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Abortion time limits

A briefing paper from the BMA
May 2005

Part two - Factors influencing views on abortion time limits
Diagnosing fetal abnormality
Some form of prenatal screening is offered routinely to every pregnant woman in the UK in order to identify those at high risk of having an affected child, so that prenatal testing for the disorder may be offered. Screening may include maternal serum screening and ultrasound. Although ultrasound scanning is undertaken primarily to monitor the development of the fetus, it can also detect both major and minor defects and so may, in itself, offer a diagnosis as well as identifying those at high risk for whom further enquiries are necessary. A finding of potential abnormalities on serum screening, or soft markers at ultrasound (such as choroid plexus cyst, nuchal pad, head shape, short femur or talipes) or a calculation of risk of a chromosomal abnormality greater than 1:250, leads to the offer of further testing in order to achieve a definitive diagnosis.

The objectives of prenatal screening and testing for fetal abnormality include the identification of:

• Anomalies that are not compatible with life
• Anomalies associated with high morbidity and long-term disability
• Fetal conditions with the potential for intrauterine therapy
• Fetal conditions that will require postnatal investigation or treatment. [Go to reference 68]

In the past, some health professionals restricted access to prenatal diagnosis to those individuals who planned to terminate an affected pregnancy [Go to reference 69] but this approach is now widely regarded as paternalistic and unacceptable. The termination of an affected pregnancy is one, but not the only, possible outcome of prenatal diagnosis. For many people, prenatal diagnosis brings reassurance but, for those who receive an unfavourable result there can be practical benefits of having advance warning of the child’s disability, such as early access to care and treatment and allowing the family time to come to terms with the child’s disability. Some women will, however, opt to terminate an affected pregnancy.

Written information should be provided to all women giving details of the nature and purpose of the screening proposed, the procedure used, details of detection rates for defined common conditions, the meaning of a positive and negative screening result, and possible actions to be taken if a normal or abnormal result is obtained. [Go to reference 70]. Based on this information, women should be free to opt into, or out of, any form of prenatal screening. The option of having no screening at all should be offered as a reasonable and acceptable way forward.

Prenatal screening
What screening is offered?
Prenatal screening and testing has developed in an ad hoc fashion and despite attempts to standardise its availability, provision still varies across the UK. In June 2003, the Government made a commitment in Our Inheritance, Our Future that by 2004/05 all pregnant women in England would be offered antenatal screening for Down syndrome and by the end of 2004 antenatal screening for sickle cell and thalassaemia would be offered to women in high prevalence areas in England. [Go to reference 71] In October 2003, the National Institute for Clinical Excellence (NICE) published a clinical guideline on antenatal care setting out the standards that should be met in England and Wales. In terms of screening for fetal anomalies, NICE recommends that: [Go to reference 72]

• Pregnant women should be offered an ultrasound scan to screen for structural anomalies, ideally between 18 and 20 weeks’ gestation, by an appropriately trained sonographer and with equipment of an appropriate standard as outlined by the National Screening Committee.
• Pregnant women should be offered screening for Down syndrome with a test which provides the current standard of detection rate above 60% and a false-positive rate of less than 5%.
• By April 2007, pregnant women should be offered screening for Down syndrome with a test which provides a detection rate above 75% and a false-positive rate of less than 3%.

In August 2004 NHS Quality Improvement Scotland (NHSQIS) published for consultation draft clinical standards for pregnancy and newborn screening in Scotland. [Go to reference 73] This recommended that all women should be offered:

• Screening for Down syndrome at 11-14 weeks or 15-20 weeks
• Screening for neural tube defects at 10-14 weeks or 15-20 weeks
• A fetal anomaly scan at 18-20 weeks’ gestation.

Screening for structural anomalies
An early ultrasound scan is offered to most pregnant women, usually between 10 and 13 weeks’ gestation. This is to date the pregnancy and to detect multiple pregnancies. Occasionally some gross abnormalities will show up at this stage but this is not intended as a fetal anomaly scan. In some hospitals the nuchal translucency at the back of the baby’s head is measured at this scan and a risk calculated for Down syndrome (see below).

