[Clinical study of assessment of trisomy 21--precise risk evaluation in the first trimester of pregnancy]

BACKGROUND

In the past a non invasive risk analysis for detecting specific chromosomal aberrations was only possible from week 15 of pregnancy. In this paper the practicability of first trimester screening is analysed.

MATERIAL AND METHODS

Blood samples were taken from 1000 pregnant women before a invasive prenatal diagnosis was performed. Total hCG, free beta-hCG and PAPP-A (pregnancy associated plasma protein A) was analysed. These data were combined with complete cytogenetic and ultrasonographic (CRL and nuchal translucency--NT) data.

RESULTS

In more than 90% of cases the NT was below 3 mm. Here the rate of normal karyotypes was 97.8%. In 61 cases a abnormal karyotype was found. Here in the most cases we found an elevated NT. Also in the most cases of trisomy 21 and 18 and in triploidies a characteristic ratio of hCG/free beta-hCG and PAPP-A was discovered. Combining NT and biochemical analysis, 85% of trisomies 21 could be discovered as a risk group.

CONCLUSIONS

This study demonstrates the possibilities of first trimester screening with a high detection rate for specific chromosomal aberrations.

DISCUSSION

First trimester screening should only be performed in specialised centers because determination of NT and risk analysis needs extensive experience.

Rapid prenatal diagnosis of aneuploidies in uncultured amniocytes by fluorescence in situ hybridization. Evaluation of >3,000 cases

OBJECTIVE

A new method in prenatal diagnostics allows to demonstrate certain numeric chromosomal aneuploidies in amniotic cells within 24 h in contrast to conventional methods which take 1-3 weeks.

MATERIALS

The experience with this rapid fluorescence in situ hybridization (FISH) method is compared to standard karyotyping and its clinical relevance is described in a large clinical pilot study. FISH on uncultured amniocytes has been performed from 12 weeks of gestation to the third trimester using commercially available chromosome-specific DNA probes for chromosomes 13, 18, 21, X and Y.

RESULTS

FISH was performed successfully in 3,150 prenatal cases. All trisomies 13, 18 and 21 and all cases with gonosomal aberrations were detected by FISH analysis. Neither false-positive nor false-negative results were obtained using FISH. For all analyzable disorders the FISH results were in complete agreement with standard cytogenetics.

CONCLUSIONS

In our experience, FISH is a valuable and reliable method for rapid diagnosis of numeric chromosomal aneuploidies.

A prospective comparative study on fluorescence in situ hybridization (FISH) of uncultured amniocytes and standard karyotype analysis

Fluorescence in situ hybridization (FISH) on uncultured amniocytes and standard cytogenetic analysis after amniocentesis have been performed for 904 samples. The experience with the FISH method and its clinical relevance is described in a large clinical pilot study. Commercially available chromosome-specific DNA probes for chromosomes 13, 18, 21, X and Y were used. FISH assays were performed from 12 weeks of gestation to the third trimester. In 96 per cent of the cases, hybridization was performed successfully. At least 50 nuclei for all probes could be counted in 88 per cent of the cases and in 8 per cent between 10 and 49 nuclei were scored. All trisomies 13, 18 and 21 and all cases with gonosomal aberrations were detected by FISH analysis with the exception of one case of trisomy 21 in which hybridization failed due to technical problems. Neither false-positive nor false-negative results were obtained with the DNA probes, in complete agreement with standard cytogenetics. In our experience, FISH is a valuable and reliable method for rapid diagnosis. Consequences of FISH diagnosis are discussed.

