Table 2 Maternal pregnancy and prenatal testing characteristics (N = 160).

From: Utility of noninvasive genome-wide screening: a prospective cohort of obstetric patients undergoing diagnostic testing

 

Mean (SD) or N (%), range

Gestational age at sample collection (weeks)

18.2 (8.1), 10.9–40.6

Fetal fraction (%)

10.4 (4.9), 2.0–27.0

Normal fetal anatomic survey (N = 126)

  No

69 (54.8%)

  Yes

57 (45.2%)

Type of diagnostic testing

  Amniocentesis

74 (46.3%)

  Chorionic villus sampling

68 (42.5%)

  Cord blood

17 (10.5%)

  Percutaneous umbilical blood sampling (PUBS)

1 (0.6%)

Documented indication for diagnostic testinga

  Fetal anomaly suspected on ultrasound

69 (43.1%)

  Parents known to be carriers of genetic disorder

19 (11.9%)

  Increased nuchal translucency

29 (18.1%)

  Positive aneuploidy screen

23 (14.4%)

  Advanced maternal age

17 (10.6%)

  Otherb

11 (6.9%)

  Previous pregnancy with a chromosomal disorder

9 (5.6%)

  Family history of inherited disorder

9 (5.6%)

Diagnostic testing orderedc

  Chromosomal microarray

131 (81.9%)

  Karyotype

64 (40.0%)

  Otherd

21 (13.1%)

  Single-gene or gene panel

16 (10.0%)

Pregnancy outcome

  Live birth

99 (61.9%)

  Termination

42 (26.3%)

  Unknown

9 (5.6%)

  Miscarriage

6 (3.8%)

  Stillbirth

4 (2.5%)

  1. aProviders consenting for diagnostic testing documented one or more indications for diagnostic testing; they were not mutually exclusive. Thus, the sum of all categories is greater than 100%.
  2. bOther indications for diagnostic testing included isoimmunization (3), concern for chorioamnionitis (3), concern for CMV infection (3), known maternal Robertsonian 13,14 translocation (1), and fetal sex discordance between preimplantation genetic testing for aneuploidies (PGT-A) and noninvasive prenatal screening (NIPS). PGT-A is a technology that tests a few cells of a developing embryo for aneuploidy prior to transfer during in vitro fertilization.
  3. cTypes of diagnostic testing ordered were not mutually exclusive. Thus, the sum of all categories is greater than 100%.
  4. dOther testing ordered included: 7-dehydrocholesterol, TORCH titers, blood typing, uniparental disomy (UPD) studies, FMR1 testing, spinal muscular atrophy (SMA) testing, and methylation testing.
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