Ethical Aspects of Screening for Down's Syndrome

Question 1

Outline the maternal age risk associated with Down’s syndrome.

Answer 1

Maternal age risk:

• 1:1600 under 25
• 1:340 at 35
• 1:40 at 43

Question 2

What % of Down’s syndrome pregnancies result in foetal loss?

Answer 2

• High foetal loss rate.
• 43% in first trimester.
• Still birth rate is 1-2%.
• Nearly half of all diagnosis still at live birth.

Question 3

What is the incidence of Down’s syndrome in the UK?

Answer 3

• Incidence approx 1:1000 live births currently in UK.

Question 4

What is the natural prevalence of Down’s syndrome?

Answer 4

• Natural prevalence is approximately 1:600.

Question 5

What are the characteristic physical features of Down’s syndrome?

Answer 5

Face:

• Epicanthic folds
• Mongoloid slant
• Brushfield spots

Head:

• Microcephaly
• Brachycephaly
• 3rd fontanelle

Ears:

• Small
• Simple

Hands:

• Short metacarpals and phalanges
• Clinodactyly
• Single palmar crease

Feet:
- Sandal gap

Hypotonia

Small size

Question 6

Why do we need to specifically consider the health needs of children with Down’s syndrome?

Answer 6

• Congenital abnormalities are more common in children Down’s syndrome.
• Acquired medical problems are more likely.
• Learning disability may make it less likely for individual to complain of symptoms.
• Some symptoms assumed to be part of the syndrome and left untreated.
• There are problems that are more likely to occur in people with down syndrome in every bodily system.

Question 7

What can a doctor do in promoting the health and well being of individuals with Down’s syndrome?

Answer 7

1) . Screen for likely medical problems.
2) . Make appropriate diagnosis of medical problems that arise.
3) . Treat treatable problems.
4) . Manage symptoms for all other problems.
- Role as a paediatrician to ensure that no one suffers unnecessarily from treatable symptoms or fails to reach their potential because of treatable medical problems.

Question 8

What problems should we be on the look out for in Down’s syndrome patients throughout the newborn period?

Answer 8

• Congenital heart disease.
• GI problems.
• Cataracts.
• Transient Abnormal Myelopeisis.
• Prolonged Jaundice.
• Poor feeding.
• Slow weight gain.

Question 9

What does the Down’s syndrome medical interest group do?

Answer 9

• The DSMIG is an organisation of health professionals interested in promoting the health and wellbeing of people with Down’s syndrome.
• The DMIG has written a list of basic medical surveillance essentials for people with Down’s syndrome. This is what they think that every child living in the UK should expect to be screened for.

Question 10

Describe congenital heart disease in children with Down’s syndrome.

Answer 10

• 40-50% of children with heart disease will have a congenital heart disease.
  1) . Atrio-Ventricular Septal Defect (AVSD) - occurs in 30-40% of people with Down’s syndrome. In the general population this condition is very uncommon. 80% of individuals with an AVSD will have Down’s syndrome.

AVSD is where there is a whole between the two sides of the heart between both the atria and the ventricles and in the middle area. Rather than having a discrete circulation on each side with a valve on each side there is a single valve in all four chambers. As a result of this blood coming into the left side of the heart does go through to the right ventricle normally and does go to the lungs normally and then passes back into the left side of the heart. However, because the left side of the heart is at higher pressure some of the blood just goes through the holes and back into the right side. Therefore, this blood that’s now partially oxygenated is mixed in the right side of the heart and there is an increased circulation through the lungs which causes increased pulmonary pressure. The increased pulmonary pressure is what causes the problem because it eventually rises so high that the shunt reverses and there is back pressure into the right side of the heart such that blood then goes into the left side of the heart and bypasses the lungs.

2) . Ventricular Septal Defect (VSD) - 20-30%
3) . Valve defects - 10-15%
4) . Patent Ductus Arteriosus - 5-10%
5) . Tetralogy of Fallot - 5%

Question 11

What is AVSD? What treatment should be given?

