key: cord-0749228-u5fg08k1
authors: Twanow, Jaime-Dawn E.; McCabe, Corinne; Ream, Margie
title: The COVID-19 Pandemic and Pregnancy: Impact on Mothers and Newborns
date: 2022-05-21
journal: Semin Pediatr Neurol
DOI: 10.1016/j.spen.2022.100977
sha: aeb2c5b6d73b3e5e0d47fd659ee0e38a3f6e2863
doc_id: 749228
cord_uid: u5fg08k1

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-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 COVID-19 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 COVID-19 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.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the worldwide pandemic of symptomatic COVID-19 infection 1 has disrupted our medical, social, and economic spheres in a fashion unprecedented in modern times. The pandemic of symptomatic infection, referred to as COVID-19, has disrupted our medical, social, and economic spheres in a fashion unprecedented in modern times. The initial lack of evidence has been followed by a seemingly endless onslaught of rapidly changing recommendations. This has significantly complicated patient care, including obstetric and perinatal care of mothers and infants, regardless of SARS-CoV-2 infection status. With the acknowledgment that the field is still evolving, the recent available evidence guiding the care of pregnant women and infants impacted or infected by the pandemic is summarized in this focused, point in time review.

A women's personal health and her pregnancy are placed at risk by COVID-19. Pregnant women with symptomatic COVID-19 infection, when compared to non-pregnant women with COVID-19, (and adjusted for race, age, ethnicity, and underlying medical conditions) are 3 times more likely to be admitted to an intensive care unit (10.5 vs 3.9 per 1000 cases), 2.9 times more likely to require invasive ventilation (2.9 vs 1.1 per 1000 cases), 2.4 times more likely to require extra-corporeal membrane oxygenation (0.7 vs 0.3 per 1000 cases), and 1.7 times more likely to die (1.5 vs 1.2 per 1000 cases). 2 Ko et al., found that in pregnant women with a COVID-19 diagnosis, there was an increased risk of acute respiratory distress syndrome (adjusted relative risk [aRR] 34.4), sepsis (aRR = 13.6), need for mechanical ventilation (aRR = 12.7) and death (aRR = 17) compared to pregnant women without COVID-19 infection. Additionally, increased risk for acute renal failure, adverse cardiac events, and thromboembolic events was recognized in the infected group. 3 The increased risk of severe disease during pregnancy is likely secondary to physiologic adaptations in the respiratory, cardiovascular, and immunologic systems. These changes include decreased lung residual volume due to elevation of the diaphragm and potential pulmonary hypertension, which can lead to hyperventilation. Increased maternal metabolic demand, gestational anemia, and fetal oxygen consumption make respiratory compromise and hypoxic respiratory failure more likely. 5 Viral illness can raise metabolic demand and increase pulmonary vascular resistance, further stressing an already taxed system of oxygen delivery. 5 Other factors that independently increase severity of disease are similar to non-pregnant patients, including increased age, higher body mass index, and pre-existing comorbidities including hypertension, chronic lung disease (i.e. asthma or chronic obstructive pulmonary disease), and pre-gestational diabetes. 2

Transplacental infection of the fetus, also referred to as vertical transmission, can be diagnosed when viral antigen or RNA is identified in fetal-derived placental cells. 6 This finding is rare but has been demonstrated with evidence of virus in villous syncytiotrophoblast, endothelial cells, fibroblasts, and, most notably, fetal intravascular monocytes. 7 SARS-CoV-2 infects individuals by binding the spike protein on angiotensin-2 converting enzymes (ACE2) receptors and using the proteolytic host serine protease, transmembrane protease serine 2 (TMPRSS2), for entry into the cell. 8 Multiple cell types in the placenta, including placental syncytiotrophoblast and cytotrophoblast, express these proteins starting at 7 weeks gestation, allowing for SARS-CoV-2 placental infection. These receptors are not highly expressed in fetal lung tissue, and are not present in fetal brain tissue. 9, 10 Despite the presence of the cellular machinery to facilitate placental and transplacental infection, such infection is rare. In a series of 1457 pregnant women with infection in any trimester, SARS-CoV-2 RNA was detected in placental tissue of 13 (0.89%) pregnancies. 11 In another study, placental syncytiotrophoblasts were infected in 12% of pregnant women with COVID-19. 10 Both of these numbers are quite low when compared to other viruses, for instance, CMV infects 35% of fetuses if primary maternal infection occurs during pregnancy. 12 Mechanisms that protect from invasion of fetal tissue by SARS-CoV-2 are yet to be elucidated.

