Fetal fraction of cell free DNA in screening for hypertensive disorders at 11–13 weeks

Abstract

Objective

To investigate whether first-trimester maternal plasma fetal fraction is altered in women that subsequently develop preeclampsia (PE) or gestational hypertension (GH) and to examine its potential value in improving the performance of screening for PE and GH by maternal factors and maternal serum pregnancy associated plasma protein-A (PAPP-A), mean arterial pressure (MAP) and uterine artery pulsatility index (UtA-PI).

Methods

The study population of 10,131 pregnancies undergoing cell free fetal DNA testing at 11–13 weeks’ gestation included 91 (0.9%) cases with preterm-PE, 222 (2.2%) cases with term-PE, 360 (3.6%) with GH and 9,458 (93.4%) cases unaffected by hypertensive disorders. Maternal plasma fetal fraction levels were expressed as multiples of the median (MoM) after adjustment for maternal factors and crown-rump length. The performance of screening for preterm-PE, term PE and GH by maternal factors and MoM values of fetal fraction, PAPP-A, UtA-PI and MAP was evaluated by receiver operating characteristic (ROC) curves.

Results

The median fetal fraction MoM was significantly lower in the preterm-PE (0.825; IQR 0.689–1.115 MoM, p < .001), term-PE (0.946; IQR 0.728–1.211 MoM, p = .028) and GH (0.928; IQR 0.711–1.182 MoM, p < .001) groups than in the unaffected group (1.002; IQR 0.785–1.251 MoM). However, the performance of screening for PE or GH by maternal factors alone or by maternal factors and PAPP-A, UtA-PI and MAP was not significantly improved by the addition of fetal fraction.

Conclusions

First trimester maternal plasma fetal fraction is not useful in screening for hypertensive disorders of pregnancy.

Keywords:

• Fetal fraction
• cell free DNA
• preeclampsia
• hypertensive disorders
• first trimester

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study was supported by grants from the Fetal Medicine Foundation [UK Charity No: 1037116)]. The cost of collection and analysis of the samples for the cfDNA test was covered by Roche/Ariosa Diagnostics, Inc., San Jose, CA, USA. These bodies had no involvement in the study design; in the collection, analysis and interpretation of data; in the writing of the report; and in the decision to submit the article for publication.