Patients presenting for ultrasound scanning expect the operator to perform a detailed examination to confirm fetal health. In the majority of cases the fetus is normal but unfortunately in about 2% of cases an abnormality is seen. The benefit of early diagnosis of fetal anomalies is that information can be provided to enable couples to consider various options and to allow appropriate plans to be made for treatment and follow up.

Outcome depends on the recognition of the potential severity of defects; these defects fall into four groups. In lethal conditions, such as anencephaly, the couple may wish to consider the options of terminating or continuing the pregnancy. In disorders that are not lethal but are associated with death, such as diaphragmatic hernia, planned delivery in a centre with appropriate neonatal intensive care facilities will optimise neonatal outcome. In abnormalities that are associated with childhood morbidity such as hydronephrosis, and which may lead to renal failure due to urinary tract infections, prenatal diagnosis provides the opportunity for early postnatal treatment. In the case of chromosomally abnormal fetuses where there is a risk of physical and mental handicap, the couple may wish to continue the pregnancy or undergo termination. Therefore, examining for increased nuchal translucency, which is associated with an increased risk for aneuploidy,² is an essential component of first trimester ultrasound assessment. Couples can consider invasive testing for karyotyping based on the discovery of a risk factor and also avail themselves of counselling about the implications of the chromosomal abnormality.

I was surprised by the author’s criticism of the ultrasound operator who performed a comprehensive fetal examination that included measuring nuchal translucency. I am sure that the sonographer, like all involved in prenatal care, believed that the aim of screening for Down’s syndrome is not about minimising the birth rate of the condition, but about optimising the position of the parents.³

Eustace, D L S (Wycombe General Hospital, High Wycombe, Buckinghamshire HP11 2TT).

Editor—Venn-Treloar is not alone in being concerned about screening for nuchal translucency being done without the consent of the mother.^1-1 The National Childbirth Trust reported that there are important differences in England and Wales in the information provided before screening, in the types of tests available, and in the amount of counselling provided before, during, and after such tests.^1-2

It is likely that these discrepancies result from the lack of any agreed screening policy in England and Wales. If screening is offered it should be done in an organised and closely supervised way. Counselling should be given before patients attend for any tests, and the information provided should be standardised and agreed between local obstetricians, midwives, and general practitioners. It should be made clear which tests are available and their limitations, and it should be emphasised that such tests are optional and will not be carried out without the prior consent of the patient.

The majority of women want to have an ultrasound scan early in their pregnancy to reassure them that their baby is alive and to confirm their dates. The term “first trimester scan” does not necessarily include screening for nuchal translucency. Data collected over two years at Queen Mary’s Hospital in Kent on 8000 scans done at 12 weeks’ gestation identified 251 incorrectly dated pregnancies, 164 cases of early pregnancy loss, 128 multiple pregnancies, and 15 chromosomal abnormalities. These data show that detection of chromosomal abnormalities is statistically the least valuable function of a scan at 12 weeks’ gestation.

Thus, the first trimester scan provides useful information and should not be looked on as a screening test for chromosomal abnormalities but as a foundation on which subsequent care during the pregnancy can be reliably based. The fact that it also provides an opportunity to screen for chromosomal abnormalities for those who wish it is an added benefit.

Occasionally the nuchal abnormality is so obvious that it can be seen without making a formal measurement. Since increased translucency may also be associated with other chromosomal abnormalities (including trisomy 13 and trisomy 18), cardiac abnormalities, and a number of genetic syndromes, this may create a dilemma for the ultrasound operator if a patient has declined nuchal assessment. The only way to minimise these types of problems is to ensure that the parents understand as fully as possible the purpose and limitations of tests before testing. This should include the use of well written explanatory leaflets and the provision of appropriate counselling by healthcare professionals.

Hampton, Katherine (10 Juniper Close, Tunbridge Wells, Kent TN4 9XS).

Editor—Venn-Treloar was correct to say in her Personal View that ultrasound scans are offered as a part of routine antenatal care and that most women are unaware that they can refuse the test.^2-1 In September 1996 I attended a symposium on antenatal screening organised by the Birth Control Trust. At the symposium doctors admitted that although the use of ultrasound scanning is almost universal formal consent is rarely sought. Most women are enthusiastic about having an ultrasound scan perhaps because they do not associate scans with screening as they might associate a blood test with screening.

I had an ultrasound scan during my first pregnancy in 1995, not realising that it could have been the first step towards pressure to have an abortion. I was grateful for this knowledge during my current pregnancy when I again opted to have an ultrasound scan at 19 weeks in order to see my baby and to reassure myself about his or her development; this time at least I was aware of the possibilities.

Nash, T G (36 Collington Avenue, Bexhill-on-Sea, East Sussex TN39 3 NE).

Editor—Venn-Treloar’s experience of having an ultrasound scan during her pregnancy clearly upset her but the bias in her view is obvious. As an obstetrician I sometimes have the feeling that some patients view their carers as people who are working against them rather than as people who want to help them. The trust previously established easily between doctors and patients is more difficult to achieve now. Some women do a lot of reading about pregnancy and probably attend antenatal classes run by groups outside the NHS. They develop ideas about the place of doctors in the management of pregnancy and this makes it more difficult to build a trusting relationship.

I think that Venn-Treloar is wrong when she says that many mothers attend for an ultrasound scan believing that the test is designed to confirm that the baby is well. The majority of mothers understand that ultrasound scanning is done to detect abnormalities and that excluding abnormalities confirms that the baby is well.