Answer 11

Atrio-Ventricular Septal Defect (AVSD) - occurs in 30-40% of people with Down’s syndrome. In the general population this condition is very uncommon. 80% of individuals with an AVSD will have Down’s syndrome.

AVSD is where there is a whole between the two sides of the heart between both the atria and the ventricles and in the middle area. Rather than having a discrete circulation on each side with a valve on each side there is a single valve in all four chambers. As a result of this blood coming into the left side of the heart does go through to the right ventricle normally and does go to the lungs normally and then passes back into the left side of the heart. However, because the left side of the heart is at higher pressure some of the blood just goes through the holes and back into the right side. Therefore, this blood that’s now partially oxygenated is mixed in the right side of the heart and there is an increased circulation through the lungs which causes increased pulmonary pressure. The increased pulmonary pressure is what causes the problem because it eventually rises so high that the shunt reverses and there is back pressure into the right side of the heart such that blood then goes into the left side of the heart and bypasses the lungs.

This condition needs treatment. Without treatment end up with a reverse shunt in the heart whereby the blood ends up missing the lungs and therefore they can no longer pass oxygenated blood around the body.

AVSD needs treatment early and there are many reasons why we need to specially consider individuals with Down’s syndrome.

AVSD is quite complex and quite difficult to treat but we need to consider the individual’s right to full treatment.

Without surgery AVSD will lead to increasing disability and early death.

In Down’s syndrome complications tend to occur earlier - pulmonary hypertension.

There is evidence for a better outcome if surgery is performed in the first 4 months of life.

Question 12

How can we screen for AVSD?

Answer 12

• In a newborn baby there are often no signs or symptoms of AVSD - may not be able to tell on examination.
• Examination would leave approximately 39% of DS patients with AVSD undiagnosed.
• Chest X-ray would leave about 30% undiagnosed.
• ECG would leave about 17% undiagnosed.
• Chest X-ray + ECG would leave approximately 15% of cases undiagnosed.
• The basic tests and examinations in a newborn baby will therefore not pick up the diagnosis of AVSD in all cases and therefore it is very important that we actually perform CARDIAC SCANS on newborn babies with DS.
• Cardiac scans have now become universal.
• Neonatal echocardiography is the most effective single diagnostic procedure. Must be carried out by an appropriately trained person and even then it’s not foolproof.

Question 13

Outline the DSMIG guidelines for cardiac surveillance.

Answer 13

Diagnostic Key Points:

• Child examination alone is insufficient.
• Chest X-ray is not useful for diagnosing AVSD.
• ECG - may be useful with superior QRS axis in AVSD.
• Neonatal echocardiography - most effective single diagnostic procedure.
• Neonatal echocardiography must be carried out by an appropriately trained person.
• Not foolproof even with experts.
• The cardiac status of every child must be established by the age of 6 weeks.
• All babies must have neonatal paediatric examination + ECG.
• If clinical or ECG abnormalities refer for ECHO and expert assessment by 2 weeks.
• If no clinical or ECG abnormalities refer for ECHO and expert assessment by 6 weeks.
• Continue clinical vigilance.

Guidelines also cover what to do if there is a late diagnosis of DS / if individuals have mover from other countries and haven’t had cardiac investigations:

• Late Diagnosis - immediate ECG and clinical examination then accelerated referral for ECHO and expert assessment.
• Pre-natal diagnosis - follow neonatal pathway.
• Older children with no previous ECHO - if no symptoms or signs + normal ECG then routine referral. If symptoms and/or signs + ECG changes then urgent referral.

In all cases an agreed screening protocol needs to be in place.

Question 14

In addition to cardiac problems in Down’s syndrome individuals, what is the other major classification of problems we need to look for during the newborn period? Describe some of the defects included in this classification.

