FAINT AND POSITIVE AMNIOTIC-FLUID ACETYLCHOLINESTERASE WITH A NORMAL SONOGRAM

OBJECTIVE: Both faint and positive amniotic fluid acelylcholinesterase determinations have been associated with fetal abnormalities. We eval uated the effect of a normal sonogram and positive or faint acetylchol inesterase level on the risk for anomalies. STUDY DESIGN: Between Jan. 1, 1989, and Feb. 1, 1995, 4859 amniocenteses were performed. Twenty- three cases of abnormal acetylcholinesterase determinations combined w ith normal sonograms were identified and pregnancy outcomes were deter mined. RESULTS: One abnormal karyotype was identified (45,X/47,XXX mos aic). No neural tube defects were seen in infants with an abnormal ace tylcholinesterase determination and normal sonogram. One fetus of a tw in pregnancy had a ventral wall defect that was not detected on ultras onography. Seventy-three percent of infants were normal at birth, but 27% of the pregnancies had abnormal outcomes. CONCLUSIONS: Advances in ultrasonography have led to improved detection of fetal abnormalities . With a normal karyotype, repeat invasive testing may not be necessar y.