The purpose of this study is to establish the normal levels of α-fetoprotein in amniotic fluid between 15 and 22 weeks of gestation.

Amniotic fluid Alpha-fetoprotein(AFAFP)levels were measured by enzyme-immunoassy in pregnant women between 15 and 22 weeks of gestation for variety of indication of amniocentesis from October, 1994 to July, 1996 at Mokdong Hospital Ewha Womans University.

The study group was selected from normal karyotype at prenatal genetic diagnosis and no congenital anomaly of fetus.

The normal level of AFAFP was the highest at 16weeks and then it declined gradually as gestational weeks increased. The mean±SD levels of AFAFP from 15 to 22weeks were 16.9±5.7, 20.4±9.8, 13.8±6.8, 10.9±3.0, 8.1±2.3, 6.9±3.9, 5.6±1.6, 4.7±0.6µg/ml respectively, the median levels of AFAFP from 15 to 22weeks were 14.7, 16.2, 12.3, 11.0, 7.8, 5.5, 5.3, 4.8µg/ml, respectively.

We consider that this preliminary data normal AFAFP levels by each gestation weeks can be used as reference value for screening of anomalies or genetic disorder.