe and nonsevere groups. Serum samples during fever were collected for cytokine analysis, and the viral genes were analyzed after the virus cultured in MDCK cells. The data were analyzed by SPSS 16 software, and the results of gene sequencing were analyzed by MEGA 6 software.

RESULTS

Among the 120 inpatients, 36 (30%) were severe and 84 (70%) were nonsevere patients. The average age of severe patients was 53.11 ±19.94 years, the average age of nonsevere patients, at 44.03 ±24.47 years. There was no significant difference between the two groups (p< 0.05). There were significant differences in the rates of moist rales and dyspnea in critically ill patients (p< 0.05). There were significant differences in the white blood cell count (WBC), lactate dehydrogenase (LDH), creatine kinase (CK), serum creatinine (sCr), procalcitonin (PCT) and C-reactive protein (CRP) in severe patients with type A H1N1. Chest radiologic findings in severe patients showed ground glass shadows or pulmonary solid changes, and the difference was statistically significant for pulmonary fibrosis. Chronic lung disease (52.8%) and cardiovascular disease (27.8%) were independent risk factors for severe disease (p< 0.05). There were significant differences in secondary infections by Staphylococcus aureus (11.1%), pulmonary Aspergillus (22%) and Acinetobacter baumannii (16.7%) in critically ill patients (p< 0.05). Serum IL-8 in critically ill patients was significantly higher than those in nonsevere patients and healthy controls. The origin of virus strains in severe and nonsevere patients was the same, and there was no obvious mutation in the amino acid region of the antigenic site of the HA protein, but compared with the results of gene sequencing in previous years, the mutation sites showed a trend of annual accumulation. In conclusion, there was a high risk of severe pneumonia caused by H1N1 influenza A virus in Guangzhou in spring 2019. Long-term continuous surveillance, prevention and control of the virus should be carried out to predict its epidemiology and distribution. This article is protected by copyright. All rights reserved.

Views and experiences of maternal healthcare providers regarding influenza vaccine during pregnancy globally: A systematic review and qualitative evidence synthesis

BACKGROUND

The World Health Organization (WHO) recommends that pregnant women receive influenza vaccination; however, uptake of the vaccine remains low. Maternity health care professionals (MHCPs) play an important role in motivating pregnant women to receive the influenza vaccine. However, factors such as MHCPs' views and knowledge about the vaccine, and time constraints due to workload may influence MHCPs' practices and opinions about women receiving the influenza vaccine during pregnancy. To date, the qualitative evidence exploring MHCPs' views and experiences around influenza vaccine uptake in pregnant women has not been synthesised.

AIM

To systematically review and thematically synthesise qualitative evidence that explores the views and experiences of MHCPs involved in the provision of the maternal influenza vaccine worldwide.

METHODS

Five databases (MEDLINE, EMBASE, PsycINFO, CINAHL, Web of Science) were searched, supplemented with searches of included paper reference lists and grey literature. Study selection was conducted by up to three researchers applying pre-specified inclusion/exclusion criteria. Quality assessment was undertaken, data were extracted, coded and synthesised to develop descriptive and analytical themes.

RESULTS

Eight studies involving 277 participants were included. Seventeen descriptive themes were interpreted, embedded within six analytical themes. MHCPs perceived that maternal influenza vaccination delivery can be facilitated by trusting relationships, good communication, knowledge about the vaccine leading to confidence in recommending vaccine, electronic vaccination prompts, and presence of national guidelines. However, workload, time constraints, MHCP's perception of pregnant women's concerns, and social/cultural/environmental influences could prevent the likelihood of delivery of influenza vaccine. Knowledgeable MHCPs who were regularly updated about vaccination based on scientific evidence were more confident when discussing and recommending the influenza vaccine to pregnant women. In addition, the presence of national policies and guidelines and electronic prompts for maternal influenza vaccination would enhance the delivery of the vaccine.

CONCLUSION

Our findings suggest that approaches to enhance the vaccination uptake rate in pregnant women include addressing MHCPs barriers to discussing influenza vaccination through education, sufficient time for discussions, and electronic prompts about vaccination, as well as evidence based local and national guidelines.

