Marfan syndrome (MFS) was first described by the French doctor Bernard JA Marfan in 1896. It is a hereditary autosomal dominant disorder of connective tissue and affects collagen and elastin in many parts of the body, including the musculoskeletal, cardiovascular, respiratory, ocular and integumentary systems (Keane and Pyeritz, 2008).
The Marfan Foundation (2018) states that the incidence of MFS in the UK population is approximately 18 000, with 200 new cases diagnosed every year in the UK and worldwide, statistics show that 1 in 3 300 are affected by MFS with about 50% of sufferers remaining undiagnosed.
MFS is caused by a mutation in the gene for fibrillin-1 on chromosome 15. There are more than >1 000 mutations and each one is unique to an individual or family (Keane and Pyeritz, 2008). If one parent has MFS, there is a 50% risk of the fetus inheriting the mutant gene (Robson and Waugh, 2013). Gambling et al (2008) suggest that 25% of diagnosed cases arise as new mutations. Further research would be beneficial, as the correlation between the genotype-phenotype of MFS is unclear due to the large number of unique mutations.
There are a multitude of signs and symptoms of MFS. A patient with the condition can present as tall, with a thin physique, very little subcutaneous fat and with an excessive length of long bones, long fingers and toes (Robson and Waugh, 2013). Swan (2006) suggests that while both men and women are affected by the condition equally, it may appear more difficult to diagnose women because their appearance is less exaggerated than men. This could lead to a plethora of complications if the woman was to enter pregnancy undiagnosed, as many symptoms of cardiac disease are similar to those of pregnancy.
Associated general complications of MFS are increased joint pain and possible dislocations due to the laxity of joints (Kumar and Clarke, 2016). Additionally, those with MFS may encounter hernias, fatigue and scoliosis of the spine, leading to restrictions with mobility. Spontaneous pneumothorax may be experienced in more than 10% of those with MFS.
The most severe complications of MFS are cardiac. The main concern is the progressive enlargement of the aortic root diameter. The measurement of the aortic root diameter is of great importance during pregnancy as Brooke et al (2008) suggest, because progressive enlargement of the aortic root can lead to aortic dissection, which accounts for 20% of maternal cardiac fatalities. A normal aorta root diameter is 20–35 mm, but it is essential there is an early diagnosis of the condition so there is medical management within a detailed care plan. It is crucial women with MFS receive regular echocardiography, multidisciplinary assessment and discussions regarding lifestyle choices, such as healthy eating, exercise and smoking cessation, and these are addressed during pre-conception care, so the woman has achieved optimal health before embarking on pregnancy (Robson and Waugh, 2013). Pre-conception counselling and advice regarding treatments should be considered, so women are aware of the risks posed to her and her baby during the pregnancy, specifically as use of beta-blockers are advised throughout pregnancy to reduce aortic root dilatation (Marfan Foundation, 2018). The management of MFS patients should require a genetic counselling before conception, therefore with most trusts it would form part of pre-conception counselling.
Pregnancy booking
The role of the midwife in relation to cardiac disease in pregnancy is of the upmost importance. The midwife must be aware of signs and symptoms related to cardiac problems throughout the pregnancy, and make referrals to other professionals within a multidisciplinary team as quickly and as effectively as possible without delay.
Women who present at booking with a known cardiac problem must be considered high risk and have shared care with the midwife, obstetrician, cardiologist and anaesthetist (Wylie and Bryce, 2016). For women who present later in pregnancy with a suspected cardiac problem, diagnosis usually involves blood tests, an electrocardiogram, echocardiography and chest X-rays, all of which are considered safe in later pregnancy (Lewis and Drife, 2004). The role of the midwife is to take a comprehensive booking history and promptly make referrals to other health professionals.
Respiration and pulse must be monitored, as well as other vital observations, at each antenatal visit and women encouraged to take iron and vitamins to prevent anaemia which can place additional stress on the heart due to lower levels of circulating oxygen (Burrow et al, 2004).
Wylie and Bryce (2016) indicate the difficulty of recognising symptoms of cardiac problems in pregnancy, because pregnancy can produce ‘similar responses’ in the body. Therefore, the midwife must have full knowledge of the woman's baseline observations so possible complications unrelated to pregnancy can be identified.
The New York Heart Association (NYHA) classification was developed to identify the extent of heart failure (Table 1). The categories are based on the woman's limitations during physical activity and her symptoms, including breathing, shortness of breath, angina pain and palpitations (Gambling et al, 2008). NYHA class is a useful tool which can be used by midwives to assist in identifying the degree of strain on the heart due to the additional workload during pregnancy.
