to reduce the prenatal mortality and morbidity and Ultrasound Screening The objectives of ultrasound screening are defined as: ![]() to ensure optimal treatment of affected infants through early diagnosis. to allow couples to embark on having a family knowing that they may avoid the birth of seriously affected children through selective abortion. to allow the widest possible range of informed choice to women and couples at risk of having children with an abnormality. In CVS chorionic tissue obtained via endoscopic biopsy is used to make the types of fetal diagnoses by culture of amniotic fluid cells The objectives of genetic screening developed by the Royal College of Physicians (London) are: of amniotic fluid at 12 weeks, although successful culture before this time is currently less reliable. Using standard cytogenetic techniques it is possible to culture amniotic fluid cells from as little as 10 ml. The test is carried out either by amniosentesis or by Chorionic Villus Sampling (CVS) at 14-16 weeks and 8-9 weeks respectively. Genetic Screening The sensitivity and the specificity of genetic screening is fairly high. Biochemical screening tests are used to identify those women who are at high enough risk to justify the hazards and costs of the diagnostic procedures.Ģ. This can detect about 60% of pregnancies with Down's Syndrome, about 90% of pregnancies with open spina bifida, and virtually all cases of anencephaly. ![]() Biochemical Screening In this technique, a single specimen of blood taken from a pregnant women at about 16-18 weeks of pregnancy, can be used to screen for Down's Syndrome and open neural-tube defects. Three different types of ANS methods are widely used ġ. Īlthough the screening test is not usually in itself diagnostic, it detects a subgroup of those tested who are at higher risk of having the disease or disorder than the original population screened, in many cases it is possible to make diagnoses with considerable accuracy. While the Danish Health Council considers screening as a community-based form of help based on the obligation to help the weak, the Nuffield Council on Bioethics (in Britain) points out that, although the primary aim seems to be to improve the health of persons suffering from genetic disorders, the benefits should include enabling individuals to take account of the information for their own lives, and empowering them as prospective parents to make informed choices about having children. Population screening for carriers of common recessively inherited diseases.ĭifferent health authorities in different countries have pointed out various aspects of ANS. Screening for sporadic conditions affecting the fetus (infections, chromosomal disorders, malformations, maternal diabetes) ģ. In the Dutch Health Council report on genetic screening, the major aim is defined as: "To enable people to decide upon a course of action that is acceptable for them". Although there is only a slight difference between the two procedures, the authorities do distinguish between antenatal screening (ANS) and antenatal diagnosis (AND).ĪNS services are based on population screening to identify people with a genetic risk, or a risk of having a child with a congenital or genetic disorder. It has been said that, probably around 90% of women in the UK have undergone one of these at some time during pregnancy. And, at the present time, antenatal screening and diagnostic techniques are almost the norm. Although antenatal diagnostic techniques were initially described in the nineteenth century, it was not until the middle of 20th century that the techniques were applied to AND and management of various genetic disorders and congenital malformations. When it was noticed that more than a quarter of all deaths in the first year of life were due to fetal abnormalities, scientists were alarmed and parents sought a 'remedy' for the 'problem'. Recent studies have indicated that the major paediatric health problems are handicaps due to genetic disorder or congenital malformation. Finally, with particular reference to some relevant concepts like 'responsibility', 'suffering' and 'interest', I attempt to describe the whole issue more comprehensively. Thirdly, since counselling is an integral part of ANT, I shall try to determine what the ideal of counselling before and after ANT is meant to be. Secondly, I will discuss the risks and complications of ANT, the concerns, doubts and moral controversies it raises. I shall discuss the procedures involved in ANT from different perspectives, beginning with definitions of 'antenatal screening' and 'antenatal diagnosis', the main objectives and indications for their use. ![]() Antenatal testing (ANT) is widely used in modern obstetrics and gynaecology.
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