title: Primary versus non-primary maternal cytomegalovirus infection as a cause of symptomatic congenital infection - register-based study from Finland.
abstract: BACKGROUND
  Both primary and non-primary maternal cytomegalovirus (CMV) infection during pregnancy can lead to vertical transmission. We evaluated the proportion of maternal primary/non-primary infections among 26 babies with symptomatic congenital CMV infection born in Finland from 2000 to 2012.
  
  
  METHODS
  We executed a database search on hospital records from all five university hospitals in Finland to identify infants with congenital CMV infection. The preserved maternal serum samples drawn at the end of the first trimester were analysed for CMV antibodies. Maternal infection was classified to be non-primary, if there was high avidity CMV immunoglobulin G (IgG) in the early pregnancy samples. Infection was considered primary in the case of either low avidity IgG (primary infection in the first trimester or near conception) or absent CMV IgG at the end of the first trimester (primary infection in the second or third trimester).
  
  
  RESULTS
  The majority of the symptomatic congenital CMV infections (54%) were due to maternal non-primary infection, 27% due to maternal primary infection in the first trimester or near conception, and 19% during the second or third trimester. Long-term sequelae occurred in 59% of patients: in 6/7 after primary infection in the first trimester, in 0/5 after primary infection in the second or third trimester, and in 9/14 after non-primary infection.
  
  
  CONCLUSIONS
  In this register-based cohort, non-primary infections caused the majority of symptomatic congenital CMV infections, and resulted in significant morbidity.
authors.affiliation: a Pediatrics , Children's Hospital, University of Helsinki and Helsinki University Hospital , Helsinki , Finland.
authors.forename: Laura
authors.initials: L
authors.lastname: Puhakka
authors.affiliation: b Pediatrics, PEDEGO Research Unit , University of Oulu and Oulu University Hospital , Oulu , Finland.
authors.forename: Marjo
authors.initials: M
authors.lastname: Renko
authors.affiliation: c Pediatrics , Tampere University and University Hospital , Tampere , Finland.
authors.forename: Merja
authors.initials: M
authors.lastname: Helminen
authors.affiliation: d Department of Pediatrics and Adolescent Medicine , Turku University Hospital and University of Turku , Turku , Finland.
authors.forename: Ville
authors.initials: V
authors.lastname: Peltola
authors.affiliation: e Pediatrics , Kuopio University Hospital , Kuopio , Finland.
authors.forename: Tarja
authors.initials: T
authors.lastname: Heiskanen-Kosma
authors.affiliation: f Laboratory Services (HUSLAB), Division of Clinical Microbiology , University of Helsinki and Helsinki University Hospital , Helsinki , Finland.
authors.forename: Maija
authors.initials: M
authors.lastname: Lappalainen
authors.affiliation: g National Institute for Health and Welfare (THL) , Oulu , Finland.
authors.forename: Heljä-Marja
authors.initials: HM
authors.lastname: Surcel
authors.affiliation: h Pediatric Neurology , Children's Hospital, University of Helsinki and Helsinki University Hospital , Helsinki , Finland.
authors.forename: Tuula
authors.initials: T
authors.lastname: Lönnqvist
authors.affiliation: i Infectious Diseases , Children's Hospital, University of Helsinki and Helsinki University Hospital , Helsinki , Finland.
authors.forename: Harri
authors.initials: H
authors.lastname: Saxen
mesh_terms: D000293:Adolescent; D000914:Antibodies, Viral / Q000097:blood*; D003587:Cytomegalovirus / Q000276:immunology / Q000302:isolation & purification; D003586:Cytomegalovirus Infections / Q000151:congenital* / Q000453:epidemiology / Q000209:etiology* / Q000821:virology; D005260:Female; D005315:Fetal Diseases / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000276:immunology / Q000821:virology*; D005387:Finland / Q000453:epidemiology; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D007136:Immunoglobulins / Q000097:blood; D016756:Immunoglobulins, Intravenous; D007223:Infant; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000453:epidemiology / Q000821:virology*; D012042:Registries; D012189:Retrospective Studies; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D055815:Young Adult
chemical_list: D000914:Antibodies, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007136:Immunoglobulins; D016756:Immunoglobulins, Intravenous; C045781:cytomegalovirus-specific hyperimmune globulin
keywords: Congenital; cytomegalovirus; non-primary infection; primary infection; sequelae