title: Paternal and maternal carriage of the annexin A5 M2 haplotype are equal risk factors for recurrent pregnancy loss: a pilot study.
abstract: OBJECTIVE
  To study the possible contribution of paternal, in addition to maternal, carriage of M2/ANXA5 as a risk factor for recurrent pregnancy loss (RPL).
  
  
  METHODS
  Case-control study.
  
  
  METHODS
  Academic research center.
  
  
  METHODS
  Couples presenting themselves to the Fertility Center, Ludwig-Maximilians-University Munich with two or more consecutive, unexplained miscarriages were selected for this study. Fertile female controls were from the same center and also from the resource of the Institute of Human Genetics, Westfalian Wilhelms-University Muenster. Population controls were drafted from the PopGen biobank, University Clinic Schleswig-Holstein Kiel.
  
  
  METHODS
  None.
  
  
  METHODS
  Incidence of M2 carriage was estimated in patient and control groups, odds ratios were calculated, and RPL risk was evaluated.
  
  
  RESULTS
  In comparison with female fertile controls, the risk for repeated abortion in the RPL group, associated with M2 carriage, was between 1.7 and 3.8, and it was 2.3 compared with population controls. Because of the equal genetic incidence of M2, with an allelic frequency of 0.167 in the female and male partner RPL subgroups, the haplotype confers approximately the same relative risk to carriers of both sexes.
  
  
  CONCLUSIONS
  Paternal M2 carriage seems to confer an equal risk for recurrent miscarriages as M2 carriage in RPL mothers. This finding points to a role of ANXA5 and the M2 haplotype in the fetus and/or the extraembryonic membranes for pregnancy pathology. Prognostic RPL algorithms might be improved by testing the male partner for M2 carriage, and this may guide adequate therapeutic decisions.
authors.affiliation: Division of Gynecological Endocrinology and Reproductive Medicine, Department of Gynecology and Obstetrics, Clinical Center of Ludwig-Maximilians-University, Munich, Germany.
authors.forename: Nina
authors.initials: N
authors.lastname: Rogenhofer
authors.forename: Laura
authors.initials: L
authors.lastname: Engels
authors.forename: Nadja
authors.initials: N
authors.lastname: Bogdanova
authors.forename: Frank
authors.initials: F
authors.lastname: Tüttelmann
authors.forename: Arseni
authors.initials: A
authors.lastname: Markoff
authors.forename: Christian
authors.initials: C
authors.lastname: Thaler
mesh_terms: D000026:Abortion, Habitual / Q000209:etiology* / Q000235:genetics* / Q000473:pathology; D000328:Adult; D017304:Annexin A5 / Q000235:genetics*; D016022:Case-Control Studies; D005260:Female; D006239:Haplotypes / Q000235:genetics*; D006579:Heterozygote; D006801:Humans; D008297:Male; D010865:Pilot Projects; D011247:Pregnancy; D012307:Risk Factors; D055815:Young Adult
chemical_list: D017304:Annexin A5