| Classification | Patient characteristics |
|---|---|
| Class I: No objective evidence of cardiovascular disease | Patients with cardiac disease but without resulting limitation of physical activity. Ordinary physical activity in the patient does not cause fatigue, palpitation, dyspnoea or angina |
| Class II: Objective evidence of minimal cardiovascular disease | Patients with cardiac disease resulting in slight limitation of physical activity. The patient is comfortable at rest. Ordinary physical activity results in fatigue, palpitation, dyspnoea or angina |
| Class III: Objective evidence of moderately severe cardiovascular disease | Patients with cardiac disease resulting in marked limitation of physical activity. They are comfortable at rest. Less than ordinary activity causes fatigue, palpitation, dyspnoea or angina |
| Class IV: Objective evidence of severe cardiovascular disease | Patients with cardiac disease resulting in an inability to carry on any physical without discomfort. Symptoms of heart failure or angina may be present even when the patient is at rest. If physical activity is undertaken, discomfort increases |
Pregnancy has a significant risk on the compromised heart. There are three periods during the childbearing process which are considered as critical (O'Brien and Walker, 2014). Between 28 and 32 weeks' gestation, haemodynamic changes reach a peak. There is a 50% increase in blood volume and this increases the workload of the heart, as do pregnancy hormones which cause connective tissue changes and an increase in uterine blood vessels. During labour there is an increase in cardiac output due to the physical stress of uterine contractions and psychological stress of labour pain; and finally 12–24 hours postpartum is considered a critical period as additional blood volume from the uterus and placental site return to the systemic circulation. Consequently, due to the increased cardiac output during these three critical periods, there is an increased risk of aortic dissection during pregnancy due to the additional stress placed on the aortic root. As noted by Fujitani and Baldisseri (2005), 50% of aortic dissections in women occur during pregnancy.
Although most women who present with cardiac disease can have a positive outcome of pregnancy according to Davis and Macnab (2016), in contrast Gambling et al (2008) suggest those women who have an aortic root of more than 40 mm should be advised against pregnancy irrespective of their NYHA class, as they are at greater risk of aortic dissection. An aortic root >40 mm carries a fatality rate of 36–72% within 48 hours, and without intervention such as surgery or beta-blocker therapy, death will occur within one week (Gambling et al, 2008).
To ensure a positive outcome for women with cardiac disease, pre-conception advice and a full physical examination are crucial, alongside a detailed care plan which is regularly evaluated and updated within a multidisciplinary team (Robson and Waugh, 2013).
Additional antenatal appointments should be arranged in consultation with the obstetrician, ideally where all professionals are available in one clinic in order to reduce the number of visits required, and advice given regarding adherence to prescribed drugs to avoid further complications (Kumar and Clark, 2016). A pre-delivery anaesthetic assessment is recommended, because women with MFS can experience potential airway management problems due to cervical spine instability and a high arched palate (Gambling et al, 2008).
Kumar and Clark (2016) note women should have regular echocardiograms at six-week intervals to identify any changes to the aortic root diameter. According to a single case report by Rosenblum et al (1983), even regular echocardiograms may fail to ‘predict’ aortic dissection in pregnancy for women with MFS. However, the reliability of this could now be questioned because advances in technology mean echocardiograms could be considered a good predictor of possible dissection (Burrow et al, 2004).
During the antenatal period, fetal growth will be regularly assessed by ultrasound, and an anomaly scan will be advised at 16–18 weeks gestation to detect for congenital abnormalities, because the risk of a cardiac defect is increased in these babies (Nanda et al, 2012). Furthermore, it is suggested the midwife should advise the woman of possible premature labour and ruptured membranes which is common in those who have MFS (Meijboom et al, 2006).
Mode of delivery and intrapartum care
It is vitally important, a plan of care is made well in advance regarding mode of delivery, timing and type of analgesia and anaesthesia, and these decisions should be made within the multidisciplinary team in discussion with the woman (Tan, 2010).
During labour and delivery, there are significant haemodynamic changes which occur with each uterine contraction. These can be tolerated by healthy women, but can result in morbidity and mortality for those with heart disease. There is a 300–500 ml transfer of blood back into the systemic circulation with each contraction. Alongside the anxiety of labour and the sympathetic response to pain, there is an increase in heart rate and blood pressure, increasing cardiac output by 34% during contractions and 12% between contractions. This can lead to greater stress on the enlarged aortic root, increasing the risk of aortic dissection (Meijboom et al, 2006). For this reason, it is important to examine the literature exploring vaginal delivery and caesarean section, to calculate the most appropriate method of delivery.
Langesaeter et al (2010) suggested a greater focus on caesarean section as preferred mode of delivery rather than vaginal delivery. Caesarean section can be advantageous in respect of date of delivery, and anaesthesia can be planned well in advance so further risk of damage or dissection to the aortic root can be avoided. However, it could be questioned for whom it is advantageous.
A Dutch study by Meijboom et al (2006) investigated the obstetric maternal outcome of pregnancy in women with MFS. Of the 122 women enrolled in the study, 31% had a caesarean section, compared to a rate of 11% in the general Dutch population. This raises the question of whether the decision for caesarean section was in the best interests of the woman, or if the high rate of caesarean reflects fear and caution for further complications by obstetricians and cardiologists. Furthermore, the study did not take NYHA class, into consideration. Wylie and Bryce (2016) suggest that women who are NYHA class I or II can often experience quick, uncomplicated labours, and as long as the woman is given adequate analgesia to minimise physiological and psychological stress, a vaginal delivery can be achieved.
