Critical care decisions in fetal and neonatal medicine: ethical issues
Clinical perspectives
Decisions about when to deliver a fetus
4.3 In parallel with advances in the detection of fetal abnormalities, there has been an improvement in identification of cases where the fetus is at high risk of dying in the womb or where early delivery is needed for other reasons. Early delivery may be necessary for the health of the pregnant woman because of intense bleeding, the development of complications of pregnancy which threaten her life, or because the fetus will be at risk if left in the womb. Decisions need to be made about which treatments should be given and when the baby should be delivered. However, the options for effective treatment with medicine or surgery are limited (see paragraphs 4.10–4.11). In addition, extreme prematurity creates its own problems (see Chapter 5).
4.4 The most common causes of premature birth are spontaneous preterm labour, preterm pre-labour rupture of membranes, and multiple pregnancy (see Table4.1). Approximately 15–25% of premature births occur when a baby needs to be delivered early because of maternal or fetal complications during pregnancy.8 The most frequent complications are maternal hypertensive disorders such as pre-eclampsia, which can put both the woman and fetus at risk, and where the fetus is failing to grow in utero(fetal growth restriction) and showing signs of distress. The balance between the risk for the fetus of remaining in the womb and the risk of death and disability after premature delivery needs careful assessment.
4.5 When a pregnant woman is at risk of an imminent premature delivery, evidence from several clinical trials shows that a single course of steroids can help to prepare the fetal lungs for
| Table 4.1: Causes of premature birth in Europe and North America | |
| Causes of prematrue delivery | Frequency |
| Spontaneous preterm labour | 31-50% |
| Multiple pregnancy and associated complications | 12-28% |
| Preterm labour rupture of membranes | 6-40% |
| Hypersensitive disorders of pregnancy | 12% |
| Intrauterine growth restriction | 2-4% |
| Antepartum haemorrhage | 6-9% |
| Miscellaneous - cervical | 8-9% |
| Incompetence, uterine malformation | |
| Source: These date are reprinted from Slattery MM and Morrison JJ (2002) Preterm delivery Lancet360: 1489-97, with permission from Elsevier. The data are based on a number of studies in Europe and North America. The frequencies quoted indicate the proportion of premature births associated with each of the caused listed | |
birth while causing no identifiable problems.The treatment helps to mimic the effects that occur naturally prior to delivery near full term. Steroids used in this way can reduce the risk of a premature baby dying, developing lung disease or brain injury, particularly if birth takes place 24 hours or more after a course of the medicine has been given.
4.6 A second intervention is to delay or arrest the onset of labour. The inhibition of contractions may be achieved by a variety of treatments. Delaying labour can benefit the fetus by allowing time for steroid treatment to be completed or for the woman to be transferred to a specialist hospital before she gives birth.10However, some women experience adverse effects from medicines used to delay labour, and randomised trials have not demonstrated a clear benefit from their use.11 Furthermore there is always the concern that delaying premature delivery could worsen the health of the woman and fetus if there is an underlying reason for the premature labour such as an infection or high blood pressure.12 For example, chorioamnionitis, a bacterial infection of the two membranes of the placenta and the fluid around the baby, can lead to more serious maternal and fetal infections and increase the risk of other problems in the baby.
4.7 A better understanding of fetal health has been achieved with improved antenatal assessment. Fetal growth restriction is often caused by problems with the flow of blood through the placenta, resulting in insufficient nutrients reaching the fetus. Techniques that identify poor fetal growth and condition have improved markedly. Growth may be monitored, usually by standard and Doppler ultrasound imaging, and by recording fetal heart rhythms. A decision about early delivery is needed when there are clear signs that growth restriction is affecting fetal function, detected for example by changes in fetal behaviour, abnormal blood flow or a worsening heart trace. By the time that it is clear that the fetus will die, it may be too late to save the baby’s life. Yet delivery beforehand, when there are only early signs of fetal compromise, may expose the baby to the complications of prematurity. The decision to deliver is finely balanced and different obstetricians faced with the same clinical situation may make different judgements.