Answer 14

Gastrointestinal Problems:

• About 10% of all babies with DS will have a GI problem.
• The commonest of these is duodenal or jejunal atresia - i.e. there is a discontinuity in the small bowel.
• Tracheoesophageal fistula - where there is a connection between the trachea and the oesophagus.
• Anal atresia - anal opening is either not formed at all or is smaller than it should be.
• Problems such as Hirschprungs disease and Gastroesophageal reflux occur with less frequency.
• Some of these (the top ones) can show up as abnormal images on a 20 week foetal USS. Some of these defects may be spotted as the first indication of Down’s syndrome. Quite common that we see our antenatal diagnosis having been picked up in this way.

Question 15

What are the most prominent health issues associated with Down’s syndrome in childhood?

Answer 15

Health Issues in childhood:

• Hearing
• Vision
• Still may have GI problems such as reflux, constipation
• Coeliac disease
• Obstructive sleep apnoea
• Infections
• Epilepsy - infantile spasms
• Autoimmune disorders including diabetes, thyroid disorder, vitiligo and alopecia
• Haematological disorders
• Cervical spine instability

Question 16

Describe hearing problems in people with Down’s syndrome. What different types of hearing problem are common? Why are they important? What are the treatments available?

Answer 16

• More individuals with DS will have a hearing problem at some point in their life than won’t.
• Common problem > 50% conductive hearing loss - i.e. their hearing is impaired because of fluid in the middle ear (glue ear).
• Only about 20% sensorineural - i.e. only about 1 in 5 people with DS will have a problem with nerve deafness. However, the nerve deafness is related with ageing and as we go through life about half of adults with DS will eventually have a hearing loss (55% adults).
• Hearing is particularly important for people who are likely to have language development problems and learning disability.
• We known from having looked at the cognitive profiles of people with DS that they have difficulties with processing auditory information over and above that which you would expect for their IQ, and over and above what you would expect for their hearing - i.e. slower than they should be at processing information from sound. Thus it is important that they can hear as well as possible to try and get over that.
• If you have hearing loss and a learning disability it kind of gives you a “double handicap” and it can lead to social isolation which is often a problem for socially handicapped people.
• There are medical treatments for glue ear including using anti contestants, antibiotics and possibly using acetylcysteine - no hard evidence of any working. Can also have surgical treatments - gromets are a good treatment for conductive hearing loss but doesn’t work well in DS (59% have complications, average of 3 re-dos of operation). Often just bypass the problem and give people with DS and hearing problems hearing aids. This works fairly well and is non-invasive.

Question 17

Describe eye problems in people with Down’s syndrome. What different types of eye problem are common? Why are they important? What are the treatments available?

Answer 17

Eye problems in Down’s syndrome:

• In addition to ear problems. eye problems are the other problem that is most likely to affect children with Down’s syndrome.
• Cataracts may present in newborns with DS and they would always be looked for in the newborn examination.
• Squints are common.
• Refractive errors occur in at least 60% of children with DS by age 7 - long sightedness, short sightedness and astigmatism and can be corrected with glasses.
• Throughout life people with DS are more at risk of some rare disease of the cornea known as keratoconus affecting about 5%.
• Blepharitis is so common in DS that almost everyone with DS has it - this is where you get crusting of the eyelids and dry skin around the eyelashes.

Question 18

Describe hypothyroidism in people with Down’s syndrome.

Answer 18

• Hypothyroidism is an example of an endocrine problem with an autoimmune cause.
• Hypothyroidism occurs in people with DS of all ages. It is most common in older people with DS. By school leaving at least 10% of the population will have an under active thyroid and this increases through middle age.
• In early childhood it is not terribly common in DS individuals but it is much more common than in the general population. What is a rare condition in ordinary children is a rare condition in children with DS and so we screen for it.
• If you have hypothyroidism we would normally expect you to have symptoms. In the general population we would expect to pick it up because of the symptoms i.e. it’s a clinical diagnosis.
• Classical signs may not be useful however because they overlap with DS - e.g. sluggishness, feeling the cold, dry skin, sparse hair, constipation, deafness, hoarse voice, complaints of aches and pains. For this reason it is really important to screen for hypothyroidism in people with DS otherwise it is likely to be missed.
• Hypothyroidism should be considered in any person whose mental or physical health or general affect has changed without explanation. Particularly consider cognitive slowing, loss of interest, physical slowing.
• Blood tests are performed regularly in people with DS just to check that their thyroid gland is still functioning well and that should continue throughout life. This is particularly important in adult life because hypothyroidism in DS may be confused with depression and/or dementia.