Moreover, Meijboom et al (2006) suggest there are greater risks with a caesarean, such as fluctuations of blood pressure as a result of intubation and anaesthetic agent for those who require general anaesthetic; increased risk of wound and uterine infection, a greater risk of venous thromboembolism and increased blood loss compared with vaginal delivery.
A study by Langesaeter et al (2010) suggests caesarean section is the safest mode of delivery. They found that haemodynamic stability could be achieved by using regional anaesthesia, such as epidural, alongside use of intravenous oxytocin and invasive monitoring via an arterial line. Cardiac output is decreased, causing vasodilatation, which reduces venous resistance.
According to Richards and Yentis (2006), vaginal delivery is the safest mode of delivery because it causes less stress to the heart, but there are a number of considerations to be taken into account when a vaginal delivery is planned. During the first stage of labour, it is advisable for the woman to remain in an upright or left lateral position to prevent aortocaval compression by displacing the uterus away from the aorta and vena cava.
Most importantly, directed pushing during the second stage of labour must not be encouraged because this causes a decrease, and sometimes a complete loss, in cardiac output that cannot be restored (Richards and Yentis, 2006). Robson and Waugh (2013) could be criticised for suggesting directed pushing during the second stage of labour, because they fail to question the consequences of the stress it would place upon the heart. This could lead to aortic dissection, which accounts for 20% of maternal cardiac fatalities (Swan, 2006). Furthermore, Robson and Waugh (2013) fail to provide evidence to support their recommendation of directed pushing in relation to women with cardiac disease.
It is important to note, some women may require an assisted vaginal delivery. Meijboom et al (2006) suggest vacuum or forceps be used, so long as effective analgesia such as epidural was utilised early in labour, because this would minimise physiological stress and outweigh the risk compared with caesarean section.
Following analysis of a range of literature in support of both vaginal delivery and caesarean section, it could be argued the most appropriate mode of delivery is vaginal delivery with spontaneous pushing and the aid of instrumental delivery, if required, as the risks associated with this outweigh any risk associated with caesarean section.
There does not seem to be a definite appropriate method as most of the research and articles contradicted one another. This indicates the decision needs to be made in relation to individual circumstances, in discussion with the woman.
It is important to highlight that women with cardiac disease must always give birth in an obstetric unit where all professionals within the multidisciplinary team are available. Close monitoring of vital signs is crucial, and echocardiography should be used throughout labour with someone who can interpret the findings at hand. Oxygen therapy should be available if required, as well as close monitoring of fluid balance through the use of a central venous pressure catheter if necessary (Roberts and Ketchell, 2012).
How can midwives support women?
Caring for women with cardiac disease in pregnancy can be considered outside the parameters of the midwife and a need for referral to other practitioners is essential. The midwife will continue to give care as part of the team and will need to be aware of any cardiac compromise throughout pregnancy and childbirth (NMC, 2018).
Within midwifery practice, women-centred care remains paramount, so midwives should encourage a two-way transfer of knowledge and information at each contact. This builds a trusting relationship with the woman, and enables midwives to organise a plan of care based on the information they have. It is essential to gradually drip-feed new information to the woman, so she is able to acquire the knowledge to empower her to make decisions about her own care, and allow her to prepare for critical periods during pregnancy and childbirth.
According to West and Turner (2018), uncertainty can cause stress and anxiety. By examining communication theories, in particular the uncertainty reduction theory in seminal literature by Berger (1979), it can be understood that good communication is the foundation of how midwives can support women with heart disease. ‘One of the motivations underpinning interpersonal communication is the acquisition of information with which to reduce uncertainty’ (Heath and Bryant, 2013). Thus, it is vital midwives discuss all options concerning care with women and include them in decision making; they act as an advocate for them, and offer information so they can make an informed decision. They also need to prepare them for the possible need of hospital care in the third trimester.
It can be difficult to normalise pregnancy for women with heart disease without labelling them. Therefore, it is important the woman is invited to parent craft classes alongside other pregnant women so she feels included, regardless of whether she may have already discussed health promotion issues with another professional involved in her care.
Conclusion
A multidisciplinary approach is essential for successful management of pregnant women with cardiovascular disease. The midwife must be aware of the signs and symptoms of CHD to help identify women who are unaware they have a cardiac problem and make immediate referrals to other professionals. The NYHA classification system is a useful tool which can be used by midwives to inform practice by alerting them to any additional stress which is placed on the heart.
Women-centred care is essential within midwifery practice. By sharing knowledge and information of MFS with the woman, midwives and other healthcare professionals are able to organise a plan of care through joint decision-making, which in turn will empower her and prepare her for critical periods during pregnancy and childbirth. In general, vaginal delivery with epidural analgesia is the preferred mode of delivery because there are fewer risks than caesarean section and haemodynamic stability can be achieved.
Moreover, by examining communication theories such as the uncertainty reduction theory, it was found good communication is the foundation of the support midwives can give to women who have cardiovascular problems in pregnancy. By inviting these women to sessions such as parent craft to discuss health promotion as a larger group, it may help a woman with cardiac disease feel included, therefore attempting to normalise her pregnancy.