4.8 A recent trial randomly assigned pregnant women to early delivery or to deferred delivery if there was good evidence that a fetus was failing to thrive, as well as uncertainty over the best course of management (the Growth Restriction Intervention Trial, GRIT).13The results showed that the overall death rates for fetuses or babies were not substantially different in the two groups. Early delivery produced more deaths on the neonatal unit whereas deferred delivery led to more deaths before birth. There were no differences in outcomes for survivors at two years of age.14
4.9 Dilemmas arise in the clinical management of multiple pregnancy (see paragraph 3.4) where there are significant complications or evidence that the health of one or more fetuses is being adversely affected. This may be because of an underlying abnormality, fetal growth restriction or brain injury. These complications may lead to spontaneous prematurity, and increased risks of malformation and cerebral palsy, the risks rising as the number of fetuses increases. The options for clinical management include treatment, where possible, or early delivery. Selective reduction of multiple pregnancy by feticide is sometimes advised by doctors when the health of one or more fetuses is compromised.
Possibilities for fetal treatment15
4.10 A pregnant woman’s options are usually limited when a condition affecting the health of the fetus(es) is identified through screening, as effective fetal treatments are available for only a small number of conditions. They include:
Ultrasound-guided procedures to obtain fetal blood samples or tissue to confirm diagnoses, or to give treatments such as transfusions.
Fetal blood transfusion if a fetus suffers from rhesus haemolytic disease, which can cause heart failure, the accumulation of fluid (hydrops), and eventual death. Transfusing blood that is compatible with the pregnant woman’s blood group into the fetus can reverse the process and allow the pregnancy to progress normally.
Laser treatment by fetoscopy to correct a condition that occurs in identical twins where connections develop between the two fetal circulation systems through the placenta.16
Drainage tubes used to remove fluid that accumulates in unwanted places, especially around the fetal lungs or when the outflow of urine is blocked in the bladder. The tubes drain the accumulated fluid into the amniotic sac around the fetus. This procedure is simple to carry out and can allow the fetus to develop normally. The dilemma for doctors is whether the condition leading to the problem is reversible, or whether the damage done by the accumulating fluid, for example to the growth of the lung or kidney, is already too far advanced for the procedure to benefit the fetus.
Medicines given to a pregnant woman often cross the placenta and can be used to treat the fetus. For example, the use of digoxin or flecainide can be highly effective in preventing abnormal fetal cardiac rhythms. Untreated, this condition may be fatal. However, care must be taken to treat the fetus without producing unacceptable side effects in either the fetus or the woman.
Possibilities for fetal surgery
4.11 Open surgical operations to correct or lessen the impact of abnormalities of the fetus before birth are rare, although a number of attempts have been made over the past 20 years to repair conditions such as congenital diaphragmatic hernia or spina bifida.17Procedures of this kind, which involve opening the pregnant woman’s abdomen and uterus under general anaesthesia and partly exposing and operating on the fetus, must be considered experimental. Because the risks for the pregnant woman are high and the outcomes reported to date have been generally poor or worse than operations performed after birth, there are currently only a small number of centres in the USA that undertake open fetal surgery. Consistent with the recommendations of the Bristol inquiry,18 the view of the Working Party is that new procedures in fetal surgery should be offered in the UK only within a protocol approved by a research ethics committee (REC).
4.12 If there are no options for surgery or other treatments to treat a fetus with a serious abnormality, a woman faces a stark choice of whether to continue with her pregnancy or seek termination. For some conditions detected by testing, the outcome will be certain; examples would include anencephaly or renal agenesis. Doctors would be able to explain what is wrong with the fetus and how the baby would be affected. In other cases the outcome may be much more difficult to predict. The woman may prefer to wait for results of further tests if these are available and to defer the decision about whether or not to have a termination. If no further tests are possible, she may decide to continue her pregnancy in the knowledge that there is a risk of miscarriage, stillbirth or having a baby with health problems or disabilities. Alternatively, she may decide to terminate her pregnancy.
Late termination of pregnancy
4.13 In England, Scotland and Wales the Abortion Act 1967 specifies that termination of pregnancy beyond 24 weeks of gestation is only legal if either a fetus is at substantial risk of serious handicap or there is a risk of grave permanent injury to the life, or the physical or mental health of the woman.19In England and Wales in 2004, 124 terminations were carried out after 24 weeks of gestation, out of a total of 185,415 (less than 0.1%).20Of these, 91 were for congenital malformations, 23 for chromosomal abnormalities and ten for other conditions, such as disorders related to gestation and growth. Some specialists in fetal medicine have reported that the absence of an absolute cut-off in law at 24 weeks has relieved the pressure for hurried decision making in a small number of patients where further investigations, consultation and/or monitoring are necessary to help establish a prognosis, or where there are delays in access to screening. While the Abortion Act 1967 does not apply to Northern Ireland, recent court cases have ruled that terminations may be permitted in some exceptional circumstances where a woman’s life or physical or mental wellbeing would be at risk.21 Fetal abnormality alone would not be a lawful ground for termination in Northern Ireland.
