Provide proactive care sooner with the Prequel Prenatal Screen

The American College of Obstetricians and Gynecologists (ACOG) recommends using early insights from prenatal genetic screens to potentially improve outcomes.^1,2,3 Prequel is a cell-free DNA (cfDNA) screen that can provide reliable insights about your patients’ babies as early as eight weeks’ gestation. In the rare event a pregnancy is at an increased risk for a chromosomal condition, these results give your patients more time and information to plan and prepare.⁴

Only Prequel uses AMPLIFY™ Technology

AMPLIFY Technology makes Prequel the only prenatal cfDNA screen that delivers results that are 99.9% accurate for patients—on the first draw.⁵ By enriching fetal fraction, the Prequel Prenatal Screen improves sample performance for patients of all BMIs.^6,7

Learn more about fetal fraction

How fetal fraction affects patient results

50%

of pregnant patients present with high BMIs, which can lead to low fetal fraction^8,9

24.3%

of patients have inconclusive results due to low fetal fraction⁶

How AMPLIFY enhances results

3.9x

increase in previously low fetal fraction samples⁵

2.3x

average increase in fetal fraction⁵

Reduce inconclusive results with fetal fraction amplification

Move the slider from right to left to see how the Prequel Prenatal Screen with AMPLIFY enhances fetal fraction regardless of BMI. In particular, fetal fraction amplification helped patients who originally had less than 4% fetal fraction receive results with Prequel when they would have been at higher risk of inconclusive results with other screens.^4,9

Learn how AMPLIFY delivers results sooner

$Interactive infographic comparing before-and-after data of pregnant individuals with initially low fetal fraction versus those with sufficient fetal fraction, showing changes in key data points.$ $Interactive infographic comparing before-and-after data of pregnant individuals with initially low fetal fraction versus those with sufficient fetal fraction, showing changes in key data points.$

= Pregnant people with initially low fetal fraction

= Pregnant people with fetal fraction above 4%

Screen for genetic risks sooner

The Prequel Prenatal Screen is the only cfDNA screen available at eight weeks’ gestation. In the rare event a baby is at risk of a genetic condition, the sooner your patients know, the more time they will have to pursue diagnostic testing and consult with specialists.⁴

Myriad compared Prequel to traditional cfDNA screens to see how soon fetal fraction amplification can provide results.

Prequel with AMPLIFY can achieve higher fetal fractions at eight weeks when compared to other screens at 10 weeks.⁴

Identify pregnancies at increased risk of complications

Provide more comprehensive care to your patients during pregnancy with Expanded Aneuploidy Analysis. It can help you assess if their pregnancies are at a higher risk for complications such as preterm birth, in addition to screening for genetic conditions that may affect their baby.¹⁰

Find out more

1 in 200

Keep in mind… 1 in 200 pregnancies are at risk for a rare autosomal aneuploidy¹¹

Screen for aneuploidy risks early

Through Prequel with Expanded Aneuploidy Analysis, you can identify aneuploidy risk sooner. This allows you to modify your patient’s monitoring plan, if needed.^{10, 11}

Prequel screening options

Standard Panel Common Aneuploidies
- Trisomy 13 (Patau syndrome)
- Trisomy 18 (Edwards syndrome)
- Trisomy 21 (Down syndrome)
Available for singleton and twin pregnancy.
Sex Chromosome Analysis (Opt-in)
- Monosomy X (Turner syndrome)
- Klinefelter syndrome (XXY)
- Trisomy X (XXX)
- XYY syndrome
- Male (XY)
- Female (XX)
Available for singleton and twin pregnancy.
Microdeletions (Opt-in)
- 22q11.2 deletion (DiGeorge syndrome)
- 1p36 deletion syndrome
- 15q11.2 deletions (Angelman or Prader-Willi syndrome)
- 4p deletion (Wolf-Hirschhorn syndrome)
- 5p deletion (Cri-du-Chat syndrome)
Available for singleton pregnancy only.
Expanded Aneuploidy Analysis (Opt-in)
Expands aneuploidy analysis to include all 22 autosomes. Associated conditions include:
- Placental insufficiency (e.g. growth restriction, stillbirth)
- Uniparental disomy syndromes (e.g. Prader-Willi, Beckwith-Wiedemann)
- Fetal syndromes (e.g. trisomy 8, trisomy 22)
Available for singleton pregnancy only.

Trust in high positive predictive values

Prenatal diagnosis of 22q11.2 deletion syndrome (22q11.2 DS), also known as DiGeorge syndrome, can improve both pregnancy management and outcomes for newborns. The American College of Medical Genetics and Genomics (ACMG) recommended offering cfDNA screening for it, which had not been supported previously due to low positive predictive values. A recent study showed how the Prequel Prenatal Screen amplified fetal fraction, resulting in one of the industry’s highest reported positive predictive values for 22q11.2 DS.¹² A positive result from the Prequel Prenatal Screen should be followed up with prenatal diagnosis.

