Prenatal Diagnosis – Genetic Testing Indications

Indications For Karyotype Analysis

Prenatal Diagnosis: Cytogenetic testing of the fetus is considered routine prenatal care in following pregnancies:

  • Advanced maternal age
  • Abnormal maternal serum screening test
  • Abnormal ultrasound findings
  • Miscarriage, stillbirths and perinatal deaths
  • Individuals with infertility or recurrent miscarriages
  • Anomalies of sexual development
  • Family history of a known or suspected chromosome abnormality

Other Indication: Cytogenetic testing is also indicated to complement the results of chromosome microarray array analysis (CMA). Standard cytogenetic testing is required to detect balanced chromosome abnormalities which are not detected by CMA and sometimes it is required to clarify the mechanisms of genomic changes detected by the CMA.

Indications For Fluorescence In Situ Hybridization

  • Rapid detection (result available within 24 hours) of chromosome aneuploidy for prenatal diagnosis
  • Suspected microdeletion or microduplication syndrome
  • Clarification of copy number changes detected by chromosome microarray analysis and certain structural chromosome abnormalities with terminal rearrangements detected by karyotype analysis.
  • Suspected aneuploidy or mosaicism for aneuploidy

Indications for Chromosomal Microarray Analysis

  • Abnormal maternal serum screen
  • Abnormal Ultrasound findings
  • Still birth or History of Miscarriage
  • Family history of a genetic disease detected by CMA

The American College of Obstetricians and Gynecologists (The College) and the Society for Maternal-Fetal Medicine (SMFM) have recommended Chromosomal Microarray Analysis (CMA) as the first-line genetic test in pregnancies showing fetal abnormalities in an ultrasound scan. (Read more)