On the complication risk of early amniocentesis versus standard amniocentesis

In the last 6 years early amniocentesis for the prenatal diagnosis of chromosome aberrations has been established in many centers worldwide, but knowledge about the gynecological safety of the procedure is sparse. From 1990 to 1995 at the Evangelisches Krankenhaus Oberhausen (Germany) 3,277 early amniocenteses (between weeks 11 and 14) and 1,808 standard amniocenteses were performed in low-risk indication groups (advanced maternal age and anxiety). A complete follow-up including reports of fetal outcome was obtained in 4,444 cases (87.5%). A pregnancy age-related abortion rate was determined with a slightly higher rate of abortions up to week 28 of gestation in early amniocentesis. The total abortion rate up to week 28 after the procedure for cases with complete follow-up was 2% in early amniocentesis. Compared to standard amniocentesis performed under the same clinical conditions with an abortion rate of 1.3%, there is no statistical difference between early and standard amniocentesis (p = 0.0971). Hip and foot dislocations (22 cases) and pulmonary distress syndromes (8 newborns) showed no significant correlation with the gestational week. Given the high normal background rate of spontaneous abortions in the early period of pregnancy without an invasive procedure, early amniocentesis can be considered as a safe alternative to chorionic villus sampling and standard amniocentesis.

Early amniocentesis--a cytogenetic evaluation of over 1500 cases

We report our cytogenetic experience of 1554 early amniocenteses between weeks 11 and 14 of gestation, of which 44 per cent were performed prior to week 14. The mean culture time was 14.5 days. Karyotyping was successful in 99.7 per cent of cases. In 9.9 per cent of cases, there was pseudomosaicism with a high rate of loss of an X-chromosome and structural aberration of chromosome 1, which may be due to the Chang medium. The mosaic rate was 0.5 per cent. The overall aberration rate was 2.8 per cent. Our data confirm the reliability of early amniocentesis, which is a serious alternative to standard amniocentesis and chorionic villus sampling (CVS).

[Early amniocentesis between the 12th-14th week of pregnancy. Clinical experiences with 1,100 cases]

Information is presented on 1100 early amniocenteses between the 12th and 14th week of gestation, performed at the Evangelisches Krankenhaus Oberhausen over a two year period. In all cases, a sufficient amount of amniotic fluid was obtained. In 99.7%, the cytogenetic diagnosis was successful. In 2.6% (29 patients), an aberrant karyotype was found. The time of cultivation was in the same range as can be observed in standard amniocentesis. The AFP-median measurements correlate with other studies. The spontaneous abortion rate was 0.3%. We conclude, that early amniocentesis can be performed safely and successfully by an experienced surgeon between the 12th to 14th week of gestation.

Prenatal diagnosis of monosomy 18 and ring chromosome 18 mosaicism

The case of monosomy 18/ring chromosome 18 mosaicism which was detected prenatally by amniocentesis is presented. The pregnancy was terminated in week 18. Autopsy showed complex malformation of the fetus consisting of cebocephaly, hypotelorism, microphthalmia, severe defects of brain development, and arrest of placental maturation.

[CIN and pregnancy, a 20-year retrospect]

This is a report on CIN associated with pregnancy in a review over the last 20 years. Biological tumour behaviour, diagnostic problems and therapy are discussed in 100 cases of preinvasive and invasive lesions of the cervix. It is pointed out that low acceptance of early detection measures in association with late pregnancy planning may contribute to an increase of invasive cancer in pregnancy.

Cytogenetic analysis of 750 spontaneous abortions with the direct-preparation method of chorionic villi and its implications for studying genetic causes of pregnancy wastage

Altogether, 750 cases of spontaneous abortion between the fifth and 25th week of gestation were analyzed cytogenetically by the direct-preparation method using chorionic villi. The majority of cases (68%) were derived from early abortions before the 12th week of gestation. The frequency of abnormal karyotypes was 50.1%; trisomy was predominant (62.1%), followed by triploidy (12.4%), monosomy X (10.5%), tetraploidy (9.2%), and structural chromosome anomalies (4.7%). Among trisomies, chromosomes 16 (21.8%), 22 (17.9%), and 21 (10.0%) were prevalent. The frequency of chromosomally abnormal abortions increased with maternal age but only because of an increase of trisomy. Polyploidy and monosomy X, however, decreased. Mean maternal age was significantly increased for trisomies 16, 21, and 22 and was highest for trisomies 18 and 20. The results obtained are within the range of variability reported earlier from tissue culture-type studies. A consistent feature during our study is the excess of females in chromosomally normal abortions (male:female sex ratio 0.71). According to the methodology applied, maternal cell contamination and undetected 46,XX molar samples cannot have influenced the sex ratio. However, a bias introduced by social status or maternal age cannot be excluded. With the more rapid and convenient direct preparation of chorionic villi, reliable cytogenetic data on causes of spontaneous abortions can be obtained.