Question 19

Describe how growth in people with Down’s syndrome is different from the general population.

Answer 19

• Growth in people with Down’s syndrome is different from the general population.
• There has been a lot of interest in this and there was a question as to whether they may have growth hormone deficiency and therefore should be treated with growth hormone - they do not have GH deficiency although it is possible that their growth hormones work differently in DS and research is ongoing.
• The majority of poor growth in people with DS is because it is just part of the phenotype - however, it may also be a symptom of their other problems such as heart disease, thyroid problems, upper airway obstruction. It may be because they have feeding difficulties. In the past many people with DS were institutionalised and poor growth in adults with DS may be due to past neglect to an extent.
• Healthy children with DS are still smaller than the general population. The mean birth weight is 2.9kg (3.4kg in normal UK pop). During childhood they will fall behind their peers with their growth such that by the age off 3 years their height and weight are less than 2.5 sd below the height and weight in the general population. During childhood they have slow growth velocity and they seem to have periods of no growth (no growth periods seem to be more frequent and last longer in the DS population). When people with DS get to adolescence they do have a pubertal growth spurt but it possibly is less vigorous than it is in the general population. By the time they finish growing the mean height in DS is 157cm (5’1”) for males and 146cm (4’9”) for females.

Question 20

What health problems are seen in adults with Down’s syndrome?

Answer 20

Many of the problems from childhood still remain in adults with DS.

• Hearing
• Thyroid
• Autoimmune disorders - become more common
• Mental health problems
• Fertility
• Dementia - possibly not that more people with DS get dementia, just that they get it earlier
• DECREASE in incidence of solid tumours
• DECREASE in cardiovascular risk

Average live expectancy in DS individuals is now around 60.

Question 21

What heart disease problems are we likely to be faced with in adults with Down’s syndrome?

Answer 21

• In adults with DS we are still faced with heart disease problems even though they don’t have the congenital heart disease issues.
• We are faced with people who have had congenital heart disease which was corrected in the neonatal period and the longterm effects of that.
• We also know that people with DS are more likely to get minor problems with their valves = acquired valvular heart disease.

Question 22

Describe the sexual health problems that may be of concern in adults with Down’s syndrome.

Answer 22

• Women with DS do go through puberty like other girls. The mean age for this is very similar to the general pop. but there are females with DS who have very early or very late puberty also. They are likely to have menstrual disorders just like the general pop = PMT etc. this may be more difficult for them to deal with because of them not understanding and needing help managing their periods themselves. The menopause also occurs in DS but occurs earlier than in the general population.
• Important to think about the sexuality of people with DS. People with DS may well have sexual feelings and may well want relationships and this needs to be tackled.
• Fertility - most people have historically assumed that people with DS are infertile - men with DW as a population are in general very infertile and there are only 2 or 3 cases in the literature that have been proven of men with DS fathering children. However, still recommend the use of contraception because we cannot know for sure that they are not fertile - we just don’t really understand enough about it. Women with DS are less fertile than the general population but it is thought that about half of them probably are fertile. Therefore issues to do with contraception if they don’t want to have children, or considering their ability to be parents if they do, are extremely important.

Question 23

Describe the issue of mental health in individuals with Down’s syndrome.

Answer 23

• More of an issue in adults.
• People with DS are more prone to have depression, dementia, stress related mental health issues.
• May well struggle with understanding bereavement.
• May have mental health issues associated with their medical conditions.

Question 24

How can we ensure that people with Down’s syndrome get appropriate medical intervention?

Answer 24

• We can give info and training for professionals - one thing that DSMIG try to do.
• Can give info for parents, carers and people with DS themselves, something that DS associations are very active in.
• Can produce guidelines.
• Can provide specialist services.