Viral Infections During Pregnancy: The Big Challenge Threatening Maternal and Fetal Health

Viral infections during pregnancy are associated with adverse pregnancy outcomes, including maternal and fetal mortality, pregnancy loss, premature labor, and congenital anomalies. Mammalian gestation encounters an immunological paradox wherein the placenta balances the tolerance of an allogeneic fetus with protection against pathogens. Viruses cannot easily transmit from mother to fetus due to physical and immunological barriers at the maternal-fetal interface posing a restricted threat to the fetus and newborns. Despite this, the unknown strategies utilized by certain viruses could weaken the placental barrier to trigger severe maternal and fetal health issues especially through vertical transmission, which was not fully understood until now. In this review, we summarize diverse aspects of the major viral infections relevant to pregnancy, including the characteristics of pathogenesis, related maternal-fetal complications, and the underlying molecular and cellular mechanisms of vertical transmission. We highlight the fundamental signatures of complex placental defense mechanisms, which will prepare us to fight the next emerging and re-emerging infectious disease in the pregnancy population.

Morbidity of late-season influenza during pregnancy

BACKGROUND

In the Northern Hemisphere, influenza season typically starts in December and lasts through March. Pregnant people are at increased risk for influenza-related morbidity and mortality. Potentially, new viral strains or reduced provider suspicion leading to delayed diagnosis of late-season influenza could result in an increased risk of severe infection.

OBJECTIVE

This study aimed to assess the incidence and morbidity associated with late-season influenza in pregnancy, compared with influenza in other seasons.

STUDY DESIGN

This was a retrospective cohort study using the 2007-2018 National Inpatient Sample. Pregnant patients with discharge diagnosis codes consistent with influenza infection were compared on the basis of hospital admission quarter (quarter 1: October to December; quarter 2: January to March; quarter 3: April to June; quarter 4: July to September), with quarter 3 defined as "late-season." The primary outcome was the severe maternal morbidity composite defined by the Centers for Disease Control and Prevention. The secondary outcomes included sepsis, shock, acute renal failure, acute heart failure, temporary tracheostomy, and invasive mechanical ventilation. Associations between outcomes and quarter of infection were adjusted for age, hospitalization type (antepartum, delivery, or postpartum), and comorbid conditions using relative risk regression, weighted to reflect the National Inpatient Sample design.

RESULTS

Of 7355 hospitalizations, corresponding to a weighted national estimate of 36,042, 2266 (30.8%) occurred in quarter 1, 4051 (55.0%) in quarter 2, 633 (8.6%) in quarter 3, and 405 (5.5%) in quarter 4. A nonsignificant trend toward higher rates of severe maternal morbidity was seen in the "late-season" compared with other quarters (13.9% [quarter 3] vs 10.5% [quarter 1] vs 12.1% [quarter 2] vs 13.6% [quarter 4]; P=.07). Moreover, sepsis was more common in patients with late-season influenza (8.0% [quarter 3] vs 4.8% [quarter 1] vs 5.8% [quarter 2] vs 5.9% [quarter 4]; P=.03). In the adjusted analyses, patients with late-season influenza had a 1.34 (95% confidence interval, 1.01-1.78) higher risk of severe maternal morbidity and 1.57 (95% confidence interval, 1.06-2.32) higher risk of sepsis than patients with influenza in quarter 1.

CONCLUSION

Influenza infection between April and June, that is, late-season influenza, is associated with a higher risk of severe maternal morbidity and sepsis in pregnant patients. Obstetrical providers must continue to have awareness and suspicion for influenza infection during these months.

Potential Neurocognitive Symptoms Due to Respiratory Syncytial Virus Infection

Respiratory infections are among the major public health burdens, especially during winter. Along these lines, the human respiratory syncytial virus (hRSV) is the principal viral agent causing acute lower respiratory tract infections leading to hospitalization. The pulmonary manifestations due to hRSV infection are bronchiolitis and pneumonia, where the population most affected are infants and the elderly. However, recent evidence suggests that hRSV infection can impact the mother and fetus during pregnancy. Studies have indicated that hRSV can infect different cell types from the placenta and even cross the placenta barrier and infect the fetus. In addition, it is known that infections during the gestational period can lead to severe consequences for the development of the fetus due not only to a direct viral infection but also because of maternal immune activation (MIA). Furthermore, it has been described that the development of the central nervous system (CNS) of the fetus can be affected by the inflammatory environment of the uterus caused by viral infections. Increasing evidence supports the notion that hRSV could invade the CNS and infect nervous cells, such as microglia, neurons, and astrocytes, promoting neuroinflammation. Moreover, it has been described that the hRSV infection can provoke neurological manifestations, including cognitive impairment and behavioral alterations. Here, we will review the potential effect of hRSV in brain development and the potential long-term neurological sequelae.

