Hyperechogenic fetal bowel and elevated serum alpha-fetoprotein: a poor fetal prognosis

To evaluate the clinical significance of increased fetal bowel echogenicity in women with elevated maternal serum alpha-fetoprotein (MSAFP) during the second trimester.

The study group comprised six pregnant women with elevated second-trimester MSAFP (greater than 2.5 multiples of the median), whose ultrasonographic evaluations indicated hyperechogenic fetal bowel. They were compared with six pregnant women whose fetuses, during routine second-trimester ultrasonographic screening for fetal anomalies, were found to have a hyperechogenic bowel without elevated MSAFP, according to natural history, pregnancy outcome, and associated features.

All six fetuses with the combination of elevated MSAFP and echogenic bowel were growth-restricted; four died in utero and one of the two live-born infants died during the neonatal period. The single survivor in this group was born prematurely; necrotizing enterocolitis was diagnosed at 30 days of life and surgery was performed. None of the cases had associated congenital anomalies. Only one of the six controls had associated anomalies (trisomy 21), and this pregnancy was terminated. The pregnancy course of the remaining five fetuses was normal; all were appropriate for gestational age and were delivered at term. No perinatal mortality occurred in this group; however, in one infant, cerebral palsy was diagnosed at 10 months of age.

Fetal bowel hyperechogenicity found in women with elevated second-trimester MSAFP levels is associated with poor fetal outcome, particularly fetal growth restriction with fetal and neonatal death, and should be considered an ominous prenatal finding.