[Cytologic endometrium diagnosis with a new combination instrument, the Endoshave]

We report on 300 examinations with a new one-way instrument for taking cell material from the uterus for cytodiagnosis. A combination of shaving and aspiration and the technical form similar to the uterus guarantee a high probability of complete collection and excretion of cell material from all parts of the cavum uteri and the cervix. A regular screening of all women with high risk seems to be possible with this cell collector.

Tissue-specific 45,X0/47,XY,+13 mosaicism in an 18-year-old woman

The case of an 18-year-old woman with a 47,XY,+13 karyotype in lymphocytes and a 45,X0 karyotype in all other tissue analyzed is presented. The proposita shows no stigmata of the Patau syndrome and no masculinization.

Translocation trisomy 21 in CVS not found in embryoblast: three different cell lines in CVS, amnion- and placental culture

Chorionic villus samples from a healthy pregnant female were obtained for first-trimester prenatal diagnosis. A translocation trisomy 21 was diagnosed. A consecutive amniocentesis revealed a normal male karyotype. At term a healthy boy was born. Cytogenetic analysis from cord blood showed a regular karyotype of 46,XY, whereas in term placenta a pathological karyotype of 47,XY, +mar was found.

Chromosomal rearrangement involving chromosomes 4, 6, 11 and 11

The case of a healthy 29-year-old woman is reported who had a history of three early spontaneous abortions. Chromosomal analysis of the mother of the patient showed a balanced karyotype of 46,XX,t(6;11) (q24; q21), whereas the chromosomes of her father were normal. The karyotype of this patient is thus a combination of a familial translocation 6;11 and a de novo translocation 4;11, which is very rare.

[Long-term study of endometrial cell sampling and cytologic evaluation with special reference to Prevical and Curity]

The special anatomic approach and difficult cell collecting from all parts of the corpus uteri have so far prevented the development of an ideal instrument for an early detection of endometrial adenocarcinoma. During the past 9 years we examined several methods; this is a report of a long-term study on 2,500 smears with Prevical and 320 with the Isaacs endometrial cell sampler. In particular, the difficulties concerning the highly differentiated carcinoma and all precancerous abnormalities are discussed, and the increasing number of endometrial carcinomas in comparison with those of the cervix uteri are confirmed. In the near future the control of all patients with high risk is recommended, beginning with the age of 40-45. A further aim is to solve cytomorphological and instrumental problems with regard to screening all precancerous stages without exception.

[Problems on early detection of the endometrial adenocarcinoma with a critical examination of jet-wash and curity-technique (author's transl)]

The difficulties to find an appropriate screening-technique for the recognition of endometrial adenocarcinoma are described. Some methods of the last ten years are mentioned, advantages and disadvantages are shortly debated. Our clinical study contains 100 patients, who were examined by the jet-wash or curity-method with following abrasion. Practicability, security and the agreement of both techniques with histological results are compared. The most serious objection against jet-wash is the abdominal spreading of cells along the tubes. Curity-screenings are yet carried on with good results.

[The untreated congenital adrenogenital syndrome on the light of modern diagnosis and individualized treatment (author's transl)]

A case of untreated adrenogenital syndrome in a 19 year old patient is described. The patient refused treatment and a name and sex change was effected in the registry following psychiatric consultation. The clinical, genetic and psychological problems of the adrenogenital syndrome are discussed. The importance of early diagnosis and treatment are again emphasized.

[Paresis of the femoral nerve following vaginal hysterectomy and its medico-legal implication (author's transl)]

Following the North American example, mal-practice suits become more common in Germany. The rare complication of a paresis of the femoral nerve following vaginal hysterectomy is reported. Among 1307 vaginal hysterectomies, including 33 radical vaginal hysterectomies between 1969 and 1974, three cases occurred. In one case, the surgeon was sued but the patient lost the mal-practice suit. In another case a diminished employability was recognized later. The causes and the prevention of damage of the femoral nerve during vaginal procedures are discussed.