Impact of emerging virus pandemics on cause-specific maternal mortality time series: a population-based natural experiment using national vital statistics, Argentina 1980-2017

Background

Emerging pandemic viruses may have multiple deleterious effects on maternal health. This study examines the effects of a pandemic influenza virus on cause-specific maternal mortality time series, using Argentinian vital statistics.

Methods

We conducted a population-based natural experiment from national vital records of maternal deaths between 1980 and 2017. Joinpoint regression models were used to model time series of the maternal mortality ratio (MMR). The sensitivity of the registry to detect the effects of the pandemic H1N1 2009 influenza virus on cause-specific MMR was analysed using a panel of parallel interrupted time series (ITS).

Findings

Over this 38-year study, the MMR decreased by 58·6% (69·5 to 28·8 deaths/100,000 live births), transitioning from direct obstetric causes (67·0 to 21·1/100,000 live births; 68·4% decrease) to indirect causes (2·6 to 7·7/100,000 live births; 196·2% increase). The regression analysis showed an average reduction of -2·2%/year (95% CI: -2·9 to -1·4) with 2 join points in the total trend (1998 and 2009). Parallel ITS analyses revealed the pandemic H1N1 virus had an increasing effect on mortality from the respiratory system- and sepsis-related complications (level change 4·7 and 1·6/100,000 live births respectively), reversing after the outbreak. No effect was found on MMR from hypertensive disorders, haemorrhage, abortive outcomes, other direct obstetric causes, and indirect non-respiratory comorbidities.

Interpretation

The Argentinian maternal death registry appears sensitive to detect different effects of emerging infectious epidemics on maternal health. In a population-based natural experiment, pandemic H1N1 virus impacted maternal mortality almost exclusively from the respiratory system- and sepsis-related complications.

Funding

Supported by FISAR www.fisarchile.org.

Acceptance of seasonal influenza vaccination and associated factors among pregnant women in the context of COVID-19 pandemic in China: a multi-center cross-sectional study based on health belief model

Background

Seasonal influenza can circulate in parallel with coronavirus disease (COVID-19) in winter. In the context of COVID-19 pandemic, the risk of co-infection and the burden it poses on healthcare system calls for timely influenza vaccination among pregnant women, who are the priority population recommended for vaccination. We aimed to evaluate the acceptance of influenza vaccination and associated factors among pregnant women during COVID-19 pandemic, provide evidence to improve influenza vaccination among pregnant women, help reduce the risk of infection and alleviate the burden of healthcare system for co-infected patients.

Methods

We conducted a multi-center cross-sectional study among pregnant women in China. Sociodemographic characteristics, health status, knowledge on influenza, attitude towards vaccination, and health beliefs were collected. Locally weighted scatterplot smoothing regression analysis was used to evaluate the trends in the acceptance of influenza vaccine. Logistic regression was applied to identify factors associated with vaccination acceptance.

Results

The total acceptance rate was 76.5% (95%CI: 74.8–78.1%) among 2568 pregnant women enrolled. Only 8.3% of the participants had a history of seasonal influenza vaccination. In the logistic regression model, factors associated with the acceptance of influenza vaccine were western region, history of influenza vaccination, high knowledge of influenza infection and vaccination, high level of perceived susceptibility, perceived benefit, cues to action and low level of perceived barriers. Among 23.5% of the participants who had vaccine hesitancy, 48.0% of them were worried about side effect, 35.6% of them lacked confidence of vaccine safety.

