title: Longitudinal evaluation of activated protein C resistance among normal pregnancies of Hispanic women.
abstract: OBJECTIVE
  This study was undertaken to describe pregnancy-associated activated protein C resistance and the presence of the factor V Leiden mutation in a sample population of pregnant Hispanic women.
  
  
  METHODS
  Twenty healthy Hispanic women with single intrauterine pregnancies were randomly selected. Blood samples were taken before 8 weeks' gestation, every 4 weeks during pregnancy, and at 6 weeks post partum. Samples were collected, separated, and stored at -70 degrees C until assay. Standard and modified partial thromboplastin time-based assays were used to evaluate response to activated protein C. A sensitivity ratio < or =2 indicated resistance to activated protein C. Repeated measures analysis of variance and unpaired t tests were used as appropriate. P <.05 was considered significant.
  
  
  RESULTS
  Mean (+/-SEM) maternal age was 29 +/- 5 years, and most women were multiparous. Mean gestational age at delivery was 38 weeks' gestation, and the mean birth weight was 3000 g. According to the standard assay, 10 women (50%) acquired activated protein C resistance by 13 weeks' gestation, and this condition persisted through delivery and resolved post partum. Another two had preexisting activated protein C resistance. Results of the standard assay were significantly different for women with preexisting and pregnancy-associated activated protein C resistance (1.55 vs 2.18; P =.01). The modified assay distinguished between women with preexisting and pregnancy-associated activated protein C resistance at 8 weeks' gestation, 24 weeks' gestation, and post partum. The pregnancies of the women with preexisting activated protein C resistance were complicated by oligohydramnios at 34 weeks' gestation and required delivery at 36 weeks' gestation. One infant was small for gestational age. Allele-specific polymerase chain reaction analysis demonstrated that both patients with preexisting activated protein C resistance carried one copy of the factor V Leiden mutation.
  
  
  CONCLUSIONS
  The incidences of pregnancy-associated and factor V Leiden mutation-associated activated protein C resistances in our cohort of gravid Hispanic women was higher than previously reported. Factor V Leiden-associated activated protein C resistance in two patients was associated with adverse perinatal outcome.
authors.affiliation: Department of Obstetrics and Gynecology, University of Southern California School of Medicine, Los Angeles, CA, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Fassett
authors.forename: Y C
authors.initials: YC
authors.lastname: Bohn
authors.forename: J
authors.initials: J
authors.lastname: Kuo
authors.forename: D A
authors.initials: DA
authors.lastname: Wing
mesh_terms: D000328:Adult; D000483:Alleles; D015331:Cohort Studies; D004351:Drug Resistance / Q000235:genetics; D005165:Factor V / Q000235:genetics; D005260:Female; D005838:Genotype; D006630:Hispanic or Latino; D006801:Humans; D008137:Longitudinal Studies; D009154:Mutation / Q000235:genetics / Q000502:physiology; D010641:Phenotype; D016133:Polymerase Chain Reaction; D011247:Pregnancy / Q000208:ethnology* / Q000502:physiology*; D011248:Pregnancy Complications / Q000503:physiopathology; D011256:Pregnancy Outcome; D011486:Protein C / Q000502:physiology*; D012016:Reference Values
chemical_list: D011486:Protein C; C095381:factor V Leiden; D005165:Factor V