Showing papers on "Amniocentesis published in 1970"

Role of amniocentesis in the intrauterine detection of genetic disorders.

Abstract: One hundred and sixty-two transabdominal amniocenteses were performed between the thirteenth and eighteenth weeks of fetal gestation as part of the management of 155 "high-risk" pregnancies. Successful cultivation of amniotic-fluid cells led to the intrauterine detection of Down's syndrome (10 cases), Pompe's disease (one case), lysosomal acid phosphatase deficiency (one case) and metachromatic leukodystrophy (one case). The risk of this procedure is low since neither fetal nor maternal complications were demonstrated in this series of patients. Cultivation of amniotic-fluid cells obtained by transabdominal amniocentesis early in the second trimester of pregnancy provides a method that enables parents at "high risk" for having offspring with certain serious genetic disorders to have children without risk of such a defect.

Amniotic fluid cells; prenatal sex prediction and culture.

Abstract: Sex chromatin studies were carried out on small amounts of amniotic fluid obtained by amniocentesis or from intact amniotic sacs removed at hysterotomy. Provided that satisfactory preparations were obtained the accuracy of fetal sexing was 87%. Nevertheless, in the management of a pregnancy in which there is a risk of a serious X-linked recessive disorder, repeat amniocentesis may be necessary to ensure satisfactory specimens. Of 90 samples of fluid cultured, satisfactory growth was obtained in 49; the success rate was not increased by the addition of stimulants to the culture medium. It is suggested that between the 13th and the 16th week of pregnancy is the optimum time for amniocentesis to obtain cells for culture, since sufficient cells are then present in a small volume of fluid and therapeutic abortion would still be possible once the results were available.

Role of amniocentesis in the intrauterine detection of genetic disorders

Abstract: One hundred and sixty-two transabdominal amniocenteses were performed between the thirteenth and eighteenth weeks of fetal gestation as part of the management of 155 "high-risk" pregnancies. Successful cultivation of amniotic-fluid cells led to the intrauterine detection of Down's syndrome (10 cases), Pompe's disease (one case), lysosomal acid phosphatase deficiency (one case) and metachromatic leukodystrophy (one case). The risk of this procedure is low since neither fetal nor maternal complications were demonstrated in this series of patients. Cultivation of amniotic-fluid cells obtained by transabdominal amniocentesis early in the second trimester of pregnancy provides a method that enables parents at "high risk" for having offspring with certain serious genetic disorders to have children without risk of such a defect.

The pregnancy at risk for a genetic disorder.

Abstract: IN this week's issue of the Journal Nadler and Gerbie report the first large series of amniocenteses done around the sixteenth week of fetal gestation for prenatal genetic diagnosis — a new technic heralded in these columns a year ago.1 These authors have performed 162 amniocenteses in 155 pregnancies, and have collected 132 more cases from three other centers. First of all, this combined experience is reassuring because no complications were apparent in any mother or fetus. Although unlikely long-range effects must be excluded, it appears that the risk of amniocentesis at 16 weeks will be very low, as has . . .

Amniotic fluid cells; prenatal sex prediction and culture

Abstract: Sex chromatin studies were carried out on small amounts of amniotic fluid obtained by amniocentesis or from intact amniotic sacs removed at hysterotomy. Provided that satisfactory preparations were obtained the accuracy of fetal sexing was 87%. Nevertheless, in the management of a pregnancy in which there is a risk of a serious X-linked recessive disorder, repeat amniocentesis may be necessary to ensure satisfactory specimens. Of 90 samples of fluid cultured, satisfactory growth was obtained in 49; the success rate was not increased by the addition of stimulants to the culture medium. It is suggested that between the 13th and the 16th week of pregnancy is the optimum time for amniocentesis to obtain cells for culture, since sufficient cells are then present in a small volume of fluid and therapeutic abortion would still be possible once the results were available.

Fetal Skin Biopsy

Abstract: To the Editor.— In the article on amniocentesis (204:949, 1968), Creasman and associates noted that healing of fetal skin injuries due to amniocentesis might be rapid and complete. We would like to describe the procedures of fetal skin biopsy which may serve as a tool for prenatal detection of congenital defects. The pregnant woman lies supine. Guided by palpation and fixation of the fetus with assistant's hands, the Vim-Silverman biopsy needle with the obturator is introduced through the abdominal and uterine walls on the median line between symphysis and navel. When the needle is advanced slightly into the fetal tissue, the obturator is replaced with the inner split needle. Several pieces of fetal skin (about 1 mmX2 mm in size) are obtained by repeated splitting with the inner needle. So far this procedure has been tried for eight women who were in the second or third trimester of pregnancy

Antenatal paediatrics by amniocentesis.