Conclusions

Our findings highlighted that tailored strategies and publicity for influenza vaccination in the context of COVID-19 pandemic are warranted to reduce pregnant women’s concerns, improve their knowledge, expand vaccine uptake and alleviate pressure for healthcare system.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-04224-3.

COVID-19 mRNA vaccines drive differential antibody Fc-functional profiles in pregnant, lactating, and nonpregnant women

Substantial immunological changes occur throughout pregnancy to promote tolerization of the mother to the fetus and allow fetal growth. However, additional local and systemic immunological adaptations also occur, allowing the maternal immune system to continue to protect the dyad against pathogens both during pregnancy and after birth through lactation. This fine balance of tolerance and immunity, along with physiological and hormonal changes, contribute to increased susceptibility to particular infections in pregnancy, including more severe coronavirus disease 2019 (COVID-19). Whether these changes also make pregnant women less responsive to vaccination or induce altered immune responses to vaccination remains incompletely understood. To holistically define potential changes in vaccine response during pregnancy and lactation, we deeply profiled the humoral vaccine response in a group of pregnant and lactating women and non-pregnant age-matched controls. Vaccine-specific titers were comparable between pregnant women, lactating women, and non-pregnant controls. However, Fc receptor (FcR)-binding and antibody effector functions were induced with delayed kinetics in both pregnant and lactating women compared to non-pregnant women after the first vaccine dose, which normalized after the second dose. Antibody boosting resulted in high FcR-binding titers in breastmilk. These data suggest that pregnancy promotes resistance to generating highly inflammatory antibodies and indicates that there is a critical need to follow prime-boost timelines in this vulnerable population to ensure full immunity is attained.

Pregnant and lactating women develop distinct antibody Fc profiles in response to the mRNA-1273 and BNT162b2 vaccines compared to non-pregnant women.

What do pregnant women think about influenza disease and vaccination practices in selected countries

Introduction: We evaluated knowledge, attitudes, and practices (KAP) related to influenza and influenza vaccination among pregnant women in three selected countries.Methods: During 2017, pregnant women seeking antenatal care at hospitals at participating sites were enrolled. We described characteristics and responses to KAP questions. We also evaluated predictors associated with influenza vaccination during pregnancy at sites with substantial influenza vaccine uptake by multivariable logistic regression.Results: Overall, 4,648 pregnant women completed the survey. There were substantial differences among the three survey populations; only 8% of the women in Nagpur had heard of influenza, compared to 90% in Lima and 96% in Bangkok (p-value<0.01). Despite significant differences in sociodemographic characteristics in the three populations, most participants across sites who were aware of influenza prior to study enrollment believe they and their infants are at risk of influenza and related complications and believe influenza vaccination is safe and effective. Half of women in Lima had verified receipt of influenza vaccine compared to <5% in Bangkok and Nagpur (p < .05). For further analysis conducted among women in Lima only, household income above the poverty line (aOR: 1.38; 95%CI: 1.01, 1.88), having 8+ antenatal visits, compared to 0-4 (aOR: 2.41; 95%CI: 1.39, 2.87, respectively), having 0 children, compared to 2+ (aOR: 1.96; 95%CIs: 1.23, 3.12), and vaccination recommended by a health-care provider (aOR: 8.25; 95%CI: 6.11, 11.14) were strongly associated with receipt of influenza vaccine during pregnancy.Conclusions: Our findings identify opportunities for targeted interventions to improve influenza vaccine uptake among pregnant women in these settings.

Maternal death related to COVID-19: A systematic review and meta-analysis focused on maternal co-morbidities and clinical characteristics

Background

Besides reducing the quality of obstetric care, the direct impact of COVID‐19 on pregnancy and postpartum is uncertain.

Objective

To evaluate the characteristics of pregnant women who died due to COVID‐19.

Search strategy

Cochrane Library, Embase, MEDLINE, Scopus, and Google Scholar were searched from inception to February 2021.

Selection criteria

Studies that compared deceased and survived pregnant women with COVID‐19.

Data collection and analysis

Relevant data were extracted and tabulated. The primary outcome was maternal co‐morbidity.

