Adverse perinatal outcomes are more frequent in pregnancies with a low fetal fraction result on noninvasive prenatal testing

Abstract

Objective This study aimed to assess risk of an adverse perinatal outcome for women with a low fetal fraction (LFF) result on noninvasive prenatal testing (NIPT).Study Design A retrospective cohort study whereby women with an LFF result were compared with women who had a sufficient fetal fraction (SFF) result on NIPT. Inclusion criteria were singleton pregnancies with quantification of fetal fraction and pregnancy outcome information. Primary outcome was a composite of any of the following: miscarriage, fetal demise, neonatal death, preterm birth, pregnancy-associated hypertensive disorder, placental abruption, and low birth weight.Results Three hundred forty-eight (94%) women had an SFF result, and 22 (6%) women had an LFF result. The mean gestational age at the time of NIPT was comparable for both groups. Women with an LFF result were more likely to be African American (86% vs 52%; p = 0.007) and have a higher body mass index (BMI) (mean BMI = 37 kg/m 2 vs BMI = 29 kg/m 2 ; p ≤ 0.001) than women with an SFF result. The composite outcome was significantly more common in the LFF group (59.1% vs 29%; p = 0.003). After adjusting for race and BMI, LFF remained independently associated with adverse perinatal outcome with adjusted odds ratio = 2.5 (95% confidence interval 1.01-6.2; p = 0.049).Conclusions Women with an LFF result have an increased likelihood of an adverse pregnancy outcome.

Open source non‐invasive prenatal testing platform and its performance in a public health laboratory

“…Because we observed 3/11 samples in the validation set that were excluded because of insufficient fetal DNA fraction to be abnormal (two trisomy 18 and one triploidy), we suggest paying extra attention to pregnancies revealing low SeqFF result. This observation is supported by a recent publication . We performed a simple yet powerful analysis for the determination of fetal sex.…”

“…This observation is supported by a recent publication. 24 We performed a simple yet powerful analysis for the determination of fetal sex. The model correctly predicted the fetal sex of 172/173 samples of the validation set and gave an incorrect result for one triploid fetus (69,XXY).…”

Repeated failed non-invasive prenatal testing in a woman with immune thrombocytopenia and antiphospholipid syndrome: lessons learnt

“…In contrast, there was no significant difference in fetal cfDNA levels in women who developed pre-eclampsia and women who did not develop pre-eclampsia in a recent nested case–control study 14. A retrospective cohort study on 348 women undergoing NIPT found a low fetal fraction in 22 (6%) women and an association between low fetal fraction and adverse perinatal outcome with an adjusted OR of 2.5 15. In the study, patients with low fetal fraction were more likely to have pregnancy-associated hypertensive disorders, including pre-eclampsia (59.1% compared to 26.4%, p=0.001).…”

“…In the study, patients with low fetal fraction were more likely to have pregnancy-associated hypertensive disorders, including pre-eclampsia (59.1% compared to 26.4%, p=0.001). Other significant adverse perinatal outcomes included preterm birth <37 weeks of gestation 15. There was no mention if patients with poor outcomes had associated autoimmune disorders or comorbidities.…”

Noninvasive Prenatal Testing - When Is It Advantageous to Apply

“…Here the test is repeated to exclude technical problems with another 10- to 14-day delay in decision making. If the test is still not feasible, the pregnancy is actually at higher risk for an adverse outcome [61] and subsequent pregnancy control is recommended. …”