title: Stage II ultrasound examination for the diagnosis of fetal abnormalities with an elevated amniotic fluid alpha-fetoprotein concentration.
abstract: Previous studies have indicated that patients with elevated levels of amniotic fluid alpha-fetoprotein (AFAFP) are at very high risk for fetal neural tube defects. Twenty-eight patients whose levels of AFAFP were greater than 3 standard deviations above the mean were evaluated with a Stage II ultrasound examination for detailed assessment of fetal anatomy. In 16 patients with AFAFP levels greater than 5 SD above the mean, six fetuses with open spina bifida were identified (37.5%). Moreover, in four fetuses in this group, the diagnosis was ventral wall defects (two with gastroschisis and two with omphalocele), and one fetus had multiple lethal anomalies. The other 5 patients had normal scans, and, with the exception of one patient who was delivered of a nondysmorphic stillborn infant at 28 weeks, all had normal infants at birth. Among the other 12 patients with AFAFP levels between 3 and 5 SD above the mean, there were only two adverse findings--an intrauterine death and an omphalocele. A Stage II ultrasound examination performed when AFAFP levels are elevated enables one to distinguish between conditions which are lethal or associated with significant impairment and those which are amenable to surgical procedures. Morphologically normal fetuses can also be identified. Since this diagnostic technique will allow salvage of many pregnancies that otherwise would be aborted, it should be an integral part of any alpha-fetoprotein screening program.
mesh_terms: D000009:Abdominal Muscles / Q000002:abnormalities; D000015:Abnormalities, Multiple / Q000175:diagnosis; D000653:Amniotic Fluid / Q000032:analysis*; D000013:Congenital Abnormalities / Q000175:diagnosis*; D003937:Diagnosis, Differential; D005260:Female; D005313:Fetal Death / Q000175:diagnosis; D006554:Hernia, Umbilical / Q000175:diagnosis; D006801:Humans; D009436:Neural Tube Defects / Q000175:diagnosis; D011247:Pregnancy; D011296:Prenatal Diagnosis; D016136:Spina Bifida Occulta / Q000175:diagnosis; D014463:Ultrasonography; D000509:alpha-Fetoproteins / Q000032:analysis*
chemical_list: D000509:alpha-Fetoproteins