G. Szeifert

Prenatal diagnosis and pathoanatomy of iniencephaly

The authors discuss the diagnostic criteria of iniencephaly based on data from the literature and eleven additional, new cases. The most important differential diagnostic problems involve anencephaly with spinal retroflexion and the Klippel‐Feil syndrome. Ultrasound indicated cranio‐spinal alterations while amniotic fluid AFP estimation and exfoliative cytology substantiated abnormal closure of the neural tube, thus comprising helpful means for prenatal diagnosis of iniencephaly. The authors emphasize the need for median‐sagittal sectioning through the spinal column for accurate evaluation of vertebral abnormalities. This, together with close observation of the occiput and the foramen magnum, helps the precise diagnosis of iniencephaly and once regularly applied will most likely result in more frequent recognition of this developmental abnormality.

Prenatal diagnosis of X linked hydrocephalus without aqueductal stenosis.

The outcome of four successive pregnancies in a woman heterozygous for X linked hydrocephalus is described. The last two were scanned by ultrasound. In one, a good prognosis was given; the fetus was male but there was no evidence of dilated cerebral ventricles. In the other, hydrocephalus was diagnosed. The absence of aqueductal stenosis in this case supports the hypothesis that in this X linked condition communicating hydrocephalus is the primary defect and aqueductal stenosis is secondary.

Prenatal diagnosis of cystic fibrosis by trehalase enzyme assay in amniotic fluid

Amniocentesis and amniotic fluid trehalase enzyme assay were offered to 14 pregnant women at a 1 in 4 risk for a child with cystic fibrosis. Twelve of these pregnancies were screened at the 18th week of gestation; ten proceeded to term, seven following the finding of a normal trehalase activity and three despite the low enzyme level in amniotic fluid. In all ten cases prenatal diagnosis proved to be correct. In two cases with low enzyme activity parents opted for termination at the 19th week, and with PAS‐Alcian Blue staining some slight histochemical lesions characteristic of cystic fibrosis were seen in the exocrine glands, including the pancreas and intestinal mucosa, of both fetuses. The total protein content in the meconium of these fetuses was significantly higher than in the controls.

Early prenatal diagnosis of cystic fibrosis by ultrasound.

Sirs, We have recently shown that trehalase assay in the amniotic fluid is a potential prenatal test for cystic fibrosis (Szabo et al. 1984, 1985) and that in fetuses with cystic fibrosis slight deviations can be observed on histochemical and biochemical study as early as the 17th week of gestation (Szab6 et al. 1985, Szeifert et al. 1985). We have also demonstrated fetal meconium ileus by ultrasound at the 28th week of gestation by dilated intestinal lumens and unusual intensive echogenic abdominal mass which was associated with cystic fibrosis detected by low trehalase activity in amniotic fluid at the 18th week (Szabo et al. 1985). When we realized that meconium ileus was detectable by ultrasonography, we decided to perform careful real-time scanning of the fetal abdomen at the time of the amniocentesis performed in pregnancies at a 1 in 4 risk of cystic fibrosis. Until now five pregnancies have been monitored by ultrasound in addition to the amniotic fluid enzyme assay. In four cases both enzyme activities and ultrasound findings were normal, and these pregnancies proceeded to term. All resulted in children not affected with cystic fibrosis. However, in a pregnancy at a 1 in 4 risk of cystic fibrosis, ultrasound examination (Picker LS 2000) showed an echo-rich unusual mass in the fetal abdomen at the 15th gestational week. The trehalase enzyme activity in the amniotic fluid sample taken by transabdominal amniocentesis was low (0.443 U/g). The amniotic fluid was unusually viscous and of greenish colour. Two weeks later the dense echogenic area was more evident by ultrasound (Fig. 1). The couple refused a further amniocentesis and requested termination. Abortion was induced and the female fetus weight, 170 g, was autopsied two hours after delivery. The large intestine of the fetus contained inspissated meconium closely attached to the mucosa and this caused wide dilation of the crypts and flattening of the lining epithelial cells (Szeifert et al. 1985). More recently we also scanned a case of fetal meconium peritonitis. A 24-year-old patient was referred to our genetic counselling clinic because of polyhydramnios at the 24th week of her first pregnancy. The scan-

Exencephaly in human fetuses

In some anencephalic fetuses exposed neural tissue mass of varied size can be demonstrated. This is known as exencephaly. The authors diagnosed by ultrasound 10 typical exencephalic cases prenatally between 14 and 21 weeks of gestation. Nine singular pregnancies were terminated and in the twin pregnancy a selective feticide of the exencephalic co‐twin was carried out. The pregnancy continued to term and a healthy newborn infant and a fetus papyraceus were born. The mummified co‐twin was anencephalic and showed only the remnants of the exposed brain.

Morphology of cystic fibrosis at 17 weeks of gestation

Sirs, We have recently shown that some histological and biochemical abnormalities can be observed in fetuses with cystic fibrosis at 19 weeks of gestation (Szabo et al. 1985). More recently we diagnosed a case of fetal cystic fibrosis by low amniotic fluid trehalase enzyme activity and by ultrasound at an even earlier stage of gestation (Papp et al. 1985), and we present here the morphological changes found in the fetus. In a pregnancy at a 1 in 4 risk of cystic fibrosis, ultrasound at the 15th gestational week showed an echo-rich unusual mass in the fetal abdomen. The trehalase enzyme activity in the amniotic fluid sample taken by transabdominal amniocentesis was low (0.443 U/g) (Szabo et al. 1984, 1985). The amniotic fluid was unusually viscous and of greenish colour. Two weeks later the dense echogenic area was more evident by ultrasound. The couple refused a further amniocentesis and requested termination. The abortion was induced using 100 ml of 0.1 % Rivanol solution injected transcervically into the extra-amnia1 area, with an oxytocin drip infusion the following day. The female fetus weighed 170 g and was autopsied two hours after delivery. Dissected samples from various tissues were fixed in 8% formaldehyde-ethanol solution for 48 h, dehydrated in graded alcohols, and embedded in paraffin. The 5 pm sections were stained with Alcian blue-PAS (pH 2.9). The most obvious alterations were found in the intestinal tract. There was intensive goblet cell hyperplasia with strongly alcianophilic mucinous material in the lumen, and the bulging goblet cells seemed to crowd out the intervening columnar epithelium in some places (Fig. l a and lb). Otherwise the small intestinal villous and microvillous architecture seemed to be normal. The large intestine was inspissated with dense meconium closely attached to the mucosa and this caused wide dilatation of the crypts and flattening of the lining epithelial cells (Fig.