Showing papers on "Amniocentesis published in 1980"

Prenatal diagnosis of hemoglobinopathies.

Abstract: In the five years following the last Cooley's Anemia meeting, prenatal diagnosis of the hemoglobinopathies has changed from a laboratory investigation to a technique that is being actively applied to pregnancies at risk in several countries.', * The methodology of prenatal diagnosis is also evolving rapidly. Whereas fetal blood sampling analysis was initially the sole method available, the rapid advances in the field of molecular biology are now being applied at the clinical level, making it possible to utilize amniocentesis for many cases of prenatal diagnosis. Sickle-cell anemia, B thalassemia, and CL thalassemia are the three defects affecting globin synthesis where prenatal diagnosis is indicated. These diseases occur with high frequency in defined populations and are usually of sufficient clinical severity to warrant prenatal diagnosis. Since other hemoglobinopathies are rare, and most have little clinical effect, the need for prenatal diagnosis of these other disorders will be infrequent. There are several different approaches currently used for prenatal diagnosis of the three conditions. In the majority of cases of sickle-cell anemia in the United States, prenatal diagnosis with amniocentesis is possible, with the minority still amenable to diagnosis only with fetal blood sampling. However, in nearly all cases of thalassemia, fetal blood sampling is still the sole method available. In homozygous a thalassemia, prenatal diagnosis by amniocentesis is possible in all cases.

Properties of fetal and adult red blood cell arginase: a possible prenatal diagnostic test for arginase deficiency.

Abstract: Prenatal diagnosis of inborn errors of metabolism has been possible only if the enzyme affected is expressed in amniotic fluid cells grown in culture. Arginase is essentially undetectable in normal human fibroblasts, amniotic fluid, and amniotic fluid cells but is present in high amounts in red blood cells. It is absent in the red blood cells of patients with liver arginase deficiency. The properties of the enzyme in the red cells of healthy children and adults were compared to those of the enzyme obtained from cord blood red cells of 13--20-week fetuses obtained at hysterotomy. The activities, heavy metal requirements, heat stability, pH optimum, kinetic properties, and reaction with anti-arginase antibody were examined. Both enzyme species were either identical or substantially similar by all criteria. The adult and fetal enzymes are, therefore, probably determined by the same structural gene. Fetal red cells obtained during amniocentesis and amnioscopy should then be a suitable tissue to use to make the prenatal diagnosis of arginase deficiency.

Antenatal diagnosis of glutaric acidemia.

Abstract: Two pregnancies at risk for glutaric acidemia were monitored. In one, in which the fetus was not affected, glutaric acid was not detected in the amniotic fluid at amniocentesis (15 weeks) and the glutaryl-CoA dehydrogenase activity of cultured amniotic cells was normal. In the other, a marked elevation of glutaric acid in the amniotic fluid, together with deficiency of glutaryl-CoA dehydrogenase in amniotic cells, prompted termination of the pregnancy, and studies on the abortus confirmed the diagnosis of glutaric acidemia. Glutaric acidemia, is, thus, another inborn error of metabolism which can be diagnosed in utero.

Stress after amniocentesis for high serum alpha-fetoprotein concentrations.

Abstract: SIR,-In his review of maternal serum afetoprotein (AFP) screening in pregnancy (17 May, p 1199) Rodney Harris concludes that one potential benefit of population screening might be the identification of fetuses at risk of spontaneous abortion, low birth weight, or perinatal death. He bases this conclusion on the increased incidence of these problems among women who have a high maternal serum AFP concentration but a normal result on amniocentesis. The possibility that the prenatal diagnostic intervention may have caused the subsequent problems is discounted by reference to the significantly better pregnancy outcome of women who have amniocentesis for other reasons. An outcome measure which receives no attention in Harris's review, but which I have found to be significant in differentiating women with high serum AFP concentrations from those with other indications for amniocentesis, is the woman's emotional reaction to the diagnostic intervention.' The data in the table are based on interviews with 90 women who had a normal result on amniocentesis. Although nearly all women were worried about

The Down syndrome in the fetus

Abstract: A significant number of fetuses with the Down syndrome are spontaneously lost before birth; however, very few such fetuses have been described. In the present study, 13 fetuses of 127--180 mm in crown-rump length were examined following amniocentesis diagnosis of trisomy 21 and therapeutic abortion. Four features, i.e., simian crease, clinodactyly, septal heart defects, and decreased size, were found to be relatively common in trisomy 21 fetuses as compared to controls. Other features were found to be less useful in identification. We conclude that the presence of two of the four features noted above is suggestive of trisomy 21 in the fetus.

