A part of second trimester or cross-trimester biochemical screening for Down syndrome and trisomy 18 syndrome
A marker of fetal demise
An adjunct biomarker in the prenatal diagnosis of disorders of fetal steroid metabolism, including Smith-Lemli-Opitz syndrome (SLO)(3-4), and X-linked ichthyosis (placental sulfatase deficiency disorders)
Evaluating primary or secondary fetal adrenal insufficiency after excluding other rare single gene defects, including aromatase deficiency, 17 alpha-hydroxylase deficiency and/or various forms of congenital adrenal hyperplasia
Like any immunoassay, this test can occasionally be subject to analytical interferences. Some patients who have been exposed to animal antigens, either in the environment or as part of treatment or imaging procedures, may have circulating anti-animal antibodies present. These antibodies may interfere with the assay reagents to produce unreliable results. If the clinical picture is inconsistent with the test results, clinicians should consider the possibility of a preanalytical or analytical error and contact the laboratory.
In second trimester maternal serum screening (QUAD), , unconjugated E3 (uE3) forms part of a complex, multivariate risk calculation formula, using maternal age, gestational stage, and other demographic information, in addition to the results of the biochemical markers, for Down syndrome and trisomy 18 risk calculation.
A serum uE3 <0.15 multiples of the gestational age median in women, who otherwise screen negative in the quad test, can indicate Smith-Lemli-Opitz syndrome and X-linked ichthyosis.
A low uE3 level can indicate the possibility of aromatase deficiency, congenital adrenal hyperplasia, primary or secondary (including maternal corticosteroid therapy) fetal adrenal insufficiency and/or fetal demise.