The patient expects to be informed about any abnormality identified as a result of the scan. If information is not given she would probably sue her obstetrician when it became known that the abnormality had been detected earlier. If an abnormality is detected health professionals have a duty to give full information about the management of the condition to the patient, even if one option is termination. If this is done properly the patient will be under no pressure to choose an option that is contrary to her beliefs. If she does not wish to have a termination that should be the end of the matter and support for alternative management should be given.

Patients do not give written consent before a consultation; they accept that the clinician will elicit symptoms and signs to make a proper diagnosis. Ultrasound scanning is an extension of the consultation which allows an image of the fetus to be viewed and clinical judgment used. Measurement has been part of clinical skill for a long time. By presenting themselves for consultation or ultrasound scanning patients indicate that they are willing to have the examination. To insist on written consent would slow the process considerably, often to the detriment of other patients.

I do not think that the deviousness Venn-Treloar attributes to her colleagues exists in practice. I hope her views will not prevent me or my colleagues from continuing to provide this service which has been demanded by patients themselves.

Layng, Johanna (Division of Primary Care and Population Health Sciences, Imperial College School of Medicine, Chelsea and Westminster Hospital, London SW10 9NHj.layng@cxwms.ac.uk).

Editor—Venn-Treloar highlights the existence of a problem that has become obvious to me in the short time I have been in general practice.^4-1 As a general practitioner registrar I worked in a practice in Berkshire at a time when screening for nuchal translucency had been recently introduced at the local hospital. I was aware that women were often inadequately counselled for this screening test. This prompted me to perform a questionnaire study. Questionnaires were posted to 96 women after screening; 68 (71%) were returned. Women were asked whether they felt they had been adequately prepared for the screening test and were also asked to rate how much they knew about Down’s syndrome on a scale of 1 (very little) to 10 (a lot). Altogether 42 (70%) out of 60 women felt they had not had adequate preparation for the test. Twenty four (39%) out of 62 women rated their knowledge of Down’s syndrome at 3 or less. Half of these women said they did not want to know more about the syndrome.

The provision of screening programmes raises many issues; one of these is who will provide the counselling.^4-2 Evidence suggests that health professionals often lack knowledge about the tests they offer and about the conditions being screened for, that they often underestimate how much information women need or want, and that they underestimate patients’ capacity to understand the information they are given.^4-2,4-3 Women who are not adequately counselled are anxious after positive results and are falsely reassured by negative results.^4-2

To date priority has been given to implementing the practicalities of testing and there has been little attention paid to the need for counselling.^4-4 It is time that this attitude was reviewed; counselling should be considered a necessary part of the implementation of any screening programme. Counselling will become increasingly important as we are able to detect more genetic abnormalities. Health professionals should be trained to provide counselling. Interested health professionals—such as midwives, obstetricians, and general practitioners—need to have access to funded training programmes to allow them to provide a service for which there will be an increasing demand.

Nicolaides, Kypros (Harris Birthright Research Centre for Fetal Medicine, Department of Obstetrics and Gynaecology, Kings College School of Medicine and Dentistry, London SE5 8RX).

Editor—I respect Venn-Treloar’s opposition to abortion for fetal abnormalities and her view that many families benefit from the richness of life that a baby with Down’s syndrome can bring.^5-1 However, I also respect the views of those parents who when faced with the prospect of having a child who would be severely handicapped choose to terminate the pregnancy.

Pregnant women are offered the option of having an ultrasound scan at 10-14 weeks’ gestation. This scan is used to accurately date the pregnancy, determine the presence of one or more fetuses (and whether the fetuses are alive or dead), diagnose major fetal abnormalities (for example, anencephaly, encephalocoele, holoprosencephaly, exomphalos, obstructive uropathy, sirenomelia, and amniotic band sequence), and measure the accumulation of subcutaneous fluid in the neck region. Increased nuchal translucency is associated with a high risk of chromosomal abnormalities, major defects of the heart and great arteries, severe diaphragmatic hernia, skeletal dysplasias, and a wide range of genetic syndromes. It is also associated with an increased risk of intrauterine death. Sonographers have the responsibility for examining the fetus and counselling the parents about their findings and the possible importance of such findings.

Increased nuchal translucency and maternal age can be analysed together to determine an estimate of the risk of Down’s syndrome. The parents can then be offered the option of having amniocentesis or chorionic villus sampling but they are informed that these invasive tests carry a 1% risk of miscarriage. The perception of the relative risk of a miscarriage compared with the risk of the birth of a baby with chromosomal abnormalities depends on the values and expectations of the parents. We must let parents decide whether to have invasive testing. Similarly, if the fetus is found to have a chromosomal abnormality it should be left to the parents to decide whether to have an abortion or to continue the pregnancy.

Cooper, Sally-Ann (Rockingham Forest NHS Trust, Kettering, Northamptonshire NN15 7PW).

Editor—Venn-Treloar’s Personal View on screening for nuchal translucency addresses the important issue of who is considered worthy of life by the medical profession.^6-1 Subjective value judgements should not play a role when decisions are made regarding the provision of clinical care. It is not possible to make an objective evaluation of who is worthy of life: having a lower IQ is merely one of many possible variables that might be considered. People with Down’s syndrome (and people with learning disabilities from other causes) play an important role in society. This often extends beyond the joy and love that they may bring to their own family. The extent to which a society can positively assimilate its most vulnerable members is surely proportional to the extent to which any decent individual would wish to belong to that society. The new eugenics movement is abhorrent and should not be encouraged by the medical profession.

Editorial by McFadyen et al