[Skip to Content]
[Skip to Content Landing]

Assessment of Maternal and Neonatal SARS-CoV-2 Viral Load, Transplacental Antibody Transfer, and Placental Pathology in Pregnancies During the COVID-19 Pandemic

Educational Objective
To identify the key insights or developments described in this article
1 Credit CME
Key Points

Question  What key biological characteristics of maternal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and placental function and pathology have implications for vertical transmission and neonatal protection?

Findings  In this prospective cohort study including 127 pregnancies, there was no maternal viremia, placental infection, or vertical transmission of SARS-CoV-2. Compromised transplacental transfer of anti–SARS-CoV-2 antibodies with robust transfer of influenza-specific immunity and nonoverlapping placental expression of SARS-CoV-2 receptors angiotensin-converting enzyme 2 and transmembrane serine protease 2 were noted.

Meaning  These findings suggest that, although low rates of maternal viremia and patterns of placental SARS-CoV-2 receptor distribution may underlie the rarity of vertical transmission, reduced transplacental transfer of anti–SARS-CoV-2 antibodies may leave neonates at risk for infection.


Importance  Biological data are lacking with respect to risk of vertical transmission and mechanisms of fetoplacental protection in maternal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

Objective  To quantify SARS-CoV-2 viral load in maternal and neonatal biofluids, transplacental passage of anti–SARS-CoV-2 antibody, and incidence of fetoplacental infection.

Design, Setting, and Participants  This cohort study was conducted among pregnant women presenting for care at 3 tertiary care centers in Boston, Massachusetts. Women with reverse transcription–polymerase chain reaction (RT-PCR) results positive for SARS-CoV-2 were recruited from April 2 to June 13, 2020, and follow-up occurred through July 10, 2020. Contemporaneous participants without SARS-CoV-2 infection were enrolled as a convenience sample from pregnant women with RT-PCR results negative for SARS-CoV-2.

Exposures  SARS-CoV-2 infection in pregnancy, defined by nasopharyngeal swab RT-PCR.

Main Outcomes and Measures  The main outcomes were SARS-CoV-2 viral load in maternal plasma or respiratory fluids and umbilical cord plasma, quantification of anti–SARS-CoV-2 antibodies in maternal and cord plasma, and presence of SARS-CoV-2 RNA in the placenta.

Results  Among 127 pregnant women enrolled, 64 with RT-PCR results positive for SARS-CoV-2 (mean [SD] age, 31.6 [5.6] years) and 63 with RT-PCR results negative for SARS-CoV-2 (mean [SD] age, 33.9 [5.4] years) provided samples for analysis. Of women with SARS-CoV-2 infection, 23 (36%) were asymptomatic, 22 (34%) had mild disease, 7 (11%) had moderate disease, 10 (16%) had severe disease, and 2 (3%) had critical disease. In viral load analyses among 107 women, there was no detectable viremia in maternal or cord blood and no evidence of vertical transmission. Among 77 neonates tested in whom SARS-CoV-2 antibodies were quantified in cord blood, 1 had detectable immunoglobuilin M to nucleocapsid. Among 88 placentas tested, SARS-CoV-2 RNA was not detected in any. In antibody analyses among 37 women with SARS-CoV-2 infection, anti–receptor binding domain immunoglobin G was detected in 24 women (65%) and anti-nucleocapsid was detected in 26 women (70%). Mother-to-neonate transfer of anti–SARS-CoV-2 antibodies was significantly lower than transfer of anti-influenza hemagglutinin A antibodies (mean [SD] cord-to-maternal ratio: anti–receptor binding domain immunoglobin G, 0.72 [0.57]; anti-nucleocapsid, 0.74 [0.44]; anti-influenza, 1.44 [0.80]; P < .001). Nonoverlapping placental expression of SARS-CoV-2 receptors angiotensin-converting enzyme 2 and transmembrane serine protease 2 was noted.

Conclusions and Relevance  In this cohort study, there was no evidence of placental infection or definitive vertical transmission of SARS-CoV-2. Transplacental transfer of anti-SARS-CoV-2 antibodies was inefficient. Lack of viremia and reduced coexpression and colocalization of placental angiotensin-converting enzyme 2 and transmembrane serine protease 2 may serve as protective mechanisms against vertical transmission.

