Comparison of Amniotic-Fluid and Maternal Serum Alpha-Fetoprotein Levels in the Early Antenatal Diagnosis of Spina Bifida and Anencephaly

α-Fetoprotein and the Prenatal Diagnosis of Central Nervous System Disorders

“…3). The incomplete success of maternal serum AFP screening shown in figure 3 has been confirmed in other smaller studies [48,77,94], It raises several problems. Though it is probable that technical improvements in the assay will reduce the number of CNS malformations missed, it re mains very likely that a substantial proportion of cases will not be asso ciated with raised maternal serum AFP at any stage of gestation.…”

“…The potential of this new approach was initially disputed [48], However, further data showed that maternal serum AFP determination would iden tify some, though by no means all, cases of both anencephaly and spina bifida [26,29,56,77,95]. It will be some time before the efficacy of the new method can be pre cisely defined.…”

Biochemical Tests for the Assessment of Feto-Placental Function

“…Seller et al, (1974) did not obtain good discrimination between affected and normal pregnancies using this method, and they concluded that serum levels were less reliable than amniotic fluid assays. Harris et al, (1974) obtained normal results in eight out of nine affected pregnancies, and suggested that high maternal serumalpha-fetoprotein levels were more likely to be due to feto-placental dysfunction than to neural tube malformations per se.…”

“…At best it seems likely that only the more severely affected 'open' malformations will be detected (Harris et al, 1974) and other causes of high levels such as multiple pregnancies and nonneurological fetal abnormalities will have to be considered. Some of the present disagreement, however, may arise from differing reference ranges, varying times of blood sampling, and failure to classify the severity of the neural tube lesion.…”

Alphafetoprotein and neural tube defects

“…However, an exception must be made of those disorders where the lesion is closed, ie, covered by a full thickness of skin. An occipital encephalocele (Harris et al, 1974), a case of iniencephaly (Nevin et al, 1974) and several examples of closed meningocelespinabifidas (Stewart et al, 1975;Vince et al, 1975) have been reported. Uncomplicated hydrocephaly probably also belongs in this group, though so far only cases from late in pregnancy have been described (Brock and Sutcliffe, 1972;Seppala and Unnerus, 1974).…”