The main fetal anomaly scan takes place at between 18 and 20 weeks’ gestation during which the fetus is examined for congenital abnormalities. Although not all hospitals follow a standard checklist for this scan, the RCOG has devised a minimum standard which is set out below. The RCOG has recommended that an “optimal” scan should also include additional features to improve the detection of cardiac anomalies and facial cleft defects. [Go to reference 7] NICE has recommended that all units in England and Wales should aspire to this “optimal” scan, whilst recognising that not all units are able to afford the additional scanning time or scans required to achieve this goal at the present time. [Go to reference 75].

Minimum standards for the 20 week anomaly scan, recommended by the RCOG [Go to reference 7]

• Head shape and size and internal structures (cavum pellucidum, cerebellum, ventricular size at atrium < 10 mm)
• Spine: longitudinal and transverse
• Abdominal shape and content at level of stomach
• Abdominal shape and content at level of kidneys and umbilicus
• Renal pelvis < 5 mm anterior-posterior measurement
• Longitudinal axis abdominal-thoracic appearance (diaphragm and bladder)
• Thorax at level of a four-chamber cardiac view
• Arms: three bones and hand (not counting fingers)
• Legs: three bones and foot (not counting toes)

Some conditions, such as anencephaly, can be diagnosed at the 18-20 week anomaly scan but, in other cases, further testing is required in order to obtain a definitive diagnosis. This may be obtained by a more detailed ultrasound scan, at a specialist centre if necessary, and/or by amniocentesis (see below).

The detection of fetal anomalies by ultrasound
Although a detailed anatomy check is undertaken, detection of structural anomalies will never be 100%. Detection rates vary depending upon the type of anomaly (detection rates range from 76% for anomalies of the central nervous system to 17% of cardiac defects [Go to reference 77], the gestational age at scanning, the skill of the operator, the quality of the equipment used and the time allocated for the scan.

In July 2004, 3D/4D ultrasound images of developing fetuses were publicised. The images appeared to show fetuses smiling, waving and walking in the womb (read more here). Some of the media reporting of these images erroneously implied that they reflected a significant development in the earlier detection of fetal abnormality. This led to calls for a review of the Abortion Act with a view to limiting the timescale within which abortion for fetal abnormality may lawfully be undertaken. It is important that any decisions about such matters should be based on good quality and factual information. The most up-to-date and sophisticated scanning equipment can provide excellent images of the fetus and this may affect the way in which some people perceive the fetus and its moral status (read more here on moral status of the fetus and read more here on fetal viability). It is not the case, however, that the development of these scans has significantly changed the situation regarding the timing of diagnosis of fetal abnormality.

Both the RCOG and NICE recommend that the most appropriate time to undertake the anomaly scan is 18-20 weeks. This is based on the stage at which, in most cases, the organs/structures will be sufficiently developed to make a reasonable assessment. For this reason, even though clearer images may be available earlier of some organs/structures, this would not justify moving to earlier anomaly scans. For example, the vermis of the cerebellum is present at 15 weeks in 54% of cases but is not present in 100% of cases until around 19 weeks. Therefore if the anomaly scan was to be undertaken at 15 weeks, there would be a large number of cases which do not have the vermis of the cerebellum but in most of those this would simply mean that it has not developed yet rather than that it is absent.

It is also important to recognise that the detection rates of abnormalities are dependent upon, amongst other factors, the quality of the equipment used. Whilst all units should aim to meet the minimum standards for the quality of ultrasound scanning equipment set out by the RCOG, [Go to reference 78] the type of sophisticated equipment that was used to produce these 3D/4D images will not routinely be available in antenatal units throughout the UK.