Sign in to take quiz and track your certificates

Buy This Activity

JN Learning™ is the home for CME and MOC from the JAMA Network. Search by specialty or US state and earn AMA PRA Category 1 Credit(s)™ from articles, audio, Clinical Challenges and more. Learn more about CME/MOC

CME Disclosure Statement: Unless noted, all individuals in control of content reported no relevant financial relationships. If applicable, all relevant financial relationships have been mitigated.

Article Information

Accepted for Publication: October 28, 2020.

Published: December 22, 2020. doi:10.1001/jamanetworkopen.2020.30455

Open Access: This is an open access article distributed under the terms of the CC-BY License. © 2020 Edlow AG et al. JAMA Network Open.

Corresponding Author: Andrea G. Edlow, MD, MSc, Vincent Center for Reproductive Biology, Massachusetts General Hospital, 55 Fruit St, Thier Research Building, 903B, Boston, MA 02114 (aedlow@mgh.harvard.edu).

Author Contributions: Dr Edlow had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. Drs Kaimal, Roberts, and Alter contributed equally to the work.

Concept and design: Edlow, Li, Collier, Boatin, Gray, Fasano, Devane, Matute, Lerou, Schmidt, Corry, Kaimal, Roberts, Alter.

Acquisition, analysis, or interpretation of data: Edlow, Li, Collier, Atyeo, James, Boatin, Bordt, Shook, Yonker, Fasano, Diouf, Croul, Devane, Yockey, Lima, Shui, Matute, Akinwunmi, Feldman, Hauser, Caradonna, De la Flor, D'Avino, Regan, Corry, Coxen, Fajnzylber, Pepin, Barouch, Seaman, Walker, Yu, Kaimal, Roberts, Alter.

Drafting of the manuscript: Edlow, Li, James, Devane, Akinwunmi, Pepin, Roberts, Alter.

Critical revision of the manuscript for important intellectual content: Edlow, Li, Collier, Atyeo, James, Boatin, Gray, Bordt, Shook, Yonker, Fasano, Diouf, Croul, Devane, Yockey, Lima, Shui, Matute, Lerou, Schmidt, Feldman, Hauser, Caradonna, De la Flor, D'Avino, Regan, Corry, Coxen, Fajnzylber, Pepin, Barouch, Seaman, Walker, Yu, Kaimal, Roberts, Alter.

Statistical analysis: Edlow, Collier, Atyeo, James, Bordt, De la Flor, Pepin, Alter.

Obtained funding: Edlow, Li, Yonker, Fasano, Schmidt, Yu, Kaimal, Alter.

Administrative, technical, or material support: Edlow, Li, Collier, Boatin, Gray, Shook, Yonker, Fasano, Diouf, Croul, Devane, Yockey, Lima, Matute, Lerou, Akinwunmi, Feldman, Hauser, Caradonna, D'Avino, Coxen, Pepin, Barouch, Seaman, Yu, Kaimal, Roberts, Alter.

Supervision: Edlow, Collier, Gray, Lerou, De la Flor, Pepin, Barouch, Walker, Kaimal, Alter.

Conflict of Interest Disclosures: Dr Li reported serving as a consultant for Abbvie and Jan Biotech. Dr Boatin reported serving as a consultant for Microchips Biotech and as a scientific advisory board member for Reproductive Health Investors Alliance. Dr Gray reported receiving nonfinancial support from Illumina, and personal fees from Quest Diagnostics, BillionToOne, and Aetion outside the submitted work. Dr Fasano reported serving as a cofounder of and owning stock in Alba Therapeutics and serving on scientific advisory boards for NextCure and Viome outside the submitted work. Dr Schmidt reported receiving grants from the Bill and Melinda Gates Foundation, Defense Advanced Research Projects Agency (DARPA), Henry Jackson Foundation, amfAR, Ragon Institute, Massachusetts Consortium on Pathogen Readiness, Janssen, Gilead, Legend, Sanofi, Zentalis, Alkermes, and Intima; personal fees from SQZ Biotech; and having a patent for a SARS-CoV-2 vaccine licensed to Janssen. Dr Pepin reported owning stock in Gilead Sciences, BioNano Genomics, Biogen, Bluebird Bio, ImmunoGen, Pfizer, and Bristol-Myers Squibb. Dr Kaimal reported receiving grants from the National Institutes of Health outside the submitted work. Dr Roberts reported receiving author royalties from UpToDate and Cambridge University Press outside the submitted work. Dr Alter reported serving as a founder of Systems Seromyx. No other disclosures were reported.