Main results

Thirteen studies with 154 deceased patients were included. Obesity doubled the risk of death (relative risk [RR] 2.48, 95% confidence interval [CI] 1.41–4.36, I² = 0%). No differences were found for gestational diabetes (RR 5.71; 95% CI 0.77–42.44, I² = 94%) or asthma (RR 2.05, 95% CI 0.81–5.15, I² = 0%). Overall, at least one severe co‐morbidity showed a twofold increased risk of death (RR 2.26, 95% CI 1.77–2.89, I² = 76%). Admission to intensive care was related to a fivefold increased risk of death (RR 5.09, 95% CI 2.00–12.98, I² = 56%), with no difference in need for respiratory support (RR 0.53, 95% CI 0.23–1.48, I² = 95%) or mechanical ventilation (RR 4.34, 95% CI 0.96–19.60, I² = 58%).

Conclusion

COVID‐19 with at least one co‐morbidity increases risk of intensive care and mortality.

Pregnant women with COVID‐19 infection and at least one severe co‐morbidity experience increased risk of death and admission to the intensive care unit.

COVID-19 mRNA vaccines drive differential Fc-functional profiles in pregnant, lactating, and non-pregnant women

Significant immunological changes occur throughout pregnancy to tolerize the mother and allow growth of the fetal graft. However, additional local and systemic immunological adaptations also occur, allowing the maternal immune system to continue to protect the dyad against foreign invaders both during pregnancy and after birth through lactation. This fine balance of tolerance and immunity, along with physiological and hormonal changes, contribute to increased susceptibility to particular infections in pregnancy, including more severe COVID-19 disease. Whether these changes also make pregnant women less responsive to vaccination or induce altered immune responses to vaccination remains incompletely understood. To holistically define potential changes in vaccine response during pregnancy and lactation, we deeply profiled the humoral vaccine response in a group of pregnant and lactating women and non-pregnant age-matched controls. Vaccine-specific titers were comparable, albeit slightly lower, between pregnant and lactating women, compared to non-pregnant controls. Among pregnant women, we found higher antibody titers and functions in those vaccinated with the Moderna vaccine. FcR-binding and antibody effector functions were induced with delayed kinetics in both pregnant and lactating women compared to non-pregnant women. Antibody boosting resulted in high FcR-binding titers in breastmilk. These data point to an immune resistance to generate highly inflammatory antibodies during pregnancy and lactation, and a critical need to follow prime/boost timelines in this vulnerable population to ensure full immunity is attained.

Clinical Effectiveness and Safety of Antivirals for Influenza in Pregnancy

Seasonal influenza epidemics result in substantial health care burden annually. Early initiation of antiviral treatment of influenza has been shown to reduce the risk of complications and duration of illness. Pregnant and postpartum women may be at increased risk for influenza-associated complications; however, pregnant women have been generally excluded from clinical trials of antiviral treatment of influenza. In this review, we summarize the available evidence on the clinical effectiveness and safety of antiviral treatment of pregnant women with influenza. Observational data show a reduction of severe outcomes when pregnant and postpartum women are treated with oseltamivir and other neuraminidase inhibitors without increased risk of adverse maternal, fetal, or neonatal outcomes. Due to lack of safety and efficacy data for baloxavir treatment of pregnant and postpartum women, baloxavir is currently not recommended for use in these populations.

Coronavirus disease 2019 (COVID-19) manifestations during pregnancy in all three trimesters: A case series

Background

Coronavirus disease 2019 (COVID-19) pandemic has raised concerns about the susceptibility amongst different groups of the population. Pregnant women are one such group. This study was conducted to investigate the effect of COVID-19 on pregnancy and maternal/neonatal outcomes.

Case presentation

This case series was conducted on 16 pregnant women with COVID-19 from March 21 to May 11, 2020. Clinical characteristics, pregnancy complications, medication used, maternal/neonatal outcomes, and fatality rate were investigated through this study. The mean age of the patients was 30.06 yrs. Patients from all three trimesters were included (1 in first, 5 in second, and 10 in the third trimesters). The most common clinical symptoms were shortness of breath (n = 10), dry cough (n = 10), myalgia (n = 8), and chills (n = 7). Also, three cases had papulosquamous skin lesions with fissuring. The most common laboratory results were leukocytosis (n = 8), increased liver enzymes (n = 6), elevated CRP (n = 5), and thrombocytopenia (n = 4). There was one case of maternal mortality, five of premature labor pain (PLP), two of preeclampsia, and two of placenta accreta. Twelve pregnancies were terminated (nine cesarean sections, three vaginal deliveries). Among neonates, we had 6 cases of preterm labor. All neonates had negative PCR results.

