title: Thrombophilic polymorphisms and intrauterine growth restriction.
abstract: BACKGROUND
  The relationship between thrombophilic polymorphisms and intrauterine growth restriction remains unclear. Whereas a subset of these polymorphisms have received some attention, others have not.
  
  
  METHODS
  We conducted a case-control study of 493 cases of intrauterine growth restriction (birthweight less than the 10th percentile for gestational age and sex) and 472 controls (greater than the 10th percentile). We also conducted a family study including approximately 250 case trios (affected newborn, mother, and father) for each studied gene. Plasminogen activator inhibitor-1(PAI-1) 4G/5G and Factor XIII Val134Leu variants were compared between maternal and newborn cases and controls. Relative risks for newborn and maternal PAI-1 and Factor XIII genotypes in case trios were estimated using a log-linear model. Transmission of MTHFR C677T and 1298C haplotypes was analyzed in case trios, and the estimated haplotype distribution compared between cases and controls. Finally, we explored pairwise gene-gene interactions between all measured polymorphisms, including Factor V Leiden G1691A and Prothrombin G20210A.
  
  
  RESULTS
  PAI-1 and Factor XIII polymorphisms were not associated with an increased risk of intrauterine growth restriction in the case-control analysis, and the case-parent analysis showed no newborn or maternal excess genotype relative risk. No excess transmission of the MTHFR haplotypes was observed in case newborns, and the distribution of MTHFR haplotypes was similar between cases and controls. Some results were suggestive of interactions between genes.
  
  
  CONCLUSIONS
  Overall, there seems to be little or no indication that thrombophilic genes, at least individually, have an effect on intrauterine growth restriction.
authors.affiliation: Department of Epidemiology, Biostatistics, and Occupational Health, Faculty of Medicine, McGill University, 1130 Pine Avenue West, Montréal, Province of Quebec, Canada H31 1A3. claire.infante-rivard@mcgill.ca
authors.forename: Claire
authors.initials: C
authors.lastname: Infante-Rivard
authors.forename: Georges-Etienne
authors.initials: GE
authors.lastname: Rivard
authors.forename: Marguerite
authors.initials: M
authors.lastname: Guiguet
authors.forename: Robert
authors.initials: R
authors.lastname: Gauthier
mesh_terms: D016022:Case-Control Studies; D005176:Factor XIII / Q000235:genetics*; D005260:Female; D005317:Fetal Growth Retardation / Q000235:genetics*; D006239:Haplotypes; D006801:Humans; D007231:Infant, Newborn; D016014:Linear Models; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics; D017395:Plasminogen Activator Inhibitor 1 / Q000235:genetics*; D011110:Polymorphism, Genetic; D019851:Thrombophilia / Q000235:genetics*
chemical_list: D017395:Plasminogen Activator Inhibitor 1; D005176:Factor XIII; D042965:Methylenetetrahydrofolate Reductase (NADPH2)