Funding/Support: This work was supported by the National Institutes of Health, including NICHD (grants R01HD100022 and 3R01HD100022-02S2 [Dr Edlow], K12HD000849 [Dr Collier], and K23HD097300 [Dr Boatin]); National Heart, Lung, and Blood Institute (grants K08 HL146963 [Dr Gray] and K08 HL143183 [Dr Yonker]); and National Institute of Allergy and Infectious Diseases (grant No. R01 AI146779 [Dr Schmidt]). Support was also provided by the Cystic Fibrosis Foundation (grant No. YONKER18Q0 [Dr Yonker]), a gift from Mark, Lisa, and Enid Schwartz (Dr Li), and by the MGH Department of Pathology Vickery-Colvin award. Additional support was provided by the Ragon Institute of MGH and MIT, Massachusetts General Hospital Department of Obstetrics and Gynecology, Massachusetts Consortium on Pathogen Readiness, the Evergrande Fund, the Bill and Melinda Gates Foundation (grant No. 235730), and the Harvard Center for AIDS Research (grant No. P30 AI060354-11).

Role of the Funder/Sponsor: The funders had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

Additional Contributions: Dana Cvrk, CNM, Muriel Schwinn, NP, Robin Azevedo, RN, Laurel Gardner, RN, Suzanne Stanton, RN, Ricardo Aguayo, BS, Annika Gompers, MPhil, Alec Brown, BA, and Laurie P. Foster, RN, provided critical assistance with participant recruitment. Nancy Zimmerman, BA, Mark Schwartz, BA, MBA, Lisa Schwartz, BA, MBA, Terry Ragon, BA, and Susan Ragon, BA, and Jeffrey Ecker, MD, provided early material support. Bing Chen, PhD, assisted with protein production. Marie-Charlotte Meinsohn, PhD, Ngoc Minh Phuong Nguyen, PhD, and Maeva Chauvin, PhD, assisted with the SARS-CoV-2 placental in situ hybridization. Noe B. Mercado, BS, and Catherine Jacob-Dolan, BS, assisted with viral load assays. Ms Azevedo, Gardner, and Stanton received compensation for time worked on the study.