The authors of articles detailing first trimester infections have largely reported uncomplicated deliveries and favorable short term neonatal outcomes. [13] [14] [15] The authors of a study of over 3,000 pregnant women including 1,456 women with SARS-CoV-2 infection in the first trimester found no statistical differences between groups in intrauterine fetal distress, fetal growth restriction, premature delivery or low birth weight. 15 The authors of case reports illustrate the spectrum of potential fetal outcomes. In one case report, the authors described a mild maternal infection and the uneventful delivery of an asymptomatic, but RT-PCR positive neonate with viral particles detected in placental villous syncytiotrophoblast. 16 In contrast, an asymptomatic maternal infection at 8 weeks was followed by fetal hydrops at 10 weeks and fetal demise at 13 weeks, in the context of persistent maternal RT-PCR positivity. 14 Placenta, amniotic fluid and fetal tissues were all positive for virus The authors of another study described a pregnancy complicated by symptomatic maternal SARS-CoV-2 infection mid first trimester, producing a single neonate born with congenital microphthalmia and optic nerve hypoplasia. Extensive genetic testing, teratogenic exposure history, and investigation for other infectious etiologies was unrevealing, therefore this may demonstrate a potential rare complication of SARS-CoV-2 infection. 14 This range of outcomes illustrates the broad clinical scope of this illness, and highlights the challenges involved in accurately identifying high risk pregnancies.

With a heightened awareness of the potential for complications, the American College of Obstetricians and Gynecologists (ACOG) currently recommends that women with first trimester infection undergo a detailed mid-trimester anatomy ultrasound. For infections in the second or third trimesters, additional third-trimester growth ultrasounds could be considered based on severity of illness and maternal course. 8, 17 Going forward, long term follow up is needed to determine the impact of maternal infection on infant development and cognition.

A SARS-CoV-2 infection during pregnancy can result in variable placental histologic findings ranging from normal to severely abnormal, with intervillositis, accelerated villous maturation, chorioamnionitis, thrombosis, and placental infarction reported. 7 The severity of maternal illness does not necessarily correlate with the severity of pathologic findings in the placenta, and maternal infection can cause an inflammatory response in the placenta without detectable virus in placental tissue. 18, 19 There is also increased oxidative damage, decreased mitochondrial function, and altered gene expression in placentas of pregnancies complicated by COVID-19. 20, 21 There may be an evolution of pathologic and histologic findings in term-delivered placentas based on the time since infection, but few cases have been directly compared. 22 In a group of 6 live born neonates with SARS-CoV-2 and 5 fetuses experiencing intrauterine demise, all placentas showed chronic histiocytic intervillositis and trophoblast necrosis. 23 In contrast, the authors of a series of 50 placentas from third trimester COVD-19 infection, reported that pathologic findings did not differ from 50 historical controls prior to the pandemic. 24 Chronic histiocytic intervillositis, which can be associated with maternal placental malperfusion, has been described, even in cases with negative placental and fetal/neonatal tissue testing and mild maternal illness. 25 These abnormalities in placental pathology are generally associated with negative neonatal neurodevelopmental outcomes regardless of causative factors, 26 therefore infants born after pregnancies complicated by SARS-CoV-2 infection warrant longitudinal follow up to monitor outcomes.

Criteria defining early onset neonatal SARS-CoV-2 infection, including RT-PCR positivity in the first 72 hours of life, have been proposed. 6 An estimated 30% of all neonates who become infected with SARS-CoV-2 are infected either through intrauterine or intrapartum mechanisms, while the 70% majority of neonates are infected through direct contact with aerosolized respiratory secretions or via droplet transmission of the virus. 27 

Risks to the fetus/newborn likely relate to the timing and severity of maternal infection. Most reports focus on third trimester infection, when a woman is at greatest risk of severe disease. Although only 3% of infants born to infected mothers test positive for SARS-CoV-2 18 32 were also more common in mothers with laboratory confirmed SARS-CoV-2 infection. 33 Although outcomes vary, the recognized risk of complications indicates that the infant-mother dyad with third trimester infection warrants close observation.

