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Therapeutic abortions were performed in two cases of spina bifida which were diagnosed by determination of the lafa fetoprotein levels in the amniotic fluid and maternal serum.

Thirty-seven patients with a wide spectrum of spinal dysraphic lesions were studied by both magnetic resonance imaging (MRI) and myelography complemented by computed tomography (CT). Magnetic resonance imaging proved to be superior for tissue characterization, overall anatomical definition, topographical relationships of the cranio-cervical junction and demonstration of the presence and extent of hydrosyringomyelia. Demonstration by CT myelography of fine neural structures such as the filum terminale and nerve roots remains the superior technique; however, with constantly improving spatial resolution and thinner-slice imaging, MRI will become increasingly competitive in this respect. The osseous component of these lesions was best demonstrated by CT myelography. A high incidence of associated syrinx (8/15 cases) was found in the diastematomyelia group, with an overall incidence of 15 cases in all the dysraphic patients studied. The use of both T1- and T2-weighted sequences is required for tissue characterization. Whilst both imaging modalities proved complementary in the investigation of spinal dysraphism, we suggest that, with its superior tissue characterization and anatomical display of these lesions. MRI should be the primary imaging technique. Avoidance of an invasive procedure and use of ionizing radiation confers additional benefits upon MRI. The relative ease and shorter examination time of MRI makes this technique ideal for pre- and post-operative monitoring and assessment.

The chief obstetrical problems encountered today in the prenatal evaluation of the high-risk fetus are presented. Advantages and pitfalls or recent techniques utilized in the management of the high-risk pregnancy are discussed. They include: a prenatal scoring system for identifying the high-risk population; examination of the karyotype of cells in amniotic fluid, and quantitation of alpha-fetoprotein levels in maternal plasma and amniotic fluid for the early prenatal detection of birth defects; ultrasonography for the intrauterine diagnosis of fetal growth retardation and assessment of fetal maturity; the use of maternal urinary estriol excretion, maternal plasma human placental lactogen levels and the oxytocin stress test for the early detection of fetal distress; estimation of fetal maturity by amniotic fluid analysis of lecithin or lecithin-sphingomyelin ratios, creatinine and Blue Nile fetal cell staining. Newer, still experimental, techniques (e.g., fatal breathing movements, fetoscopy, and dehydroepiandrosterone plasma clearance) are viewed in light of further possible decreases in maternal and perinatal mortality.

In the newborn and foetus in the last months of gestation it is possible to see in lateral radiography of the spine, a longitudinal radiotransparent band which may divide the bone nucleus of the vertebral body into two portions. This front vertebral separation should be considered an expression of a reversible abnormality rather than a malformation to the extent that it almost always concerns a differentiation delay in the vertebral structures. The literature and personal cases show, in fact, that the finding disappears more or less rapidly.

A total of 5539 consecutive pregnant patients at three maternity units in the City and Hackney District of London were screened for fetal neural tube defect by measurement of maternal plasma alpha-fetoprotein (AFP) levels. Only 25-7% of women booked at 16 to 22 weeks, the optimum time for this screening test; 54-1% booked before 16 weeks and 20-2% after 22 weeks. Of the women tested before 23 weeks, 300 had elevated levels of AFP in plasma and 14 of them had fetuses with abnormalities known to cause a rise in AFP levels (12 fetuses had a neural tube defect and 2 had alimentary tract abnormalities). Of women examined before 23 weeks, half of those with twin pregnancies had elevated levels of plasma AFP as did 16-7% of those who ultimately had a spontaneous abortion.

Alpha2-macroglobulin (AMG) concentrations have been measured in amniotic fluids from 33 pregnancies where the outcome was an infant with a neural tube defect. AMG ranged from 1.3 to 50 mug/ml in these samples, but was undetectable (is less than 1 mug/ml) in matched controls. Since the abnormal samples included four cases of spina bifida and eight cases of anencephaly before 22 weeks of pregnancy, measurement of AMG concentrations may be useful in the early antenatal diagnosis of neural tube defects. In some cases it gave clearer results than those obtained by measurement of amniotic fluid alphafetoprotein. However, care must be excercised to ensure that amniotic fluids are not contaminated by blood.

One hundred women with pregnancies at risk for the recurrence of neural tube defects have entered our monitoring programme of echography and alphafetoprotein estimation (AFP) on amniotic fluid and maternal serum during the second trimester. The results of these pregnancies, the application of the programme, sources of error, and the reliability of alphafetoprotein levels are discussed. Conclusions regarding the value of the tests and routine antenatal screening are made.

Congenital miline dorsal malformations in infants most commonly represent spina bifida cystica or teratoma. The five patients reported here are a distinct clinicopathologic entity. They presented at birth with a dorsal midline mass, with no neurologic impairment, and no hydrocephalus developed subsequently. The lesions were removed in all infants without significant mobidity. The masses were comprised prinicipally of mesodermal elements, i.e., bone, cartilage, fat, muscle, and fibrous tissue. The well-differentiated cellular components, forming mature structures and the lack of primitive organoid structures as well as the absence of neoplastic characteristics, favors a diagnosis of hamartoma rather than of teratoma.