Ellington  S , Strid  P , Tong  VT ,  et al.  Characteristics of women of reproductive age with laboratory-confirmed SARS-CoV-2 infection by pregnancy status—United States, January 22-June 7, 2020.   MMWR Morb Mortal Wkly Rep. 2020;69(25):769-775. doi:10.15585/mmwr.mm6925a1 PubMedGoogle ScholarCrossref
Khalil  A , von Dadelszen  P , Draycott  T , Ugwumadu  A , O’Brien  P , Magee  L .  Change in the incidence of stillbirth and preterm delivery during the COVID-19 pandemic.   JAMA. 2020;324(7):705-706. doi:10.1001/jama.2020.12746 PubMedGoogle ScholarCrossref
Takemoto  MLS , Menezes  MO , Andreucci  CB ,  et al.  The tragedy of COVID-19 in Brazil: 124 maternal deaths and counting.   Int J Gynaecol Obstet. 2020. doi:10.1002/ijgo.13300 PubMedGoogle Scholar
Liu  H , Wang  LL , Zhao  SJ , Kwak-Kim  J , Mor  G , Liao  AH .  Why are pregnant women susceptible to COVID-19? an immunological viewpoint.   J Reprod Immunol. 2020;139:103122. doi:10.1016/j.jri.2020.103122 PubMedGoogle Scholar
Dashraath  P , Wong  JLJ , Lim  MXK ,  et al.  Coronavirus disease 2019 (COVID-19) pandemic and pregnancy.   Am J Obstet Gynecol. 2020;222(6):521-531. doi:10.1016/j.ajog.2020.03.021 PubMedGoogle ScholarCrossref
Alberca  RW , Pereira  NZ , Oliveira  LMDS , Gozzi-Silva  SC , Sato  MN .  Pregnancy, viral infection, and COVID-19.   Front Immunol. 2020;11:1672. doi:10.3389/fimmu.2020.01672 PubMedGoogle ScholarCrossref
Schwartz  DA , Graham  AL .  Potential maternal and infant outcomes from (Wuhan) coronavirus 2019-nCoV infecting pregnant women: lessons from SARS, MERS, and other human coronavirus infections.   Viruses. 2020;12(2):12. doi:10.3390/v12020194 PubMedGoogle ScholarCrossref
Baergen  RN , Heller  DS .  Placental pathology in Covid-19 positive mothers: preliminary findings.   Pediatr Dev Pathol. 2020;23(3):177-180. doi:10.1177/1093526620925569 PubMedGoogle ScholarCrossref
Chen  H , Guo  J , Wang  C ,  et al.  Clinical characteristics and intrauterine vertical transmission potential of COVID-19 infection in nine pregnant women: a retrospective review of medical records.   Lancet. 2020;395(10226):809-815. doi:10.1016/S0140-6736(20)30360-3 PubMedGoogle ScholarCrossref
Dong  L , Tian  J , He  S ,  et al.  Possible vertical transmission of SARS-CoV-2 from an infected mother to her newborn.   JAMA. 2020;323(18):1846-1848. doi:10.1001/jama.2020.4621 PubMedGoogle Scholar
Fenizia  C , Biasin  M , Cetin  I .  In utero mother-to-child SARS-CoV-2 transmission: viral detection and fetal immune response.   medRxiv. Preprint posted online July 10, 2020. doi:10.1101/2020.07.09.2014959Google Scholar
Hosier  H , Farhadian  S , Morotti  R ,  et al.  SARS-CoV-2 infection of the placenta.   medRxiv. Preprint posted online May 12, 2020. doi:10.1172/JCI139569Google Scholar
Patanè  L , Morotti  D , Giunta  MR ,  et al.  Vertical transmission of COVID-19: SARS-CoV-2 RNA on the fetal side of the placenta in pregnancies with COVID-19 positive mothers and neonates at birth.   Am J Obstet Gynecol MFM. 2020;100145. doi:10.1016/j.ajogmf.2020.100145PubMedGoogle Scholar
Penfield  CA , Brubaker  SG , Limaye  MA ,  et al.  Detection of SARS-COV-2 in placental and fetal membrane samples.   Am J Obstet Gynecol MFM. 2020;100133. doi:10.1016/j.ajogmf.2020.100133 PubMedGoogle Scholar
Shanes  ED , Mithal  LB , Otero  S , Azad  HA , Miller  ES , Goldstein  JA .  Placental pathology in COVID-19.   Am J Clin Pathol. 2020;154(1):23-32. doi:10.1093/ajcp/aqaa089 PubMedGoogle ScholarCrossref
Chen  S , Huang  B , Luo  DJ ,  et al.  Pregnancy with new coronavirus infection: clinical characteristics and placental pathological analysis of three cases  [Article in Chinese].  Zhonghua Bing Li Xue Za Zhi. 2020;49(5):418-423. doi:10.3760/cma.j.cn112151-20200225-00138PubMedGoogle Scholar
Lamouroux  A , Attie-Bitach  T , Martinovic  J , Leruez-Ville  M , Ville  Y .  Evidence for and against vertical transmission for severe acute respiratory syndrome coronavirus 2.   Am J Obstet Gynecol. 2020;223(1):91.e1-91.e4. doi:10.1016/j.ajog.2020.04.039 PubMedGoogle ScholarCrossref
Alzamora  MC , Paredes  T , Caceres  D , Webb  CM , Valdez  LM , La Rosa  M .  Severe COVID-19 during pregnancy and possible vertical transmission.   Am J Perinatol. 2020;37(8):861-865. doi:10.1055/s-0040-1710050 PubMedGoogle ScholarCrossref