Conclusion

Clinical manifestations and paraclinical results were similar to non-pregnant patients. There was no evidence of vertical transmission. PLP and premature rupture of membranes (PROM) were the most common complications in the second and third trimesters of pregnant COVID-19 women, which can lead to rupture of the uterus. Termination and delivery should be planned individually.

Knowledge, attitudes and practices on influenza vaccination during pregnancy in Quito, Ecuador

Background

Vaccination is the most effective way to prevent infection and severe outcomes caused by influenza viruses in pregnant women and their children. In Ecuador, the coverage of seasonal influenza vaccination in pregnant women is low. The aim of this study was to assess the knowledge, attitudes, and practices (KAP) of pregnant women toward influenza vaccination in Quito-Ecuador.

Methods

A cross-sectional study enrolled 842 women who delivered at three main public gynecological-obstetric units of the Metropolitan District of Quito. A questionnaire regarding demographics, antenatal care, risk conditions and knowledge, attitudes and practices related to influenza vaccination was administered. We examined factors associated with vaccination using log-binomial regression models.

Results

A low vaccination rate (36.6%) against influenza was observed among pregnant women. The factors associated with vaccination included the recommendations from health providers (adjusted PR: 15.84; CI 95% 9.62–26.10), belief in the safety of the influenza vaccine (adjusted PR: 1.53; CI 95% 1.03–2.37) and antenatal care (adjusted PR: 1.21; CI 95% 1.01–1.47). The most common reasons for not vaccinating included the lack of recommendation from health care providers (73.9%) and lack of access to vaccine (9.0%).

Conclusions

Health educational programs aimed at pregnant women and antenatal care providers have the most potential to increase influenza vaccination rates. Further studies are needed to understand the barriers of health care providers regarding influenza vaccination in Ecuador.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-020-10061-4.

Clinical features of pregnant women in Iran who died due to COVID-19

Background

To evaluate the clinical presentation of pregnant women in Iran who died due to COVID‐19.

Methods

Data were evaluated of pregnant women who died following a laboratory diagnosis of COVID‐19. The data were obtained from electronic medical records. Additionally, a questionnaire was completed for each patient, including demographic, clinical, laboratorial, imaging, and treatment data. In case of missing information, a member of the research team contacted the first‐degree relatives via phone.

Results

Of 32 pregnant women who tested positive for COVID‐19, 15 were enrolled into the study (mean age 30.0 ± 5.0 years). The mean time from first symptoms to death was 12 ± 7.0 days. Pre‐existing comorbidities were seen in six patients. The main presentations at admission were fatigue and coughing, but most of the women had a fever below 38 °C. Increased white blood cell count and neutrophils were noticeable. A significant drop of saturation of O₂ with ground glass and consolidation seen in both lungs were prominent. The most common complications were acute respiratory distress syndrome followed by respiratory failure.

Conclusion

Computed tomography findings, O₂ pressure, and regular blood assessment may be considered suitable indicators for the surveillance of patients.

O₂ pressure, computed tomography findings, and complete blood count differential at admission are important items for predicting the outcome and surveillance of pregnant women.

Clinical characteristics and risk factors for mortality in obstetric patients with severe COVID-19 in Brazil: a surveillance database analysis

Objective

To describe clinical characteristics of pregnant and postpartum women with severe COVID‐19 in Brazil and to examine risk factors for mortality.

Design

Cross‐sectional study based on secondary surveillance database analysis.

Setting

Nationwide Brazil.

Population or sample

978 Brazilian pregnant and postpartum women notified as COVID‐19 Acute Respiratory Distress Syndrome (ARDS) cases with complete outcome (death or cure) up to 18 June 2020.

Methods

Data was abstracted from the Brazilian ARDS Surveillance System (ARDS‐SS) database. All eligible cases were included. Data on demographics, clinical characteristics, intensive care resources use and outcomes were collected. Risk factors for mortality were examined by multivariate logistic regression.