Initially, SARS-CoV-2 infection in children under 18 accounted for 1-2% of cases, although this was potentially an underestimate due to generally mild or asymptomatic infection in children, and less testing capacity in the early stages of the pandemic. Pediatric infections now represent 25% of all new SARS-CoV-2 infections. 34 Overall short-term outcomes are good with 90% of children less than five years old developing mild to moderate degree of illness. Infants ( >7 days and <1 year) with COVID-19 typically experience only rare intubations, have brief hospital stays, and boast more than 99% survival. 35, 36 Work is ongoing to define risk factors for severe disease and determine potential outcomes for these patients, as certain infants may be at higher risk of severe infection than older children. The authors of a study in the United Kingdom demonstrated 2 periods of increased risk for ICU admission for children; under 1 month of age (OR = 3.21, 1.36-7.66; p = 0.008) and between ages 10-14 years (3.23, 1.55-6.99; p = 0.002). 37 Severe disease in neonates and infants can occur, and neonatal multisystem inflammatory syndrome (N-MISC) with associated organ dysfunction has been reported. Neonates at greatest risk for severe disease are those with underlying or pre-existing medical conditions, such as cyanotic heart disease, immunodeficiency, extreme prematurity, N-MISC, or co-infection. 35, 38, 39 Long-Term Outcomes Short-term outcomes have overall been reassuring for neonates, however there is a pressing need to characterize the long-term effects of SAR-CoV-2 infection. Although vertical transmission during pregnancy or delivery from mother to the fetus/neonate is low, the consequences of in-utero exposure are unknown. Researchers are presently evaluating neurodevelopmental and multidisciplinary outcomes following in-utero exposure to maternal infection. 40, 41 One comprehensive study assessed infants at 3month intervals, following growth, weight gain, head circumference, neurologic development, IgG antibody levels, and documenting hearing function (as SARS-CoV-2 can cause sensorineural hearing loss) and ophthalmology examinations. More than 90% of mothers of this cohort contracted the infection in the third trimester, with 2% of neonates testing positive in the first 24 hours, although all were asymptomatic. All children enrolled had normal growth parameters, independent of timing or severity of maternal infection. Of the 20 children who received an ophthalmologic exam, 3 (15%) had retinal abnormalities but maintained normal fixation, tracking and saccadic movements. 40 The authors of an ongoing developmental study are comparing infants from infected and non-infected pregnancies to historical healthy controls assessed prior to the pandemic. 41 Preliminary data shows no significant associations between maternal SARS-CoV-2 infection (status, timing or severity) and infant neurodevelopment. No significant differences were identified in communication, gross motor, fine motor, problem solving or personal-social domains when comparing exposed to non-exposed infants.

However, growing up in the pandemic seems to be taking a toll. Although these preliminary studies are being conducted at single centers in areas heavily impacted by COVID-19, they show that although exposure to the infection itself may not alter neurodevelopmental outcomes, the societal changes associated with the pandemic may have underappreciated effects.

More developmental time and assessments on children born during the pandemic, ideally in multiple regions, are needed.

At the onset of the pandemic, the worldwide emergency state required rapid policy creation to guide the management of pregnancy and delivery. As the risk of perinatal and postnatal transmission of SARS-CoV-2 was not known, strict initial regulations were enacted. In the case of SARS-CoV-2-positive mothers, early recommendations stipulated that woman were to be isolated from their infants and breast feeding or use of expressed breast milk was not recommended due to safety concerns. 43 Concerns were immediately raised regarding the long-term consequences of these strategies, including interference with mother-child bonding and breast-feeding establishment. 8 ,44 In many systems, early in the pandemic, partners were excluded from the delivery suite and visitation was severely restricted, even limiting or prohibiting visitation of neonates in the NICU. These changes prevented skin to skin and kangaroo/maternal care (KMC), disrupting the family centered care models that are widely accepted, models that have been proven to reduce morbidity and mortality in low birthweight infants. 38, 45 The authors of outcomes research have confirmed increased parental emotional and psychological stress, and speculate increased long-term risks for parental post-traumatic stress disorder and postpartum depression stemming from these early policies. 38, 46 

Over the course of the progression of the pandemic, pre-and perinatal care policies have shifted. 

