Coping with scoliosis while pregnant
Idiopathic scoliosis is fairly common in young girls, many of whom plan to have children at some point in their lives. The effects of scoliosis on the back, the pelvis, and in some cases the respiratory system, frequently prompt the question from a prospective parent: “What are the risks for women who have scoliosis in pregnancy?”
What risks will my idiopathic scoliosis present in pregnancy?
Most women will enjoy a straightforward pregnancy without any problems. However, mothers-to-be who have idiopathic scoliosis will have a lot of questions about how their condition might impact pregnancy and unborn child.
These concerns can be about the course of pregnancy and their baby’s birth due to their spinal curvature. Many prospective mothers are anxious that they could pass scoliosis on to their children, and whether the condition could pose a risk to carrying the child to term, or cause difficulties with delivery. Equally, expectant mothers can have anxieties about the effect the pregnancy could have on their body, in particular, worsening of the spinal curve.
Breathing during pregnancy
As the most common type of scoliosis is the idiopathic form, which develops around the age of 10–14 years, the growth of lungs and heart is complete. Apart from a mild degree of restricted lung capacity, young mothers will rarely encounter severe breathing problems during pregnancy or as they get older.
Some degree of breathlessness is common from the early months of pregnancy in all women. This shortness of breath is partly caused by the rise in progesterone, which stimulates breathing by increasing the depth of each breath. Blood volume also increases. These normal physiological changes are well tolerated and only likely to be a problem if the ‘vital capacity’ is low or heart function is compromised.
In some people who are born with congenital scoliosis, or in whom the scoliosis is associated with a neuromuscular condition (e.g. muscular dystrophy or poliomyelitis), lung size may be more severely restricted because the lungs haven’t had room to grow. Breathing will also be affected if the muscles that expand the rib cage are weak. A useful way to assess lung size is to measure ‘vital capacity’ with a simple blowing test. This measures the total amount of air that can be actively expelled from the lungs after taking in maximum breath. If this ‘vital capacity’ is less than 60% of what is predicted, a full review by a respiratory specialist is advisable, after which the oxygen levels to both mother and baby will be monitored carefully. The tests that the respiratory specialist might advise include an overnight sleep study.
Evidence suggests that as long as the vital capacity exceeds about 1 litre the outcome will probably be good. Recent successful pregnancies have been achieved in individuals with a vital capacity of about 600 millilitres (0.6 litre), if they received respiratory support. Below this lung size, problems with a reduction in oxygen level (hypoxaemia) can occur. Low oxygen levels characteristically worsen on exertion and during sleep and may be accompanied by a rise in the concentration of waste gas (carbon dioxide).
A low oxygen level is harmful to the growing baby and can sometimes lead to heart strain in the mother. Fortunately, this situation is rare, and monitoring of oxygen levels can be easily done during exercise and at night. In very few cases of mothers with severe scoliosis, respiratory support at night can be provided by a small breathing machine. This is called non-invasive ventilation. Non-invasive ventilation is needed only in a few patients, usually those with a vital capacity of less than 1 litre and/ or weak muscles. Provided that this breathing support is used and carefully monitored, successful outcomes for mother and baby can be achieved.
Sometimes early-onset scoliosis is associated with a congenital heart defect (e.g. a hole in the heart). Heart problems will nearly always be detected in childhood and corrected where necessary. To ensure that there are no heart problems, an ECG (electrocardiograph) and echocardiogram (an ultrasound scan) of the heart can be performed to check the heart for this complication, helping to gather more information needed to support mothers with a successful pregnancy and birth.
Provided that the oxygen level of the mother is fine and heart function is good, there should be no threat to the growth of the baby, allowing the enlarging uterus to easily adapt to the shape of the mother.
It is important to remember that most people with adolescent onset scoliosis will not have a low vital capacity or heart problems. Simple breathing tests can check on lung function and if there is any query about this your GP can refer you to a respiratory specialist.
Will my baby also have scoliosis?
Although idiopathic scoliosis sometimes runs in families, it is uncommon, so parents can be reasonably reassured that the risk of the baby developing scoliosis is low. New parents will be naturally concerned about this possibility.
There is exciting new research in genetics that in the future might provide an antenatal screening test for scoliosis.