Reactions to prenatal diagnosis: an analysis of 87 interviews.

Abstract: Prenatal diagnosis, which enables certain fetal anomalies to be detected in utero, is becoming increasingly common among the growing number of women who, through choice or circumstance, experience pregnancy late in their childbearing life. Based on interviews with 62 women and 25 of their male partners, psychological responses to amniocentesis are discussed with respect to the medicalization of pregnancy, differences in reactions of women and men, the foreknowledge of the child's sex, the significance of pregnancy after 40, and the impact of an unfavorable diagnosis.

The pipette method: a new rapid technique for chromosome analysis in prenatal diagnosis.

Abstract: A new method has been developed to abridge the time between amniocentesis and chromosome analysis in prenatal diagnosis. With this method cells in metaphase are separated from the clones by a micropipette with the help of a micromanipulator and then prepared.

Porencephalic cysts after amniocentesis.

Abstract: An infant with porencephalic cysts associated with midtrimester amniocentesis is reported. CNS anomalies after amniocentesis have not been reported in live neonates.

Two conceptions in a 45,X woman.

Abstract: We present a 31-year-old woman with a 45,X chromosome constitution who had had two miscarriages. This report brings to 11 the number of presumably non-mosaic Ullrich-Turner syndrome patients who have achieved pregnancy. A review of the literature indicates an increased incidence of chromosome abnormalities and a high rate of fetal death in offspring of such patients. However, in light of the fertility in these patients, genetic counseling should be reevaluated and perhaps amniocentesis recommended in successful pregnancies.

Prenatal genetic diagnosis and elective abortion in women over 35: utilization and relative impact on the birth prevalence of Down syndrome in Washington State.

Abstract: We have examined the relative contributions of a population-based antenatal detection program and unrestricted elective abortion used by women 35 years old and over in Washington State and King County for 1976--1977 to the declining birth prevalence of Down syndrome (DS). The amniocentesis/live birth (LB) ratio for women 35 years old and over was 20.5/100 LBs for King County and 11.7/100 LBs for Washington State in 1977. For the state in 1976, abortion ratios/1,000 LBs were 571 for women 35 to 39 years old and 1,096 for women 40 years old and over. Based on the total Washington State data, elective abortion has a greater impact on averting DS births than does the antenatal detection program. The impact of elective abortion appears to be related to its disproportionate use by women 35 years old and over compared to their contribution to the population of of LBs.

Concentrations of oxytocin in the plasma and amniotic fluid of rhesus monkeys (macaca mulatta) during the latter half of pregnancy

Abstract: A specific radioimmunoassay for oxytocin has been established with a sensitivity of 0.8 pg/tube. This assay has been applied to the measurement of oxytocin in serial samples of peripheral plasma and amniotic fluid from pregnant rhesus monkeys, collected at weekly intervals by venepuncture and amniocentesis. Concentrations of oxytocin in both fluids were generally low and showed no trends throughout the latter half of gestation.

Influence of obstetricians' attitudes on their use of prenatal diagnosis for the detection of Down's syndrome.

Abstract: Practising obstetricians were surveyed to determine the relation between their referral patterns and their knowledge and attitudes concerning prenatal diagnosis by amniocentesis for women aged 35 years and over. Although 82% had referred at least one eligible patient for prenatal diagnosis during the past year, almost none had used the available services for all appropriate patients. There was a statistically significant trend for increased referral as correct knowledge of the risks and accuracy of prenatal diagnosis increased. Moreover, a discriminant function combining risk and accuracy estimates, type and size of practice, and language distinguished the referrers from the nonreferrers (P = 0.0002), although there was considerable overlap between the physicians classified according to a high, moderate or low rate of referral. The data suggest that while knowledge and practice characteristics can distinguish obstetricians who refer patients for prenatal diagnosis from those who never do so, the frequency of referral may involve other factors, such as how physicians accept innovation and perceive risks.