The low rate of horizontal transmission of SARS-CoV-2 has largely extinguished policies separating mother-infant dyads, even when the mother is SARS-CoV-2-positive. The estimated post-natal transmission rate of approximately 2% for infants rooming and nursing with an infected mother has allowed for "protected rooming in" (with contact and droplet precautions) to become the accepted practice. 38, 48, 49 This revision of regulations extends even to the most vulnerable infants. Evidence supports that the survival benefit of KMC in the NICU far outweighs the risk of death due to SARS-CoV-2 infection in premature infants with birth weight < 2000 g admitted to the neonatal care unit (NICU).

Modelled scenarios estimate infant lives saved by continuing KMC during the pandemic will be 65 to 630-fold higher than the mortality risk from transmitted SARS-CoV-2 in the NICU population. 50

The safety of direct breastfeeding and using expressed milk from a SARS-CoV-2-positive mother was an initial area of concern. Subsequent work following surveillance testing of serial nasopharyngeal swabs of breastfed infants who roomed in with infected mothers confirmed low rates of infection in the 4 weeks following delivery when safety protocols (maternal masking and hand washing prior to infant cares) were followed. 38 51 There has been a reassuring lack of clinically identified infections spread by breast milk, 38 and no replication-competent or transmissible SARS-CoV-2 viral particles have been found in reliably performed breast milk testing. 48 Finally, although in vivo immunologic impact is not well characterized, testing confirms that breast milk contains IgA, IgG and IgM antibodies capable of neutralizing SARS-CoV-2 viral infectivity in vitro 38, 52 . This evidence has shifted the field to support direct breast feeding and feeding with expressed breast milk (with safety practices) for infected mothers providing infant care in the hospital and at home. Several health organizations have published clinical guidelines, with both unique and shared features, outlining the framework for safely caring for infants born to SARS-CoV-2-positive mothers. (Table 1 ) 

The increased understanding of risks of maternal infection during pregnancy and the associated risks to 

Although the intention was not to deliberately study vaccines during pregnancy, several pregnancies occurred after women were enrolled and vaccinated in initial trials. There were not notable differences in adverse events or side effects when the vaccinated pregnant group was compared to the nonpregnant group. In the interval since the initial trials, more than 30,000 vaccinated pregnant women have been reported to the V-safe vaccine safety monitoring program, including 275 completed pregnancies and 232 live births. 58 Data reviewed in February 2021 showed pregnancy outcomes and adverse events of vaccinated women have been consistent with baseline pregnancy rates, and "no unexpected pregnancy or infant outcomes have been observed related to COVID-19 vaccination during pregnancy". 62 (Figure 1 ) COVID-19 safety in pregnancy is postulated to be related to their unique mechanisms of action. mRNA vaccines have a short half-life of 8-10 hours and are unable to enter the cell nucleus, therefore cannot be transmitted to a developing fetus. 60 

The unique vaccine features postulated to allow safe administration during pregnancy, are also believed to make mRNA and Janssen vaccines safe during lactation. Injected mRNA material and the transcribed protein is briefly present in the mother's body after injection. Although vaccine material is not expected to enter the breast milk, any particles would be broken down into a nonfunctional product during milk digestion. As there is not a viremic state following Janssen vaccine administration, there is no opportunity for entry of the adenovirus vector into the milk supply. 58 Breast milk tested from mothers vaccinated during or after pregnancy contains IgA and IgG antibodies. Peak levels of the immunoglobulin occur between 4 and 6 weeks after the first vaccine dose. 64, 65 