Zeng  H , Xu  C , Fan  J ,  et al.  Antibodies in infants born to mothers with COVID-19 pneumonia.   JAMA. 2020;323(18):1848-1849. doi:10.1001/jama.2020.4861 PubMedGoogle Scholar
Vivanti  AJ , Vauloup-Fellous  C , Prevot  S ,  et al.  Transplacental transmission of SARS-CoV-2 infection.   Nat Commun. 2020;11(1):3572. doi:10.1038/s41467-020-17436-6 PubMedGoogle ScholarCrossref
Society for Maternal-Fetal Medicine. Management considerations for pregnant patients with COVID-19. Updated July 2, 2020. Accessed July 3, 2020, 2020. https://s3.amazonaws.com/cdn.smfm.org/media/2415/SMFM_COVID_Management_of_COVID_pos_preg_patients_7-2-20.PDF_.pdf
Centers for Disease Control and Prevention. Severe maternal morbidity in the United States. Accessed July 7, 2020. https://www.cdc.gov/reproductivehealth/maternalinfanthealth/severematernalmorbidity.html
Kilpatrick  SK , Ecker  JL ; American College of Obstetricians and Gynecologists and the Society for Maternal–Fetal Medicine.  Severe maternal morbidity: screening and review.   Am J Obstet Gynecol. 2016;215(3):B17-B22. doi:10.1016/j.ajog.2016.07.050 PubMedGoogle ScholarCrossref
Chauhan  SP , Rice  MM , Grobman  WA ,  et al; MSCE, for the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Maternal-Fetal Medicine Units (MFMU) Network.  Neonatal morbidity of small- and large-for-gestational-age neonates born at term in uncomplicated pregnancies.   Obstet Gynecol. 2017;130(3):511-519. doi:10.1097/AOG.0000000000002199 PubMedGoogle ScholarCrossref
Fajnzylber  JM , Regan  J , Coxen  K ,  et al.  SARS-CoV-2 viral load is associated with increased disease severity and mortality.   medRxiv. Preprint posted online July 17, 2020. doi:10.1101/2020.07.15.20131789Google Scholar
Centers for Disease Control and Prevention. Research use only 2019-Novel Coronavirus (2019-nCoV) real-time RT-PCR primers and probes. Accessed April 2, 2020. https://www.cdc.gov/coronavirus/2019-ncov/lab/rt-pcr-panel-primer-probes.html
Khong  TY , Mooney  EE , Ariel  I ,  et al.  Sampling and definitions of placental lesions: Amsterdam Placental Workshop Group consensus statement.   Arch Pathol Lab Med. 2016;140(7):698-713. doi:10.5858/arpa.2015-0225-CC PubMedGoogle ScholarCrossref
Saatcioglu  HD , Kano  M , Horn  H ,  et al.  Single-cell sequencing of neonatal uterus reveals an Misr2+ endometrial progenitor indispensable for fertility.   Elife. 2019;8:8. doi:10.7554/eLife.46349 PubMedGoogle ScholarCrossref
Wang  F , Flanagan  J , Su  N ,  et al.  RNAscope: a novel in situ RNA analysis platform for formalin-fixed, paraffin-embedded tissues.   J Mol Diagn. 2012;14(1):22-29. doi:10.1016/j.jmoldx.2011.08.002 PubMedGoogle ScholarCrossref
Hecht  JL , Quade  B , Deshpande  V ,  et al.  SARS-CoV-2 can infect the placenta and is not associated with specific placental histopathology: a series of 19 placentas from COVID-19-positive mothers.   Mod Pathol. 2020;33(11):2092-2103. doi:10.1038/s41379-020-0639-4 PubMedGoogle ScholarCrossref
Hoffmann  M , Kleine-Weber  H , Schroeder  S ,  et al.  SARS-CoV-2 cell entry depends on ACE2 and TMPRSS2 and is blocked by a clinically proven protease inhibitor.   Cell. 2020;181(2):271-280.e8. doi:10.1016/j.cell.2020.02.052 PubMedGoogle ScholarCrossref
Flaherman  VJ , Afshar  Y , Boscardin  J ,  et al.  Infant outcomes following maternal infection with SARS-CoV-2: first report from the PRIORITY Study.   Clin Infect Dis. 2020;ciaa1411. doi:10.1093/cid/ciaa1411 PubMedGoogle Scholar
Chen  X , Zhao  B , Qu  Y ,  et al.  Detectable serum SARS-CoV-2 viral load (RNAaemia) is closely correlated with drastically elevated interleukin 6 (IL-6) level in critically ill COVID-19 patients.   Clin Infect Dis. 2020;ciaa449. PubMedGoogle Scholar
Huang  C , Wang  Y , Li  X ,  et al.  Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China.   Lancet. 2020;395(10223):497-506. doi:10.1016/S0140-6736(20)30183-5 PubMedGoogle ScholarCrossref
Kay  AW , Fukuyama  J , Aziz  N ,  et al.  Enhanced natural killer-cell and T-cell responses to influenza A virus during pregnancy.   Proc Natl Acad Sci U S A. 2014;111(40):14506-14511. doi:10.1073/pnas.1416569111 PubMedGoogle ScholarCrossref
Wells  AI , Coyne  CB .  Type III interferons in antiviral defenses at barrier surfaces.   Trends Immunol. 2018;39(10):848-858. doi:10.1016/j.it.2018.08.008 PubMedGoogle ScholarCrossref
