Obesity and cell-free DNA “no calls”: is there an optimal gestational age at time of sampling?

Livergood, Mary Christine; LeChien, Kay A.; Trudell, Amanda

doi:10.1016/j.ajog.2017.01.011

Cited by 57 publications

(45 citation statements)

References 12 publications

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“…Only 0.4% of the total specimens received had TNPs for technical reasons, but other reasons for post-analytic TNPs include underlying biological factors (maternal fibroids, malignancy, fetal fraction), which can affect interpretation of cfDNA results. Reasons for low fetal fraction include fetal aneuploidy (Hui, 2016;Pergament et al, 2014) and high maternal body mass index (Hui, 2016;Livergood, LeChien, & Trudell, 2017); novel research has also found that maternal anticoagulant usage contributes to low fetal fraction levels (Grömminger et al, 2015;Hui, 2016;Wardrop et al, 2016). Another underlying biological factor may be maternal fibroids and malignancy, which have been associated with uninformative DNA patterns (Bianchi, Chudova et al, 2015).…”

Section: Discussionmentioning

confidence: 99%

Prenatal cell‐free DNA screening for fetal aneuploidy in pregnant women at average or high risk: Results from a large US clinical laboratory

Guy

Haji‐Sheikhi

Rowland

et al. 2019

Molec Gen & Gen Med

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Background We evaluated the performance of a cell‐free DNA (cfDNA) prenatal screening assay for trisomies 21, 18, and 13, and sex chromosome aneuploidies (SCAs) among a population of pregnant women that included both those at average and high risk. Methods Specimen collection, cfDNA extraction, massively parallel sequencing, and bioinformatics analysis were conducted per laboratory protocol. Assay results, concordance with pregnancy outcomes, and performance characteristics were evaluated. Results A total 75,658 specimens from 72,176 individual pregnant women were received. Technical reasons accounted for 288 (0.4% of all received samples) tests not performed. In the final analysis cohort ( N = 69,794), 13% of pregnancies were considered at average risk and 87% at high risk. Mean gestational age at specimen collection was 15.1 weeks. Of the 69,794 unique pregnancies, 1,359 (1.9%) had positive test results. Among the results with confirmed outcomes, PPV for trisomies 21, 18, and 13 was 98.1%, 88.2%, and 59.3%, respectively; the PPV was 69.0% for SCAs and 75.0% for microdeletions. Overall, PPV was 87.2%, sensitivity was 97.9%, and specificity was 99.9%. Conclusion This cfDNA prenatal screening assay provides highly accurate discrimination between affected and unaffected pregnancies among a population of pregnant women at average and high risk for fetal genetic abnormalities.

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Section: Discussionmentioning

confidence: 99%

Prenatal cell‐free DNA screening for fetal aneuploidy in pregnant women at average or high risk: Results from a large US clinical laboratory

Guy

Haji‐Sheikhi

Rowland

et al. 2019

Molec Gen & Gen Med

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“…Several factors including gestational age, fetal karyotype and maternal obesity affect FF. Multiple studies have found an association between increasing maternal weight and decreasing FF 4‐14 . The comparatively lower FF in obese women may be explained by a greater cell turnover, apoptosis of adipose tissue or a dilutional effect due to an increased maternal blood volume 15 …”

Section: Introductionmentioning

confidence: 99%

Noninvasive prenatal testing and maternal obesity: A review

Juul

Hartwig

Ambye

et al. 2020

Acta Obstet Gynecol Scand

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Abbreviations: BMI, body mass index; FF, fetal fraction; NIPT, noninvasive prenatal test. AbstractNoninvasive prenatal testing (NIPT) has become a popular screening test for the most common fetal aneuploidies. The performance of NIPT is affected by several factors including maternal obesity, which results in a greater rate of no-calls for obese pregnant women. Guidelines regarding NIPT in prenatal screening have been published, but with few and divergent recommendations on the issue. We aimed to review the medical literature, guidelines from scientific societies and information material from commercial NIPT providers on no-calls and maternal obesity. We systematically identified medical literature and guidelines from scientific societies using the database MEDLINE.Information material from commercial NIPT providers was found via a systematic search on Google.com. Nine medical studies investigating the association between maternal obesity and NIPT no-calls were included. They all showed the same trend: increasing no-call rate with increasing maternal obesity. The no-call rate ranged from 0% to 4.2% for women with body mass index (BMI) 18.5-24.9 and from 5.4% to 70.1% for women BMI ≥40. We identified 17 scientific societies with guidelines and 13 commercial NIPT providers. All were checked for information material on no-calls and maternal obesity. To allow comparison, all guidelines were examined to answer the same three predefined questions. Of the 17 included scientific societies, 13 (76.5%) mentioned the association between maternal obesity and NIPT no-calls, two (11.8%) specified weight limits and three (17.6%) advised against NIPT for severely obese pregnant women.None of the 13 commercial NIPT providers provided specific recommendations, but four (30.8%) cite maternal obesity as a potential cause for a no-call. Because of the increasing number of patients in this group, we advocate updated recommendations to guide decision making in prenatal screening for obese pregnant women. K E Y W O R D Sfetal aneuploidy, guideline, maternal obesity, NIPT, no-call, noninvasive prenatal test

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“…A 'no-result' report is generated when the NIPT algorithm cannot make a high-confidence call, usually because the FF is too low. FF increases with gestational age (GA) 5,6 , but decreases with increasing maternal weight (MW) [7][8][9] . FF is lower in cases of trisomy 13, trisomy 18 and digynic (maternal) triploidy (all of which tend to have smaller placentas) 8,[10][11][12][13][14] .…”

Section: Introductionmentioning

confidence: 99%

Fetal fraction‐based risk algorithm for non‐invasive prenatal testing: screening for trisomies 13 and 18 and triploidy in women with low cell‐free fetal DNA

McKanna

Ryan

Krinshpun

et al. 2018

Ultrasound in Obstet & Gyne

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For pregnancies with a FF too low to receive a result on standard NIPT, the FFBR algorithm identified a subset of cases at increased risk for trisomy 13, trisomy 18 or triploidy. For the remainder of cases, the risk of a fetal chromosomal abnormality was unchanged from that expected based on MA and GA. © 2018 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

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Obesity and cell-free DNA “no calls”: is there an optimal gestational age at time of sampling?

Cited by 57 publications

References 12 publications

Prenatal cell‐free DNA screening for fetal aneuploidy in pregnant women at average or high risk: Results from a large US clinical laboratory

Prenatal cell‐free DNA screening for fetal aneuploidy in pregnant women at average or high risk: Results from a large US clinical laboratory

Noninvasive prenatal testing and maternal obesity: A review

Fetal fraction‐based risk algorithm for non‐invasive prenatal testing: screening for trisomies 13 and 18 and triploidy in women with low cell‐free fetal DNA

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