Pressures on the fetal head during normal labor.

The pressure recordings from both parietal regions of the fetal head during the second stage of labor of 44 spontaneous deliveries with vertex presentation were evaluated and compared to the simultaneously recorded pressures in the amniotic cavity by calculating pressure parameters during and between uterine contractions. Analysis of the bearing down period revealed on the average higher values at the anterior side in comparison to the posterior side of the skull. This is explained by the complex anatomy of the curved birth canal. Overall, the head pressure values averaged from the recordings of both parietal regions were about twice as high as the corresponding amniotic pressure values. During the descend of the head through the birth canal, an increase of pressure on the fetal head was observed that is mainly due to the rising resistance of the narrowing pelvis and stretched tissue of the passageway. A marked interindividual deviation of head pressure was found that was independent from amniotic pressure variations thus preventing indirect deduction of head strain from internal togography.     

Color flow mapping of the middle cerebral artery in 23 hydrocephalic fetuses

Color flow mapping was performed on 23 fetuses with hydrocephaly. The measurements on the middle cerebral artery posed no problem. We found end-diastolic frequencies in all cases. The pulsatility-indices were raised in only 4 cases. Color Doppler sonography gave no extra information about diagnosis or prognosis. Correspondence to: R. Mai     

Prenatal diagnosis in a family with severe type I plasminogen deficiency, ligneous conjunctivitis and congenital hydrocephalus

Severe type I plasminogen deficiency may cause severe ligneous conjunctivitis, a rare and unusual form of chronic pseudo-membranous conjunctivitis that usually starts in early infancy, but also pseudo-membranous lesions of other mucous membranes in the mouth, nasopharynx, trachea and female genital tract, and in rare cases congenital occlusive hydrocephalus. The index patient, the daughter of a consanguineous marriage, had suffered from severe ligneous conjunctivitis and had died from decompensated congenital hydrocephalus despite numerous shunt revisions. She was found to be homozygous for a non-sense mutation in exon 15 of the plasminogen gene (Trp597->Stop). In her next pregnancy, the mother asked for prenatal diagnosis of the plasminogen deficiency. Chorionic villus biopsy was performed at 12 weeks of gestation. DNA analysis of the plasminogen gene by PCR and single-strand conformation polymorphism (SSCP) revealed that the fetus exhibited an identical heterozygous band pattern as observed in the healthy mother. Therefore, the fetus was heterozygous for the Trp597->Stop mutation in plasminogen exon 15. In addition, the fetus was found to be male by cytogenetic analysis and by multiplex PCR analysis using two polymorphic X-chromosomal markers (DXS424, HPRT). These findings excluded the possibility of contamination by maternal DNA. It was concluded that the fetus was not at risk for ligneous conjunctivitis and its associated complications. After the birth of a healthy boy, plasminogen functional activity was shown to be 38 per cent. DNA analysis confirmed prenatal molecular genetic results.     

Measurement of head compression during labor: preliminary results

To study the pressure to which the fetal head is exposed during the second stage of labor, an instrument was designed to measure continuously the pressure between the presenting part and the birth canal on both sides of the fetal head. Pressure parameters during and between the uterine contractions were calculated from 42 spontaneous vertex deliveries presenting as occiput anterior. During the second stage the overall average of the mean maximum head pressure during uterine contraction was 31.8 +/- 11.0 kPa, that of the mean head pressure measured 13.3 +/- 4.8 kPa during uterine contraction and 5.5 +/- 3.7 kPa during the interval between contractions. The pressure on the fetal head was about twice as high as the amniotic pressure. It increased towards the end of labor. The objective measurement of fetal head pressure is the prerequisite in the study of the relationship between birth-related injuries and excessive head compression during parturition.     

Differential diagnosis of sonographically detected tumours in the fetal cervical region

Differential diagnosis of sonographically detected fetal neck tumours is difficult. The sonographic criteria for encephalomyelocele, lymphangioma/hygroma, teratoma, sarcoma, haemangioma, neuroblastoma and goitre are given on the basis of the authors' own observations and information from the literature. Elevation of alpha-fetoprotein in the amniotic fluid is a frequent but non-specific finding. Chromosome analysis after amniocentesis can be a useful supplementary procedure for assessing the prognosis and deciding upon the delivery procedure. Sonographic detection of a tumour in the fetal neck region enables preparations to be made for dystocia and postnatal dyspnoea of the newborn. The obstetrician must cooperate closely with paediatricians, neurologists, surgeons and ENT specialists.     

Beziehung der kindlichen Kopfkompression sub partu zu perinatalen Faktoren

Ohne Zusammenfassung