Biochemical analysis of cystic fluid in the diagnosis of fetal intra‐abdominal masses

ABSTRACT Objective

The aim of the study was to evaluate a biochemical analysis of fluid sampled in utero from fetal abdominal cystic masses.

A retrospective study of 42 intra‐abdominal cystic masses [ovarian cysts (n = 22), cloaca (n = 8), urodigestive fistulae (n = 4), and urogenital sinuses (n = 8)] was carried out. The control group (n = 30) consisted of fetal urine. Seven biochemical markers were assayed: sodium, estradiol, β₂‐microglobulin, total proteins and digestive enzymes, gamma‐glutamyl transpeptidase, aminopeptidase M, and intestinal alkaline phosphatase isoenzyme. Outcome of pregnancies and final diagnosis of intra‐abdominal mass were known in all cases.

Biochemical patterns allowed to demonstrate (1) an ovarian origin based on elevated level of estradiol and of total proteins (100% specificity, 100% sensitivity); (2) urodigestive fistula based on the presence of high levels of digestive enzymes (cloaca in female fetuses or recto‐urethral fistula in male fetuses); and (3) a renal origin (urinary pattern with low total proteins and absence of digestive enzymes); however, a biochemical pattern could not differentiate between fetal urogenital sinus and megacystis.

Etiological diagnosis of a fetal cystic abdominal mass could impact both prenatal and postnatal management providing adapted prenatal counseling by a pediatric surgeon in surgically correctable congenital anomalies. © 2012 John Wiley & Sons, Ltd.