AMNIOTIC-FLUID ALPHA-FETOPROTEIN DETERMINATION AT THE TIME OF GENETICAMNIOCENTESIS - HAS IT OUTLIVED ITS USEFULNESS

The purpose of this retrospective study was to evaluate the utility of routine measurement of amniotic fluid alpha-fetoprotein levels at the time of second trimester genetic amniocentesis (mean gestational age, 17.3 weeks +/- 2.5 weeks standard deviation; median, 16.8 weeks; rang e, 15 to 22 weeks). During the study period 7174 patients underwent se cond trimester genetic amniocentesis. Outcome data were available in a ll cases. In 79 (1.1%) cases the amniotic fluid alpha-fetoprotein leve l was greater than or equal to 2.0 multiples of the median. Thirty-thr ee of the 79 (42%) patients had normal ultrasonograms, and in 31 of 33 (94%) the amniotic fluid alpha-fetoprotein level was between 2.0 and 3.0 multiples of the median. Forty-six of the 79 (58%) patients had ab normal ultrasonographic findings, and of these, 82% were neural tube d efects, abdominal wall defects, or cystic hygromas. Acetylcholinestera se was positive in 37 cases, all of which had abnormal ultrasonographi c findings. None of the fetuses with negative findings on sonographic screening had detectable abnormalities at birth. In this study, with o ver 7000 patients, amniotic fluid alpha-fetoprotein and acetylcholines terase levels did not increase the detection of fetal abnormalities. O n the basis of these results, routine measurement of amniotic fluid al pha-fetoprotein level at the time of routine genetic amniocentesis (15 to 22 weeks) does not appear justified.