Wölfel  R , Corman  VM , Guggemos  W ,  et al.  Virological assessment of hospitalized patients with COVID-2019.   Nature. 2020;581(7809):465-469. doi:10.1038/s41586-020-2196-x PubMedGoogle ScholarCrossref
Jamal  AJ , Mozafarihashjin  M , Coomes  E ,  et al; Toronto Invasive Bacterial Diseases Network COVID-19 Investigators.  Sensitivity of nasopharyngeal swabs and saliva for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).   Clin Infect Dis. 2020;ciaa848. doi:10.1093/cid/ciaa848 PubMedGoogle Scholar
Péré  H , Podglajen  I , Wack  M ,  et al.  Nasal swab sampling for SARS-CoV-2: a convenient alternative in times of nasopharyngeal swab shortage.   J Clin Microbiol. 2020;58(6):58. doi:10.1128/JCM.00721-20 PubMedGoogle ScholarCrossref
Tu  YP , Jennings  R , Hart  B ,  et al.  Swabs collected by patients or health care workers for SARS-CoV-2 testing.   N Engl J Med. 2020;383(5):494-496. doi:10.1056/NEJMc2016321 PubMedGoogle ScholarCrossref
Wang  W , Xu  Y , Gao  R ,  et al.  Detection of SARS-CoV-2 in different types of clinical specimens.   JAMA. 2020;323(18):1843-1844. doi:10.1001/jama.2020.3786 PubMedGoogle Scholar
Gonçalves  G , Cutts  FT , Hills  M , Rebelo-Andrade  H , Trigo  FA , Barros  H .  Transplacental transfer of measles and total IgG.   Epidemiol Infect. 1999;122(2):273-279. doi:10.1017/S0950268899002046 PubMedGoogle ScholarCrossref
Heininger  U , Riffelmann  M , Leineweber  B , Wirsing von Koenig  CH .  Maternally derived antibodies against Bordetella pertussis antigens pertussis toxin and filamentous hemagglutinin in preterm and full term newborns.   Pediatr Infect Dis J. 2009;28(5):443-445. doi:10.1097/INF.0b013e318193ead7 PubMedGoogle ScholarCrossref
Munoz  FM , Bond  NH , Maccato  M ,  et al.  Safety and immunogenicity of tetanus diphtheria and acellular pertussis (Tdap) immunization during pregnancy in mothers and infants: a randomized clinical trial.   JAMA. 2014;311(17):1760-1769. doi:10.1001/jama.2014.3633 PubMedGoogle ScholarCrossref
Gao  J , Li  W , Hu  X ,  et al.  Disappearance of SARS-CoV-2 antibodies in infants born to women with COVID-19, Wuhan, China.   Emerg Infect Dis. 2020;26(10):2491-2494. doi:10.3201/eid2610.202328 PubMedGoogle ScholarCrossref
Hammond  SN , Balmaseda  A , Pérez  L ,  et al.  Differences in dengue severity in infants, children, and adults in a 3-year hospital-based study in Nicaragua.   Am J Trop Med Hyg. 2005;73(6):1063-1070. doi:10.4269/ajtmh.2005.73.1063 PubMedGoogle ScholarCrossref
Pengsaa  K , Luxemburger  C , Sabchareon  A ,  et al.  Dengue virus infections in the first 2 years of life and the kinetics of transplacentally transferred dengue neutralizing antibodies in Thai children.   J Infect Dis. 2006;194(11):1570-1576. doi:10.1086/508492 PubMedGoogle ScholarCrossref
Simmons  CP , Chau  TN , Thuy  TT ,  et al.  Maternal antibody and viral factors in the pathogenesis of dengue virus in infants.   J Infect Dis. 2007;196(3):416-424. doi:10.1086/519170 PubMedGoogle ScholarCrossref
Cumberland  P , Shulman  CE , Maple  PA ,  et al.  Maternal HIV infection and placental malaria reduce transplacental antibody transfer and tetanus antibody levels in newborns in Kenya.   J Infect Dis. 2007;196(4):550-557. doi:10.1086/519845 PubMedGoogle ScholarCrossref
Ogolla  S , Daud  II , Asito  AS ,  et al.  Reduced transplacental transfer of a subset of Epstein-Barr virus-specific antibodies to neonates of mothers infected with Plasmodium falciparum malaria during pregnancy.   Clin Vaccine Immunol. 2015;22(11):1197-1205. doi:10.1128/CVI.00270-15 PubMedGoogle ScholarCrossref
Ray  JE , Dobbs  KR , Ogolla  SO ,  et al.  Reduced transplacental transfer of antimalarial antibodies in Kenyan HIV-exposed uninfected infants.   Open Forum Infect Dis. 2019;6(6):ofz237. doi:10.1093/ofid/ofz237 PubMedGoogle Scholar
Kim  L , Whitaker  M , O’Halloran  A ,  et al; COVID-NET Surveillance Team.  Hospitalization rates and characteristics of children aged <18 years hospitalized with laboratory-confirmed COVID-19—COVID-NET, 14 states, March 1-July 25, 2020.   MMWR Morb Mortal Wkly Rep. 2020;69(32):1081-1088. doi:10.15585/mmwr.mm6932e3 PubMedGoogle ScholarCrossref