Read the study

Learn how Prequel provided up to 100% positive predictive values for 22q microdeletion detection

How enhanced screening technology benefits you

In addition to AMPLIFY Technology, the Prequel Prenatal Screen uses Whole genome sequencing (WGS). WGS has a higher sensitivity than Single nucleotide polymorphism (SNP), which is another form of cfDNA screening.^7,13

Compared to SNP, WGS leads to lower sample failure rates. This gives it the potential to reduce your staff’s workload through:

Fewer calls from anxious patients
Fewer redraws
Fewer invasive diagnostic procedures¹⁵

Watch a video about SNP vs WGS

Real-world performance (clinical experience)

Metric	SNP	WGS
Overall sensitivity (common trisomies)	95.5%¹³	98.6%⁷
Affected pregnancies with inconclusive results	7.5%¹³	0%⁷
Failure rate	2.55%^*14	0.1%⁷

*Due to low fetal fraction only (excludes QC failures)

Who is the Prequel Prenatal Screen for?

See the types of patients who would be a good fit for the Prequel Prenatal Screen.

NOE

No significant risk

Seeks baby’s predicted sex
1 in 200 chance of aneuploidy, despite absence of significant risk factors¹¹

MARIA

Sample failure risk

Presents with high BMI
At risk of low fetal fraction at eight weeks

CALLIE

High risk

A high-risk pregnancy due to:

Age or prior pregnancies
Family history

Become a SneakPeek® clinical provider

Over 99% accuracy as early as six weeks¹⁶

Empower your patients to find out the sex of their baby as early as six weeks into pregnancy.¹⁷

Learn more

Get in touch with Myriad Genetics

Speak with a representative to learn about our genetic testing portfolio.

Connect with us

References:

Dungan JS, et al. Noninvasive prenatal screening (NIPS) for fetal chromosome abnormalities in a general-risk population: An evidence-based clinical guideline of the American College of Medical Genetics and Genomics (ACMG). Genetics in Medicine. 2023;25(2):100336. doi:10.1016/j. gim.2022.11.004.
Screening for fetal chromosomal abnormalities. Obstetrics & Gynecology. 2020;136(4). doi:10.1097/aog.0000000000004084.
Committee Opinion No. 690 Summary: Carrier Screening in the Age of Genomic Medicine. 2017. Obstetrics & Gynecology. 129 (3): 595–96.
Dugoff L. Fetal fraction amplification enables accurate prenatal cell-free DNA screening at 8 weeks gestation. Presented at: the Society for Maternal Fetal Medicine 2025 Pregnancy Meeting; January 30, 2025; Denver, CO.
Welker NC, et al. High-throughput fetal fraction amplification increases analytical performance of noninvasive prenatal screening. Genetics in Medicine. 2021;23(3):443-450. doi:10.1038/s41436-020-01009-5.
Yared E, et al. Obesity increases the risk of failure of noninvasive prenatal screening regardless of gestational age. Am J Obstet Gynecol. 2016;215(3):370.e1-370.e3706. doi:10.1016/j.ajog.2016.03.018.
Hancock S, et al. Clinical experience across the fetal-fraction spectrum of a non-invasive prenatal screening approach with low test-failure rate. Ultrasound Obstet Gynecol. 2020;56(3):422-430. doi:10.1002/uog.21904.
Deputy NP, et al. Prevalence and Trends in Prepregnancy Normal Weight - 48 States, New York City, and District of Columbia, 2011-2015. MMWR Morb Mortal Wkly Rep. 2018;66(51-52):1402-1407. Published 2018 Jan 5. doi:10.15585/mmwr.mm665152a3.
Muzzey D, et al. Noninvasive prenatal screening for patients with high body mass index: Evaluating the impact of a customized whole genome sequencing workflow on sensitivity and residual risk. Prenat Diagn. 2020;40(3):333-341. doi:10.1002/pd.5603.
Chawla D, et al. Screening Positive for Rare Autosomal Aneuploidies Increases Frequency of Adverse Pregnancy Outcomes and Alters Clinical Management. Prenat Diagn. 2025. doi/10.1002/pd.6776.
Toutain J, et al. Confined placental mosaicism revisited: Impact on pregnancy characteristics and outcome. PLoS One. 2018;13(4):e0195905. doi:10.1371journal/pone.0195905.
Hammer C, et al. High positive predictive value 22q11.2 microdeletion screening by prenatal cell-free DNA testing that incorporates fetal fraction amplification. Prenat Diagn. 2024; 44(8): 925-935. doi:10.1002/pd.6562.
Dar P, et al. Cell-free DNA screening for trisomies 21, 18, and 13 in pregnancies at low and high risk for aneuploidy with genetic confirmation. Am J Obstet Gynecol. 2022;227(2):259.e1-259.e14. doi:10.1016/j.ajog.2022.01.019.
Benn P, et al. Accuracy of fetal fraction measurements in a single-nucleotide polymorphism-based noninvasive prenatal test. Prenat Diagn. 2024;44(10):1218-1224. doi:10.1002/pd.6634
Artieri CG, et al. Noninvasive prenatal screening at low fetal fraction: comparing whole-genome sequencing and single-nucleotide polymorphism methods. Prenat Diagn. 2017;37(5):482-490. doi:10.1002/pd.5036.
See sneakpeek.com/publications for clinical studies
Milot H, et al. Large scale follow-up research study: SneakPeek® Early Gender DNA Test 99.9% accurate for fetal sex by live-birth confirmation. Int J Pregn & Chi Birth. 2020;6(6):165‒168. DOI: 10.15406/ipcb.2020.06.00217.