Main outcome measures

Case fatality rate.

Results

We identified 124 maternal deaths, corresponding to a case fatality rate among COVID‐19 ARDS cases in the obstetric population of 12.7%. At least one comorbidity was present in 48.4% of fatal cases compared with 24.9% in survival cases. Among women who died, 58.9% were admitted to ICU, 53.2% had invasive ventilation and 29.0% had no respiratory support. The multivariate logistic regression showed that the main risk factors for maternal death by COVID‐19 were being postpartum at onset of ARDS, obesity, diabetes and cardiovascular disease, whereas white ethnicity had a protective effect.

Conclusions

Negative outcomes of COVID‐19 in this population are affected by clinical characteristics but social determinants of health also seem to play a role. It is urgent to reinforce containment measures targeting the obstetric population and ensure high quality care throughout pregnancy and the postpartum period.

Tweetable abstract

A total of 124 COVID‐19 maternal deaths were identified in Brazil. Symptoms onset at postpartum and comorbidities are risk factors.

A total of 124 COVID‐19 maternal deaths were identified in Brazil. Symptoms onset at postpartum and comorbidities are risk factors.

Maternal mortality and COVID-19

OBJECTIVE

The aim of this study was to collect and analyze data from different sources to have a general overview of COVID-19-related maternal deaths in Brazil, as well as to compare data with worldwide reports.

STUDY DESIGN

We systematically searched data about COVID-19 maternal deaths from the Brazilian Ministry of Health surveillance system, State Departments of Health epidemiological reports, and media coverage. Data about timing of symptom onset and death (pregnancy or postpartum), gestational age, mode of birth, maternal age, comorbidities and/or risk factors, date of death, and place of death were retrieved when available.

RESULTS

We identified 20 COVID-19-related maternal deaths, age range 20-43 years. Symptoms onset was reported as on pregnancy for 12 cases, postpartum for 3 cases, and during the cesarean section for 1 case (missing data for 4). In 16 cases, death occurred in the postpartum period. At least one comorbidity or risk factor was present in 11 cases (missing data for 4). Asthma was the most common risk factor (5/11). Ten cases occurred in the Northeast region, and nine cases occurred in the Southeast region (5 of them in São Paulo, the first epicenter of COVID-19 in the country).

CONCLUSIONS

To the best of our knowledge, this is the largest available series of maternal deaths due to COVID-19. Barriers to access healthcare, differences in pandemic containment measures in the country and high prevalence of concomitant risk factors for COVID-19 severe disease may play a role in the observed disparity compared to worldwide reports on maternal outcomes.

The faces of influenza vaccine recommendation: A Literature review of the determinants and barriers to health providers' recommendation of influenza vaccine in pregnancy

INTRODUCTION

WHO recommends influenza vaccination for pregnant women and health providers (HPs), yet global uptake for both is persistently low. Research suggests that HPs greatly influence uptake of influenza vaccine in pregnant women. Our review studies HPs' recommendation of influenza vaccine to pregnant women, determinants and barriers to recommendation, and the role that HPs may play in global influenza vaccine coverage.

METHODS

We undertook a comprehensive global review of literature relating to HPs' recommendation of seasonal influenza vaccines to pregnant women and the determinants and barriers to recommendation and how this may vary by country and context. We evaluated data from each study including frequency of HP recommendation, vaccine coverage, determinants and barriers to recommendation, and the odds of recommending. We tracked the frequency of determinants and barriers to recommendation in heat maps and organized data by world regions and income classifications.

RESULTS

From 32 studies in 15 countries, we identified 68 determinants or barriers to HPs' recommendation. Recommendation rates were highest (77%) in the Americas and lowest in South East Asia (18%). A HP's own influenza vaccine status was a main determinant of recommendation in multiple country contexts and from different provider types. Financial barriers to recommendation were present in higher-income countries and policy-related barriers were highlighted in lower-income countries. HP perceptions of safety, efficacy, and the utility of vaccine were the most frequently cited barriers, relevant in almost every context.

