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R. Douglas Wilson 《黑龙江环境通报》1995,15(13):1259-1273
Early amniocentesis at less than 14 weeks gestation is becoming more common in prenatal diagnosis populations. Randomized studies are minimal and have not had the power to determine the accuracy and safety of the procedure compared to chorionic villus sampling or mid-trimester amniocentesis. Procedures at 11+0-12+6 weeks should be considered experimental. This clinical review considers the ethics, embryology, and clinical experience (cytogenetics, AFP, AChE, procedure and cytogenetic failures, spontaneous and therapeutic pregnancy losses, congenital anomalies) of early amniocentesis. 相似文献
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Giovanni Monni Cristina Rosatelli Angela M. Falchi Maria T. Scalas Maria Addis Liliana Maccioni Anna Di Tucci Teresa Tuveri Proffessor Antonio Cao 《黑龙江环境通报》1986,6(1):63-68
This paper reports the results of first trimester prenatal diagnosis in a twin pregnancy at risk for homozygous β°−thalassaemia (β°−39 mutant). Trophoblast samples from both twins were obtained at 10 weeks gestation with a forceps guided by ultrasound. Trophoblast DNA analysis, carried out with the oligonucleotide technique, revealed that one fetus was homozygous and the other heterozygous for the β−39 mutant. This diagnosis was confirmed at 17 weeks gestation by amniocyte DNA analysis. DNA polymorphism analysis within the α-globin gene provided useful genetic markers for twin differentiation. 相似文献
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H. Brandenburg J. H. P. Der Van Meulen M. G. J. Jahoda J. W. Wladimiroff M. Niermeijer J. D. F. Habbema 《黑龙江环境通报》1994,14(4):243-256
Genetic counselling in a dizygotic twin pregnancy is complicated by the large number of possible pregnancy outcomes and by the conceivable differences in the parental valuation of these outcomes. We present the probability distributions of the pregnancy outcomes in dizygotic twin pregnancies for women from 35 to 45 years old without prenatal diagnosis and with transabdominal chorionic villus sampling (TA-CVS) or amniocentesis (AC), using data from the literature. TA-CVS always gives a higher probability of a favourable pregnancy outcome (the birth of one or two infants with a normal karyotype) than AC. For a 35-year-old woman, a 0·7 per cent risk of an unfavourable pregnancy outcome without prenatal diagnosis has to be weighed against the 2·1 per cent excess risk of loss of the entire pregnancy after TA-CVS. For a 45-year-old woman, a 10·2 per cent risk of an unfavourable pregnancy outcome without TA-CVS has to be balanced against a 4·4 per cent excess risk of pregnancy loss after TA-CVS. This study provides a quantitative tool for the support of individual parents with respect to the decision to undergo prenatal diagnosis in a dizygotic twin pregnancy. 相似文献
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