Screening for fetal abnormality
Maternal serum screening can take place in the first or second trimester of pregnancy and may be combined with nuchal translucency measurement (for Down syndrome) by ultrasound.

Current methods of screening include:
11-14 weeks

• Nuchal translucency (NT) measured by ultrasound
• The combined test (nuchal translucency plus testing for maternal serum markers, human chorionic gonadotrophin (hCG) and pregnancy-associated plasma protein A (PAPP-A)

14-20 weeks

• The triple test (testing for hCG, alphafetoprotein (AFP) and unconjugated oestriol (uE3)
• The quadruple test (testing for hCG, AFP, uE3 and dimeric inhibin A)

11-14 and 14-20 weeks

• The integrated test (NT and PAPP-A at 11-14 weeks followed by the quadruple test at 14-20 weeks)
• The serum integrated test (PAPP-A at 11-14 weeks followed by the quadruple test at 14-20 weeks).

In relation to screening for Down syndrome, the information obtained from these tests is combined with the woman’s age and gestation of the fetus and a computer algorithm calculates the likelihood of an affected pregnancy. Women who are identified as being at high risk of having a child with Down syndrome (greater than 1:250) will usually be offered pre-natal testing for the condition by the culture and analysis of fetal cells (see below). The AFP test can also help identify fetuses with neural tube defects (such as anencephaly or spina bifida) or other severe anomalies such as kidney or abdominal wall defects, oesophageal or duodenal atresia or Turner’s syndrome.

Prenatal testing
Women who are identified as being at high risk of having a child with a disability – whether as a result of screening (see above), family history, having had a previous affected pregnancy or from genetic carrier testing – are usually offered diagnostic testing for a confirmed diagnosis. These tests require invasive procedures – usually amniocentesis or chorionic villus sampling (CVS) – to collect fetal cells for analysis; both of these procedures involve a risk of miscarriage. The lowest level of risk is associated with amniocentesis undertaken after 15 weeks’ gestation; the highest level of risk is associated with CVS when undertaken during either the first or second trimester. [Go to reference 79] Despite these risks, uptake of diagnostic testing after a high-risk screening result for Down syndrome is high, ranging from 43% to 77% (depending upon the magnitude of the risk). [Go to reference 80] Between 1996 and 1999, 94% of women with a positive diagnosis of Down syndrome opted to terminate the pregnancy. [Go to reference 81].

When are fetal abnormalities diagnosed?
A diagnosis of fetal abnormality may be made at any stage of gestation:

• some gross structural abnormalities will be evident at the initial ultrasound scan at 10-13 weeks;
• results of CVS may be available from 11 weeks onwards, with initial results available a few days later;
• amniocentesis may be undertaken from 15 weeks’ gestation, with the results available either within 48 hours or within 2-3 weeks depending on the technique used;
• further testing – such as amniocentesis – may be required for those classified as high-risk following second trimester (14-20 weeks) screening for Down syndrome;
• further testing – such as amniocentesis – may be required for those classified as high-risk following second trimester (14-20 weeks) maternal serum screening;
• information obtained from the structural anomaly scan may provide a diagnosis at around 18-20 weeks;
• further testing – such as amniocentesis – may be required to follow up soft markers identified at the anomaly scan at around 18-20 weeks;
• further monitoring and investigation or scanning may be required if a potential problem is identified at the anomaly scan;
• some conditions do not become evident until after 20 weeks, in particular cardiac defects which are best diagnosed at 24 weeks, microcephaly, which may not develop until after 20 weeks’ gestation and some hydrocephalus associated with intra-cerebral bleeds or infections which may not occur until 30 weeks’ gestation. Conditions such as these may not be evident until a non-routine scan is undertaken some time after 20 weeks, for example, because a problem has been identified with the pregnancy.