CONCLUSIONS

HP recommendation is important to influenza vaccine implementation in pregnant women. A HP's own status is an important recommendation determinant in multiple contexts. Vaccine program implementation plans should consider the impact of HPs' knowledge, awareness and vaccine confidence on their own uptake and recommendation practices, as well as on the uptake among pregnant women. Addressing safety and efficacy concerns is relevant in all contexts for HPs and pregnant women.

Vaccinations during pregnancy: a call to sting into action

Safety and efficacy of vaccinations during pregnancy have been a matter of debate. In the aftermath of the 2009 H1N1 influenza pandemic, a growing body of research has emerged, which points toward the importance of adhering to influenza vaccination recommendations for pregnant women. The same applies for vaccination against pertussis. Some vaccines (e.g., live attenuated) are still contraindicated during pregnancy. However, data indicate that these vaccines do not result in fetal impairment when administered accidentally during pregnancy. In the following, we provide a review on vaccination-related safety and efficacy aspects in pregnant women, shedding some light on potential barriers that stymie vaccination uptake among pregnant women and introducing strategies to overcome these barriers.

Prenatal influenza vaccination rescues impairments of social behavior and lamination in a mouse model of autism

Background

Prenatal infection is a substantial risk factor for neurodevelopmental disorders such as autism in offspring. We have previously reported that influenza vaccination (VAC) during early pregnancy contributes to neurogenesis and behavioral function in offspring.

Results

Here, we probe the efficacy of VAC pretreatment on autism-like behaviors in a lipopolysaccharide (LPS)-induced maternal immune activation (MIA) mouse model. We show that VAC improves abnormal fetal brain cytoarchitecture and lamination, an effect associated with promotion of intermediate progenitor cell differentiation in MIA fetal brain. These beneficial effects are sufficient to prevent social deficits in adult MIA offspring. Furthermore, whole-genome analysis suggests a strong interaction between Ikzf1 (IKAROS family zinc-finger 1) and neuronal differentiation. Intriguingly, VAC rescues excessive microglial Ikzf1 expression and attenuates microglial inflammatory responses in the MIA fetal brain.

Conclusions

Our study implies that a preprocessed influenza vaccination prevents maternal bacterial infection from causing neocortical lamination impairments and autism-related behaviors in offspring.

Electronic supplementary material

The online version of this article (10.1186/s12974-018-1252-z) contains supplementary material, which is available to authorized users.

Factors associated with uptake of influenza and pertussis vaccines among pregnant women in South Australia

BACKGROUND

Maternal immunization is an effective strategy to protect pregnant women and their infants from vaccine-preventable diseases. Despite the recommendation of maternal influenza and more recently pertussis immunization in Australia, uptake of these vaccines has been suboptimal. A midwife delivered immunization program for pregnant women at the Women's and Children's Hospital in South Australia commenced in April 2015. Monitoring the uptake of the current funded vaccine programs for pregnant women is limited. The study aimed to estimate maternal vaccine uptake and assess factors associated with influenza and pertussis vaccine uptake among pregnant women.

METHODS

This prospective study was undertaken between November 2014 and July 2016 at the Women's and Children's Hospital. Following consent, demographic details and vaccination history for South Australian pregnant women who attended the antenatal clinic were collected. A standardised self-reported survey was completed during pregnancy with a follow up telephone interview at 8-10 weeks post-delivery.

RESULTS

205 women consented and completed the self-reported survey. Of the 180 pregnant women who completed the study, 76% and 81% received maternal influenza and pertussis vaccines respectively. The adjusted odds of women receiving maternal vaccines during pregnancy were significantly higher for women delivering after the implementation of the midwife delivered program compared with women who delivered babies prior to the program for both pertussis vaccination (AOR 21.17, 95% CI 6.14-72.95; p<0.001) and influenza vaccination (AOR 5.95, 95% CI 2.13-16.61, p<0.001). Women receiving a recommendation from a health care provider and first time mothers were significantly more likely to receive influenza vaccination during pregnancy.

CONCLUSIONS

High uptake of influenza and pertussis vaccines during pregnancy can be attained with health care provider recommendation and inclusion of maternal immunization as part of standard antenatal care. A midwife delivered maternal immunization program is a promising approach to improve maternal vaccine uptake by pregnant women.