Ben-Hur  H , Gurevich  P , Elhayany  A , Avinoach  I , Schneider  DF , Zusman  I .  Transport of maternal immunoglobulins through the human placental barrier in normal pregnancy and during inflammation.   Int J Mol Med. 2005;16(3):401-407. doi:10.3892/ijmm.16.3.401 PubMedGoogle Scholar
Pique-Regi  R , Romero  R , Tarca  AL ,  et al.  Does the human placenta express the canonical cell entry mediators for SARS-CoV-2?   Elife. 2020;9:e58716. doi:10.7554/eLife.58716 PubMedGoogle Scholar
Goldfarb  IT , Clapp  MA , Soffer  MD ,  et al.  Prevalence and severity of coronavirus disease 2019 (COVID-19) illness in symptomatic pregnant and postpartum women stratified by Hispanic ethnicity.   Obstet Gynecol. 2020;136(2):300-302. doi:10.1097/AOG.0000000000004005 PubMedGoogle ScholarCrossref
Pentsuk  N , van der Laan  JW .  An interspecies comparison of placental antibody transfer: new insights into developmental toxicity testing of monoclonal antibodies.   Birth Defects Res B Dev Reprod Toxicol. 2009;86(4):328-344. doi:10.1002/bdrb.20201 PubMedGoogle ScholarCrossref
Garty  BZ , Ludomirsky  A , Danon  YL , Peter  JB , Douglas  SD .  Placental transfer of immunoglobulin G subclasses.   Clin Diagn Lab Immunol. 1994;1(6):667-669. doi:10.1128/CDLI.1.6.667-669.1994 PubMedGoogle ScholarCrossref
Ciobanu  AM , Dumitru  AE , Gica  N , Botezatu  R , Peltecu  G , Panaitescu  AM .  Benefits and risks of IgG transplacental transfer.   Diagnostics (Basel). 2020;10(8):10.PubMedGoogle Scholar
Zhong  Z , Haltalli  M , Holder  B ,  et al.  The impact of timing of maternal influenza immunization on infant antibody levels at birth.   Clin Exp Immunol. 2019;195(2):139-152. doi:10.1111/cei.13234 PubMedGoogle ScholarCrossref
Abu Raya  B , Srugo  I , Kessel  A ,  et al.  The effect of timing of maternal tetanus, diphtheria, and acellular pertussis (Tdap) immunization during pregnancy on newborn pertussis antibody levels: a prospective study.   Vaccine. 2014;32(44):5787-5793. doi:10.1016/j.vaccine.2014.08.038 PubMedGoogle ScholarCrossref
Eberhardt  CS , Blanchard-Rohner  G , Lemaître  B ,  et al.  Maternal immunization earlier in pregnancy maximizes antibody transfer and expected infant seropositivity against pertussis.   Clin Infect Dis. 2016;62(7):829-836. doi:10.1093/cid/ciw027 PubMedGoogle ScholarCrossref
Healy  CM , Munoz  FM , Rench  MA , Halasa  NB , Edwards  KM , Baker  CJ .  Prevalence of pertussis antibodies in maternal delivery, cord, and infant serum.   J Infect Dis. 2004;190(2):335-340. doi:10.1086/421033 PubMedGoogle ScholarCrossref
Castanha  PMS , Souza  WV , Braga  C ,  et al; Microcephaly Epidemic Research Group.  Perinatal analyses of Zika- and dengue virus–specific neutralizing antibodies: a microcephaly case-control study in an area of high dengue endemicity in Brazil.   PLoS Negl Trop Dis. 2019;13(3):e0007246. doi:10.1371/journal.pntd.0007246 PubMedGoogle Scholar
Collier  AY , Borducchi  EN , Chandrashekar  A ,  et al.  Sustained maternal antibody and cellular immune responses in pregnant women infected with Zika virus and mother to infant transfer of Zika-specific antibodies.   Am J Reprod Immunol. 2020;e13288. doi:10.1111/aji.13288 PubMedGoogle Scholar
Singh  T , Lopez  CA , Giuberti  C ,  et al.  Efficient transplacental IgG transfer in women infected with Zika virus during pregnancy.   PLoS Negl Trop Dis. 2019;13(8):e0007648. doi:10.1371/journal.pntd.0007648 PubMedGoogle Scholar
Castanha  PM , Braga  C , Cordeiro  MT ,  et al.  Placental transfer of dengue virus (DENV)-specific antibodies and kinetics of DENV infection-enhancing activity in Brazilian infants.   J Infect Dis. 2016;214(2):265-272. doi:10.1093/infdis/jiw143 PubMedGoogle ScholarCrossref
Boulanger-Bertolus  J , Pancaro  C , Mashour  GA .  Increasing role of maternal immune activation in neurodevelopmental disorders.   Front Behav Neurosci. 2018;12:230. doi:10.3389/fnbeh.2018.00230 PubMedGoogle ScholarCrossref
Estes  ML , McAllister  AK .  Maternal immune activation: implications for neuropsychiatric disorders.   Science. 2016;353(6301):772-777. doi:10.1126/science.aag3194 PubMedGoogle ScholarCrossref
Schepanski  S , Buss  C , Hanganu-Opatz  IL , Arck  PC .  Prenatal immune and endocrine modulators of offspring’s brain development and cognitive functions later in life.   Front Immunol. 2018;9:2186. doi:10.3389/fimmu.2018.02186 PubMedGoogle ScholarCrossref
AMA CME Accreditation Information