Decision-making following prenatal diagnosis
In some cases the disability diagnosed will meet the legal criteria for a termination of pregnancy (see below) and some women may wish to consider that option. At whatever stage fetal abnormality is diagnosed, women and their partners need good quality information about the implications of the result and the options open to them. Women will then need time and support to allow them to come to terms with the situation before deciding how to proceed. The vast majority of these pregnancies will be wanted and the decision of whether to terminate a pregnancy in such circumstances is never easy. The fact that parents decide to terminate an affected pregnancy does not mean that they do not experience an intense sense of loss and bereavement.

Very little research has been undertaken into the way parents make decisions following the diagnosis of severe fetal abnormality. This is partly because of the relatively small number of patients involved but also because of the inherent difficulty of obtaining valid consent and parents’ active co-operation at what is inevitably a time of great distress. As such there is very little information available about how women are counselled following diagnosis, what information and support they receive and how this affects the type and quality of decisions made. [Go to reference 82] In a review of the research evidence available, however, Helen Statham reports that parents frequently speak of feeling 'numb' and 'deeply shocked' when given the information. She says: 'Once a diagnosis has been made, parents experience deep shock at the loss of what they had believed previously was a normal pregnancy, whatever the abnormality and whatever the decision they subsequently make. In shock, and experiencing symptoms of acute grief including anger, despair, guilt, inadequacy, sleeping and eating difficulties they have no choice but to make decisions about the management and outcome of the pregnancy.' [Go to reference 83]

Whilst many of the studies conducted have yielded disparate results, all research data available reinforce the difficulty for parents of deciding how to proceed in the face of a diagnosis of severe fetal abnormality. The two factors that parents report as being most important to them in making a decision are:

1. the impact of the abnormality on the child, on themselves and on other immediate family members (including those not yet born) and
2. their prior attitudes and beliefs about abortion. [Go to reference 84]

In terms of the severity of the abnormality, parents tends to focus less on quantifying risk and weighing up the various options in any mathematical sense and more on their perception of their own ability to cope. [Go to reference 85] This judgment is made more difficult by the frequent lack of clear information about how severely the child will be affected. With many conditions, such as Down syndrome, there is a fairly wide spectrum of disability; parents are required to make a decision with no way of knowing for sure how severely their own child will be affected.

Summarising the findings of studies that have attempted to quantify women’s responses following termination for pregnancy for fetal abnormality, Statham and her colleagues report that:

• psychological distress is high in the immediate aftermath of termination of pregnancy with 40% of participants showing symptoms of psychiatric morbidity;
• this distress falls over time for most women;
• the nature and course of women’s psychological distress following termination of pregnancy for fetal abnormality is similar to that following spontaneous perinatal loss. [Go to reference 86]

The Abortion Act and fetal abnormality
'Serious handicap'
Section 1(1)(d) of the Abortion Act 1967, as amended, permits the termination of pregnancy where two doctors are of the opinion formed in good faith that:

“there is a substantial risk that if the child were born it would suffer from such physical or mental abnormalities as to be seriously handicapped”.

The Act does not give any guidance about how “serious handicap” should be defined and nor have the courts given any guidance as to how this phrase should be interpreted. The RCOG has listed a number of factors that should be taken into consideration when assessing individual cases. These are:

• the probability of effective treatment, either in utero or after birth;
• the probable degree of self-awareness and of ability to communicate with others;
• the suffering that would be experienced;
• the extent to which actions essential for health that normal individuals perform unaided would have to be provided by others;
• the probability of being able to live alone and to be self-supporting as an adult. [Go to reference 87]

The BMA’s guidance lists the following factors:

• the probability of effective treatment, either in utero or after birth;
• the probable potential for self-awareness and potential ability to communicate with others;
• the suffering that would be experienced by the child when born or by the people caring for the child. [Go to reference 88]