Question 25

Describe how people with Down’s syndrome differ from the general population in their development.

Answer 25

• Developmental delay is almost universally part of DS. However the range of abilities we see in people with DS vary from severe LD to mild LD. The majority of people with DS will fall somewhere in the middle.
• Development largely follows the same lines as the normal population but is slower.
• There are particular issues in particular areas including in speech development, auditory processing, hypotonia leading to motor delay.
• The majority of individuals with DS will go to mainstream schools.

Question 26

Describe the general abilities of adults with Down’s syndrome.

Answer 26

Majority can:

• Make needs known
• Normal mobility
• Continent
• Independent from personal care
• Form lasting relationships

Many can:

• Read and write
• Get jobs
• Live semi independently

Some:

• Marry
• Have children

Some function at a high level:

• Performing arts
• Competitive sports

Question 27

Describe the social issues associated with Down’s syndrome.

Answer 27

• The natural incidence of DS is rising as age of child bearing increases.
• Birth incidence in UK is static despite screening and majority of affected foetuses are terminated.
• Parents of people with DS getting older.
• Life expectancy of people with DS is increasing rapidly.

Challenge to health and social care to meet the needs of an increasing older population of people with DS.

Question 28

Outline the challenges to society in providing for growing older population of people with Down’s syndrome.

Answer 28

We have growing cohort of older people with DS and we need to do lots of things including:

• effective and knowledgeable health services
• early diagnosis of physical difficulties
• opportunities for further education
• employment prospects
• effective adult community living environments
• leisure and recreation opportunities appropriate to age
• opportunities for adult friendship, partnership and marriage
• dealing with challenges of retirement
• life planning, which includes the individual with Down syndrome in decision-making
• formal and legal recognition of a selected carer if the parent(s)
are no longer able to fulfil this role; issues of trusteeship and guardianship need to be taken into account
• support in order to draw up a suitable will; this includes wills of the parent(s) and the person with Down syndrome
• adequate support services to help people with Down syndrome and to manage grief

Question 29

Outline the justifications for screening for DS.

Answer 29

• Down syndrome almost inevitably leads to significant learning disability
• Susceptible to a whole range of medical problems, greater than in general population
• People with the syndrome likely to need support throughout life
• Less likely to make economic contribution to society
• Considerable additional cost to society in terms of education, health and social care
• Currently in UK Majority of women opt into screening
• Confirmed antenatal diagnosis of Down syndrome approx 90% elect to terminate
• Screening / early diagnosis allow termination early in pregnancy

Question 30

Outline the issues relating to Down syndrome screening.

Answer 30

ISSUES RELATING TO THE SCREENING ITSELF:

• Public( and professional) understanding of what
risk screening means

• False positives - lead to invasive tests and loss of unaffected foetus( 2 for every 3 babies with Down
syndrome) = Parental anxiety

• False negatives - Reassures women who may have otherwise - considered invasive testing. Influences adjustment in women who do have an
affected baby

ISSUES TO CONSIDER:

• Women feeling under pressure to take up screening
• Screen positive women feel under pressure to go for invasive testing
• Women with confirmed diagnosis feeling under pressure to terminate pregnancy
• Earlier screening , with higher detection rates will lead to more procedures in pregnancies that would have terminated anyway

ISSUES TO CONSIDER FOR THOSE WHO GO ON TO HAVE A BABY WITH DOWNS SYNDROME:

• Perception that a life with Down syndrome is less valid
• Need to justify themselves
• Feeling “ judged” that they have willingly burdened themselves/the child/society
• amount of research effort and resource that go into screening in comparison to that spent on improving care for people with Down syndrome!

Question 31

Does antenatal screening help for people who would not consider termination at all?

Answer 31

• Prepares parents
– Time to adjust to new situation
– opportunity to find out information about Down syndrome
– Share information with friend and relatives

• Prompts additional scanning for anomalies more common in Down syndrome
• May influence time, place and mode of delivery