Available follow up of mother-infant dyads vaccinated during pregnancy demonstrates encouraging and interesting vaccine efficacy data. Vaccinated pregnant and lactating mothers have side effect profiles and antibody response similar to non-pregnant/nursing vaccinated women. They also have higher antibody levels than women who acquire natural infection during pregnancy. 64, 66 Cord blood samples from mothers vaccinated during pregnancy have measurable level of binding and neutralizing antibodies, indicative of the potential for transmission of passive immunity to the infant. 65 Review of hospital admissions in infants less than 6 months of age by Halasa et al., found that maternal vaccination with 2 doses of an mRNA vaccine was associated with a decreased risk of COVID-19 related hospitalization for infants. Overall, vaccination during pregnancy was 61% effective (95% CI 31-78%) in preventing COVID-related hospital admissions for infants. Stratifying the data, vaccination in the first 20 weeks of pregnancy was 32% effective (95% CI 43-68%), while vaccination after 21 weeks of pregnancy up to 2 weeks prior to delivery was 80% effective in preventing infant hospitalization for COVID-19 (95% CI 55% to 91%). This work suggests that completion of maternal vaccination series during pregnancy may offer protection against hospitalization for COVID-19 in infants less than 6 months of age, although the ideal timing of vaccination remains unknown. 67

Two years into the pandemic, prenatal care, perinatal care, and post-natal care of women and infants has been significantly altered, with unknown long-term ramifications. The impact of the SARS-CoV-2 virus extends beyond the physical effects of the COVID-19 infection itself. Early evidence indicates that the social and emotional changes associated with the pandemic have meaningfully impacted the health of both women and infants. Although there is a growing base of reliable evidence to guide the comprehensive care of pregnant women and their infants in the context of SARS-CoV-2, high quality

Vertical Transmission and Neonatal Outcomes Following Maternal SARS-CoV-2 Infection During Pregnancy

An update on COVID-19 and pregnancy

Adverse Pregnancy Outcomes, Maternal Complications, and Severe Illness Among US Delivery Hospitalizations With and Without a Coronavirus Disease 2019 (COVID-19) Diagnosis

Papageorghiou AT. Maternal and Neonatal Morbidity and Mortality Among Pregnant Women With and Without COVID-19 Infection: The INTERCOVID Multinational Cohort Study

COVID-19 infection in pregnant women: Review of maternal and fetal outcomes

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

SARS-CoV2 vertical transmission with adverse effects on the newborn revealed through integrated immunohistochemical, electron microscopy and molecular analyses of Placenta

Harvard Neonatal-Perinatal Fellowship C-WG. COVID-19: neonatal-perinatal perspectives

Protein expression of angiotensin-converting enzyme 2, a SARS-CoV-2-specific receptor, in fetal and placental tissues throughout gestation: new insight for perinatal counseling

Single-Cell RNA-seq Identifies Cell Subsets in Human Placenta That Highly Expresses Factors Driving Pathogenesis of SARS-CoV-2

Maternal Coronavirus Infections and Neonates Born to Mothers with SARS-CoV-2: A Systematic Review

Maternal cytomegalovirus infection and perinatal transmission

Obstetric and neonatal outcomes after SARS-CoV-2 infection in the first trimester of pregnancy: A prospective comparative study

Maternal SARS-CoV-2 infection during pregnancy: possible impact on the infant

Effect of initial COVID-19 outbreak during first trimester on pregnancy outcome in Wuxi, China

A Possible Case of Vertical Transmission of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in a Newborn With Positive Placental In Situ Hybridization of SARS-CoV-2 RNA

COVID-19 FAQs for Obstetrician-Gynecologists, Obstetrics

Pregnancy Outcomes Among Women With and Without Severe Acute Respiratory Syndrome Coronavirus 2 Infection

Unbalance in Placentas from Mothers with SARS-CoV-2 Infection

Cellular and molecular atlas of the placenta from a COVID-19 pregnant woman infected at midgestation highlights the defective impacts on foetal health

Placental Pathology Findings during and after SARS-CoV-2 Infection: Features of Villitis and Malperfusion

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

Histopathologic evaluation of placentas after diagnosis of maternal severe acute respiratory syndrome coronavirus 2 infection

Placental SARS-CoV-2 in a pregnant woman with mild COVID-19 disease

Thirdtrimester placentas of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-positive women: histomorphology, including viral immunohistochemistry and in-situ hybridization