The question of how 'serious handicap' should be defined was raised in the courts in 2003 when the Reverend Joanna Jepson sought a judicial review of the decision of the Chief Constable of West Mercia Constabulary not to pursue a prosecution of doctors who terminated a pregnancy at more than 24 weeks’ gestation, where the fetus had been diagnosed with bilateral cleft lip and palate. The police authorities had undertaken an investigation of the case and were satisfied that 'the abortion was due to a bi-lateral cleft palate and was legally justified and procedurally correctly carried out'. [Go to reference 89] Rev Jepson challenged this decision on the basis that bi-lateral cleft lip and palate was not a 'serious handicap' and therefore the abortion had been unlawful. After hearing the application Lord Justice Rose and Mr Justice Jackson held that the case raised serious issues of law and issues of public importance and so granted permission for a judicial review. Subsequent to that decision the police re-investigated the case and sent a file to the Crown Prosecution Service (CPS). The CPS announced in March 2005 that the doctors involved would not face prosecution. The Chief Crown Prosecutor for West Mercia CPS, Jim England, said that the doctors had decided in good faith that a substantial risk existed that the child would be seriously handicapped if born. [Go to reference 90] In April 2005 it was reported that Rev Jepson was planning to revive her judicial review proceedings. [Go to reference 91]

Termination of pregnancy on grounds of fetal abnormalities
During 2003, a total of 1,941 abortions were carried out in England and Wales for fetal abnormality (ground E); this represents 1% of the total abortions performed in that year. [Go to reference 92] As can be seen from Tables 8 and 10 in Appendix 1, the number of terminations under ground E has remained fairly static over the last 10 years. A reduction in the amount of data published about terminations for fetal abnormality during 2003 makes it difficult to provide much analysis of these cases. More information is available, however, from the published data for 2002 and 2001.

Abortions on grounds of fetal abnormality
	2002 [Go to reference 93]			2001 [Go to reference 94]
Total	1,894			1,722
			24+ weeks’ gestation			24+ weeks’ gestation
Of which:
Congenital malformation	889	100.00%	79	777	100.00%	63
Malformations of the nervous system	411	46.23%		411	52.90%
Anencephaly	140	15.75%		148	19.05%
Other	338	38.02%		218	28.06%
Chromosomal abnormalities	707	100.00%	25	591	100.00%	24
Down syndrome	382	54.03%		347	58.71%
Other	325	45.97%		244	41.29%
Other conditions	281	100.00%	10	285	100.00%	13
Maternal factors	124	44.13%		89	31.23%
Other	157	55.87%		196	68.77%

Factors that can delay abortion for fetal abnormality
The majority of terminations for fetal abnormality during 2001 took place from 13 to 19 weeks’ gestation. Of a total of 1,722 abortions performed in 2001 for fetal abnormality in England and Wales (residents):

• 2.6% were performed at under 9 weeks
• 14.2% were performed at 9-12 weeks
• 48.6% were performed at 13-19 weeks
• 28.8% were performed at 20-24 weeks
• 5.8% were performed at more than 24 weeks. [Go to reference 95]

Data on terminations for fetal abnormality by gestational age are not available for 2002 and 2003. The most common factor affecting the timing of abortion for fetal abnormality is the timing of diagnosis. Many fetal abnormalities are not diagnosed until the latter part of the second trimester. Even when tests are available earlier in pregnancy, some women do not present for antenatal care until late in their pregnancy, delaying the timing of diagnosis. After a diagnosis has been made, women may need more information and more time to make a decision about how to proceed. Some women may at first choose to continue with the pregnancy but later, after more consideration or after seeking more information, change their minds.

A 1987 paper produced jointly by the BMA, Royal College of Obstetricians and Gynaecologists (RCOG), Royal College of General Practitioners (RCGP), Royal College of Midwives (RCM), British Paediatric Association and the Clinical Genetics Society considering the advantages and disadvantages of imposing an 18 week gestational age limit on legal abortion stated that late diagnosis of malformation was inevitable in some pregnancies. It went on to say 'it would be inhumane to these mothers, their babies and families to insist on the continuation of a pregnancy when the fetus was known to be seriously abnormal'. [Go to reference 95]