Credit Designation Statement: The American Medical Association designates this Journal-based CME activity activity for a maximum of 1.00  AMA PRA Category 1 Credit(s)™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Successful completion of this CME activity, which includes participation in the evaluation component, enables the participant to earn up to:

  • 1.00 Medical Knowledge MOC points in the American Board of Internal Medicine's (ABIM) Maintenance of Certification (MOC) program;;
  • 1.00 Self-Assessment points in the American Board of Otolaryngology – Head and Neck Surgery’s (ABOHNS) Continuing Certification program;
  • 1.00 MOC points in the American Board of Pediatrics’ (ABP) Maintenance of Certification (MOC) program;
  • 1.00 Lifelong Learning points in the American Board of Pathology’s (ABPath) Continuing Certification program; and
  • 1.00 CME points in the American Board of Surgery’s (ABS) Continuing Certification program

It is the CME activity provider's responsibility to submit participant completion information to ACCME for the purpose of granting MOC credit.

Want full access to the AMA Ed Hub?
After you sign up for AMA Membership, make sure you sign in or create a Physician account with the AMA in order to access all learning activities on the AMA Ed Hub
Buy this activity
Want full access to the AMA Ed Hub?
After you sign up for AMA Membership, make sure you sign in or create a Physician account with the AMA in order to access all learning activities on the AMA Ed Hub
Buy this activity
With a personal account, you can:
  • Access free activities and track your credits
  • Personalize content alerts
  • Customize your interests
  • Fully personalize your learning experience
Education Center Collection Sign In Modal Right

Name Your Search

Save Search
With a personal account, you can:
  • Access free activities and track your credits
  • Personalize content alerts
  • Customize your interests
  • Fully personalize your learning experience

Lookup An Activity


My Saved Searches

You currently have no searches saved.


My Saved Courses

You currently have no courses saved.