Procedure

Chorionic Villus Sampling

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Chorionic Villus Sampling

  • See Also
  1. Antenatal Screening
  • Definition
  1. Definitive, first trimester Antenatal Screening for fetal chromosomal abnormalities
  • Indications
  1. Antenatal Screening for fetal chromosomal abnormalities for high risk pregnancies
  • Protocol
  1. Performed between 10-13 weeks gestation
  2. Placental tissue sampling techniques
    1. Transabdominal sampling
    2. Transcervical sampling
      1. Higher Incidence of pregnancy loss than with abdominal sampling
      2. Indicated if placenta posterior or bowel blocks abdominal sampling
  • Adverse Effects
  1. Pregnancy loss
    1. Risk: 0.6 to 4.6% (higher rate than with Amniocentesis)
  2. Limb reduction defects
    1. Gestational age 10-13 weeks: Risk does not exceed general population risk (6 per 10,000)
    2. Gestational age <10 weeks: 1-2% risk of limb reduction defect
  1. Test Sensitivity: 97.8%
  2. Test Specificity: 98-99%
  • References
  1. Anderson (2009) Am Fam Physician 79(2): 117-24 [PubMed]
  2. Caughey (2006) Obstet Gynecol 108: 612-6 [PubMed]