Synthesis and systematic review of reported neonatal SARS-CoV-2 infections

Clinical Characteristics of Mother-Infant Dyad and Placental Pathology in COVID-19 Cases in Predominantly African American Population

Clinical manifestations, risk factors, and maternal and perinatal outcomes of coronavirus disease 2019 in pregnancy: living systematic review and meta-analysis

Consequences and implications of the coronavirus disease (COVID-19) on pregnancy and newborns: A comprehensive systematic review and meta-analysis

The impact of COVID-19 on pregnancy outcomes in a diverse cohort in England

Detection of SARS-CoV-2 in Different Types of Clinical Specimens

Maternal and perinatal outcomes of pregnant women with SARS-CoV-2 infection at the time of birth in England: national cohort study

Pediatric Emergency Research Network C-ST. Outcomes of SARS-CoV-2-Positive Youths Tested in Emergency Departments: The Global PERN-COVID-19 Study

Epidemiology of COVID-19 infection in young children under five years: A systematic review and metaanalysis

Overcoming C-I. Frequency, Characteristics and Complications of COVID-19 in Hospitalized Infants

Clinical characteristics of children and young people admitted to hospital with covid-19 in United Kingdom: prospective multicentre observational cohort study

Neonates and COVID-19: state of the art : Neonatal Sepsis series

Clinical features and outcomes of coronavirus disease 2019 in early infants in Japan: A case series and literature review

Short-and mid-term multidisciplinary outcomes of newborns exposed to SARS-CoV-2 in utero or during the perinatal period: preliminary findings

Months in Infants With and Without In Utero Exposure to Maternal SARS-CoV-2 Infection

Association Between the COVID-19 Pandemic and Infant Neurodevelopment: A Comparison Before and During COVID-19

Breastfeeding mothers with COVID-19 infection: a case series

Experiences of breastfeeding during COVID-19: Lessons for future practical and emotional support

Kangaroo mother care to reduce morbidity and mortality in low birthweight infants

Parental perceptions of the impact of neonatal unit visitation policies during COVID-19 pandemic

Clinical characteristics and intrauterine vertical transmission potential of COVID-19 infection in nine pregnant women: a retrospective review of medical records

SARS-CoV-2 infection and neonates: Evidence-based data after 18 months of the pandemic

FAQs: Management of Infants Born to Mothers with Suspected or Confirmed COVID-19

Sick Newborn Care Collaborative G. 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

An observational study for appraisal of clinical outcome and risk of mother-to-child SARS-CoV-2 transmission in neonates provided the benefits of mothers' own milk

Characterization of SARS-CoV-2 RNA, Antibodies, and Neutralizing Capacity in Milk Produced by Women with COVID-19

COVID-19: neonatal-perinatal perspectives

Evaluation and Management Considerations for Neonates At Risk for COVID-19

Clinical management of COVID-19: Interim guidance

Consderations for Pregnancy, Breastfeeding, and COVID-19

EBCOG position statement on COVID-19 vaccination for pregnant and breastfeeding women

COVID-19 Vaccine Considerations during Pregnancy and Lactation

Modified mRNA Vaccines Protect against Zika Virus Infection

Vaccines and Related Biological Products Advisory Committee

Vaccines and Related Biological Products Advisory Committee Meeting FDA Briefing Document Janssen Ad.COV2.S Vaccine for the Prevention of COVID-19

Advisory Committee on Immunization Practices (ACIP): National Center for Immunization and Respiratory Diseases

V-safe COVID-19 Vaccine Pregnancy Registry

SARS-CoV-2-Specific Antibodies in Breast Milk After COVID-19 Vaccination of Breastfeeding Women

Immunogenicity of COVID-19 mRNA Vaccines in Pregnant and Lactating Women

Coronavirus disease 2019 vaccine response in pregnant and lactating women: a cohort study

Investigators OC-, Network OC-. Effectiveness of Maternal Vaccination with mRNA COVID-19 Vaccine During Pregnancy Against COVID-19-Associated Hospitalization in Infants Aged <6 Months -17 States

research continues to be critically necessary to optimize the outcomes of these vulnerable populations.

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.