The fetal anomaly scan undertaken at around 20 weeks will check the development of the baby’s spine. If you are advised you need scans after this time, they assess baby’s overall growth and are not able determine if there are any changes to the spine. Genetically inherited conditions such as neurofibromatosis, some types of myopathy and muscular dystrophy cannot be detected on routine antenatal screening and ultrasound scans. Some of these conditions can be detected in other ways, before the baby is born. If you are in a high-risk group for one of the above, you will be referred for genetic counselling.
Will the curve of my spine worsen during pregnancy?
Hormonal changes that occur during pregnancy increase the levels of oestrogen and progesterone. These hormones help loosen and relax the ligaments of the pelvis and lower spine to ease the birth of the baby. Although concerns have been raised that hormonal fluctuations could lead to progression of a spinal curvature, most studies are reassuring, suggesting that changes in the degree of the spinal curve are slight, provided that the curvature is stable at the outset of pregnancy.
Will my back pain worsen during pregnancy?
Around 80% of people will have some sort of back pain in their life, therefore it is no surprise that many pregnant women experience discomfort due to the strain put on their back by their pregnancy. As the baby grows, the additional burden affects the mother’s posture. As abdominal muscles stretch as the baby grows, there is increase in the core muscles work to maintain a neutral posture. This leads to additional strain placed on the muscles that run parallel to the spine. Keeping the core strong and maintaining a reasonable level of fitness will help to alleviate back pain in pregnancy for mothers with or without scoliosis.
Mothers with more severe scoliosis may need to have their babies early. This means having the baby at less than 37 weeks gestation. This might be necessary because the growing baby and womb puts an added strain on the mother’s breathing.
Will I have complications in labour or during the birth of my baby?
If you have scoliosis, it is sensible to discuss the management of labour in advance with the midwife, obstetrician and anaesthetist. This will help you and your healthcare team plan for a successful labour and birth.
The position of a mother’s body during labour and delivery is crucial for the comfort of her spine, and being in one position or being still for long periods of time is unhelpful and often uncomfortable. You will be encouraged to move around and if your baby requires continuous monitoring, this can be facilitated so that your movement is not restricted.
All pregnant women with scoliosis are referred for a review by an obstetric anaesthetist before their baby is due so that an individualised pain relief plan can be made. Epidural pain relief can be used during labour for all women with uncorrected scoliosis. However epidural insertion can be challenging, particularly in women with severe scoliosis. Your anaesthetist might choose to perform an ultrasound scan of your back to aid the insertion of the epidural. Those who have had corrective surgery with metal rods, the anaesthetist will need to review the imaging of your spine to look at the location of the rods and screws. For low lumbar metal work, the anaesthetist will offer alternative forms of pain relief in labour. This is to avoid complications such as failure to site an epidural, risk of headache due to scarring and risk of infection around the metal work.
Will I need to have a Caesarean birth?
For some women with scoliosis, there might be an obstetric reason for a Caesarean birth (e.g. a breech or transverse lie baby). Some women opt to have a Caesarean birth as it is their preferred choice of delivery. All women with scoliosis who are having a Caesarean birth will meet with the obstetric anaesthetist before their delivery to be informed about the most appropriate type of anaesthetic. Your anaesthetist might suggest a spinal or general anaesthetic.
How many women with scoliosis have successful pregnancies and births?
The good news is that it has been known for many years that the outcome of pregnancy in scoliosis is generally good. A vaginal birth is usually achieved in women with just a small proportion requiring a Caesarean birth for obstetric reasons.
Will there be any problems after my baby is born?
About 40% of mothers develop low back pain during pregnancy, but this usually resolves by 3 months after birth.
What advice could I get?
Pre-pregnancy counselling is an excellent idea for all people contemplating pregnancy and is especially relevant to those with scoliosis. Maternal medicine networks throughout the UK offer this service, therefore you can ask your GP for referral when contemplating pregnancy. During this appointment, the individuals’ scoliosis and the possible complications can be discussed in detail, and advice given about sensible health measures, vitamin and folate supplementation, posture and exercise.
If you need help or advice please call our Helpline on 020 8964 1166 or email info@ssr.org.uk.