Footnotes
8 Tucker J and McGuire W (2004) Epidemiology of preterm birth Br Med J329: 675–78.
9 Roberts D and Dalziel S (2006) Antenatal corticosteroids for accelerating fetal lung maturation for women at risk of preterm birth The Cochrane Database of Systematic Reviews, Issue 3.
10 Royal College of Obstetricians and Gynaecologists (2002) Tocolytic Drugs for Women in Preterm Labour(London: RCOG), available at: http://www.rcog.org.uk/resources/Public/pdf/Tocolytic_Drugs_No1(B).pdf, accessed on: 3 Aug 2006.
11 Ibid.
12 Committee on Understanding Premature Birth and Assuring Health Outcomes (2006) Preterm Birth: Causes, consequences and prevention, Behrman RE and Stith Butler A (Editors) (Washington, DC: National Academies Press).
13 Thornton JG, Hornbuckle J, Vail A, Spiegelhalter DJ and Levene M; GRIT study group (2004) Infant wellbeing at 2 years of age in the Growth Restriction Intervention Trial (GRIT): multicentred randomised controlled trial Lancet364: 513–20.
14 Research in this area is continuing.
15 Medical terms in this section are explained further in the Glossary.
16 Blood may flow preferentially in one direction in such cases and one fetus may fail to grow properly while the other suffers the consequences of excess circulating blood, placing both fetuses at risk of dying before birth or of developing cerebral palsy if they survive what is often very premature birth. Randomised trials have shown that using laser therapy to divide the blood vessels causing the ‘twin-to-twin transfusion’ can be more successful in treating this condition than other treatments. However, long-term outcomes are variable. For a review, see Harkness UF and Crombleholme TM (2005) Twin-twin transfusion syndrome: where do we go from here? Semin Perinatol 29: 296–304.
17 A randomised clinical trial of fetal surgery for spina bifida is in progress in the USA. See US National Institutes of Health Management of Myelomeningocele Study (MOMS), available at: http://www.clinicaltrials.gov/show/NCT00060606, accessed on: 20 Sept 2006. Preliminary data from the UK have recently been published on fetal surgery to correct severe congenital diaphragmatic hernia[0]. See Deprest J, Gratacos E, Nicolaides KH; FETO Task Group (2004) fetoscopic tracheal occlusion (FETO) for severe congenital diaphragmatic hernia: evolution of a technique and preliminary results Ultrasound Obstet Gynecol 24: 121–6.
18 The Bristol Royal Infirmary Inquiry (2001) The Report of the Public Inquiry into Children’s Heart Surgery at the Bristol Royal Infirmary 1984–1995: Learning from Bristol, available at: http://www.bristol-inquiry.org.uk/final_report/the_report.pdf, accessed on: 25 Sept 2006. The recommendation made was that “Before any new and hitherto untried invasive clinical procedure can be undertaken for the first time, the clinician involved should have to satisfy the relevant local research ethics committee that the procedure is justified and it is in the patient’s interests to proceed. Each trust should have in place a system for ensuring that this process is complied with.” In the UK the Interventional Procedures Programme at the National Institute for Health and Clinical Excellence (NICE) is responsible for assessing and publishing guidance on the safety and efficacy of new interventions, including fetal ones, when they are first used in the NHS in England, Scotland or Wales outside of a REC-approved protocol. The Programme defines interventions as procedures “used for diagnosis or treatment that involve incision, puncture, entry into a body cavity or the use of ionising, electromagnetic or acoustic energy”. See: National Institute for Clinical Excellence (2004) The Interventional Procedures Programme – Programme manual (London: NICE).
19 Abortion Act 1967; Mason JK and Laurie GT (2005) Mason and McCall Smith’s Law and Medical Ethics, 7th Edition (Oxford: Oxford University Press). See also Chapter 8. Note that although the Abortion Act applies to Scotland, differences in the law in Scotland meant that the Act did not significantly alter existing policy.
20 Government Statistical Service (2005) Abortion Statistics, England and Wales: 2004, available at: http://www.dh.gov.uk/assetRoot/
04/11/75/74/04117574.pdf, accessed on: 13 June 2006. Note that these figures do not include 8,764 abortions performed on women who were not resident in England or Wales.
21 Mason JK and Laurie GT (2005) Mason and McCall Smith’s Law and Medical Ethics, 7th Edition (Oxford: Oxford University Press), p148.