Abstract: The finding that amniotic fluid contains living cells which may be cultured (Fuchs, 1966; Steele and Breg, 1966; Nadler, 1968) offers important and interesting prospects for antenatal paediatrics. There is, however, much yet to be learnt both about the safety of the operative procedure and about the techniques of culturing the cells. The only extensive experience of amniocentesis hitherto has been in relation to Rh-isoimmunization, and here the procedure is carried out later in pregnancy. The operation is best carried out suprapubically at the 12th to 14th post-conceptional week, with the withdrawal of 5 to 10 ml. amniotic fluid (Nadler, 1968). The risk of infection is small, the risk to the mother is small, the risk to the fetus is not yet reliably established. An approach through the anterior fornix may be made two or three weeks earlier, buit probably carries a higher risk of infection and of inducing abortion. The alternative procedure of chorion biopsy (Hahnemann and Mohr, 1969) also makes cells available two or three weeks earlier in pregnancy, but appears less reliable and less safe. The first application has been in genetic counselling: for the diagnosis of chromosome anomalies in pregnancies where the mother is already known to have a high risk of producing an abnormal child. An example is where a mother has a D/G translocation with perhaps a 1 in 5 chance of producing a liveborn child with Down's syndrome, and both parents are asking for a termination (Jacobson and Barter, 1967; Nadler, 1968). In this case the procedure is being used essentially to avoid the unnecessary termination of a normal pregnancy. In these circumstances the small risk of inducing an abortion by the procedure is acceptable, as is the small risk of damaging the fetus. The procedure has also been used when parents with similar risks have wished deliberately to plan a pregnancy on the understanding that if the fetus is found to be abnormal they will be offered a termination. Amniocentesis at the 14th week followed by 3 weeks of cell culture makes possible termination before the 18th week. A similar and more widespread potential use of amniocentesis in genetic counselling is where there is a high risk of an inborn error of metabolism. The list of metabolic errors detectable in amniotic cells is growing fast, and includes, for example, the autosomal recessive conditions, galactosaemia, cystathioninuria and homocystinuria, and the Xlinked conditions, the Lesch-Nyhan hyperuricaemia syndrome and G6PD deficiency. In these instances culture of the cells is unnecessary, and the enzyme deficiency, it is claimed, may be demonstrated directly on the cells in the amniotic fluid (Nadler and Gerbie, 1969). Amniocentesis has already been used where the mother was a known carrier of the gene for the Lesch-Nyhan syndrome (Fujimoto et al., 1968). In other instances, for example in Hurler's syndrome, some weeks of culture are at present necessary before the accumulation of mucopolysaccharides is demonstrable, and here the homozygote cannot be distinguished reliably from the heterozygote (Danes and Beam, 1966). There is, however, a good chance that the metabolic errors that are demonstrable in fibroblast culture-and this includes most of them, with phenylketonuria a notable exception-will also be demonstrable in amniotic cell culture. A biochemical test for the fetus with cystic fibrosis would be especially valuable and the demonstration of metachromasia in both fibroblast and lymphocyte culture (Danes and Beam, 1969) from such patients suggests that such a test may not be too far away, though the metachromasia itself is too non-specific to be useful. The prevention of conditions such as cystic fibrosis is likely to come from the detection before they marry of the 5% of the population in Britain who are heterozygotes, combined with the offer of pregnancy testing for homozygous fetuses when two heterozygotes do marry each other. Looking to future advances, a test for women heterozygous for the gene for X-linked muscular dystrophy combined with a test for the male fetuses who are hemizygous for the gene would be of great value, and permit a reduction of the frequency of affected boys to those affected by a fresh mutation-perhaps to about a third of the present frequency. There is even a prospect that amniocentesis may play a

Rhesus incompatibility--an assessment of the hazards of amniocentesis, and the effect of liquor volumes on amniocentesis prediction.

Abstract: Summary The complications of 185 amniocenteses have been analysed. The failure rate of the procedure was 11.3%. Spontaneous rupture of the membranes and premature labour occurred in 2.2%. In 33% of patients fetal cells were found in the liquor and feto-maternal haemorrhage occurred in 38%. The presence of fetal cells in the maternal circulation was followed by an increase in maternal sensitisation in 4 of 16 patients. Intra-uterine fetal death can occur from feto-maternal haemorrhage. A suprapubic approach for amniocentesis decreases the incidence of feto-maternal transfusion. Placental localization is essential to avoid feto-maternal transfusion. In 25 patients differences in liquor volume had no effect on the accuracy of amniocentesis prediction.

Instrument-Dependent or Instrument-Independent Indications and Prevalence of Chromosomal Abnormalities by Amniocentesis in China: An Analysis of 4146 Cases of Amniocentesis

Abstract: Objective: There is a high incidence of birth defects in China, and prenatal diagnosis is an important method of intervention. This study aims to describe the clinical indications and cytogenetic results of amniocentesis cases in central China. Methods: We retrospectively reviewed cases at the Maternal and Child Care Service Centre in Henan Province from January 2012 to December 2014. A total of 4497 at-risk mothers (risk factors: advanced maternal age, history of intrauterine fetal death or aborted fetuses, chromosomal abnormality in one of the parents, high-risk maternal serum screening results, and abnormal ultrasonographic findings in the first or second trimester) were recruited for amniocentesis (AS). The subjects included were between 11–14 and 18–22 weeks of gestation. All cases were divided into two groups based on instrument-independent or instrument-dependent indications. Results: A total of 4146 cases were analyzed. Of these, chromosomal abnormalities were detected in 232 cases (5.6%), and autosomal aneuploidy, including trisomy 21 and trisomy 18, was found to be the most common (55.7%) chromosomal abnormality. The mean age of 29.94 years was not expected as all mothers older than 35 years old were routinely offered amniocentesis at the time of the study. Amniocentesis was carried out in 1711 cases because of instrument-independent indications, and 285 of these cases were diagnosed with chromosomal abnormality. In 2376 cases, amniocentesis was conducted because of instrument-dependent indications, and 176 of these were diagnosed with chromosomal abnormality. Thus, 5.6% of the cases were diagnosed with chromosomal abnormalities, and autosomal aneuploidy, including trisomy 21 and trisomy 18, were the most common chromosomal abnormalities detected in the present study. Conclusion: Our result indicated the significance of instrument-independent indications in the screening of chromosomal abnormalities, especially in developing areas. Birth defects may be reduced by paying more attention to the patients’ history of medication.