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 of pregnancy?”

What risks will my idiopathic scoliosis present in pregnancy?

The short answer is that in most cases there will be few, if any, problems, but mothers-to-be who have the idiopathic scoliosis, understandably, have a lot of questions about the effect their scoliosis could have on them and their child.

These concerns can be about the health risks of pregnancy to the mother who has scoliosis and about whether they will have problems during the pregnancy or the birth due to their spinal curve. 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 in delivery. Naturally, parents also worry about the effect that becoming pregnant could have on their body in general and their spinal curve.

Breathing during pregnancy

Because 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, and apart from a mild degree of restricted lung capacity, young mothers will therefore 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 prove 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, such as 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 50% 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.

Evidence suggests, however, that as long as the vital capacity exceeds about 1 litre the outcome will probably be good. Indeed, recent successful pregnancies have been achieved in individuals with a vital capacity of about 600 millilitres (0.6 litre), provided that 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 also lead to heart strain in the mother but, 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 an early-onset scoliosis will be 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, however, 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 all the 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, this is not common, so parents can be reasonably reassured that the risk of the baby developing scoliosis is low. New parents will, however, naturally be concerned about this possibility.

There are exciting new developments in genetics and allow it is not yet possible to provide a screening test for scoliosis, science is working on ways to use genomic markers and clinical indices to spot scoliosis early.

Ultrasound scans of the baby will of course check overall growth, including spinal development. The exception to this are some of the congenital forms of scoliosis, which are associated with conditions such as neurofibromatosis, and with some types of myopathy and muscular dystrophy which cannot be detected via ultra-sound. These conditions are hereditary, and some of them can be detected in other ways, before the baby is born. Genetic counselling services exist in all regions of the UK and any individual with concerns can be referred for advice by their GP or hospital specialist.

Will the curve of my spine worsen during pregnancy?

Large hormonal changes occur during pregnancy, with an increase in oestrogen, progesterone. These hormones help to loosen 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 so it is no surprise that many pregnant women experience discomfort as a result of the strain put on their back. As the baby grows, the additional burden affects the mother’s posture and because the abdominal muscles stretch as the baby grows, they have to work hard to try to maintain good or ‘neutral’ posture. Consequently, additional strain is 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 indeed, 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 is necessary because the growing baby and the growing uterus puts an added strain on the mother’s breathing. Some pregnant woman with severe scoliosis can become uncomfortably short of breath, even with the help of non-invasive ventilation.

Will I have complications in labour or during the birth of my baby?

If you have scoliosis it is always sensible to discuss the management of labour in advance with the midwife, GP, 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.

Epidural pain relief may be able to be used during labour, however, epidural insertion can be challenging, particularly in women with severe scoliosis or in those who have had corrective surgery with metal rods and fusion. For these women it may be more difficult to locate the right place for the epidural anaesthetic to be injected into the spine. This may also mean that the epidural does nor spread evenly across the body. For some mothers with scoliosis, epidural insertion might not be possible and other options for pain relief during labour will be discussed at an early assessment with your obstetric anaesthetist. This allows the pain relief for labour to be individualised.

Will I need to have a Caesarean birth?

For some women with scoliosis, the baby may not lie head down, but instead it may lie transverse (across the abdomen) making a Caesarean birth necessary, or the severity of the mother’s scoliosis may make a Caesarean necessary. It is vital that women who know a Caesarean is a possibility have an early discussion with their obstetric anaesthetist about the most appropriate type of 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 survey, carried out by Dr Phillip Zorab and Dr David Siegler, of 118 pregnancies in 64 women with scoliosis found that no serious medical problems were encountered. 17% of mothers reported increased breathlessness and 21% had increased back pain but found it tolerable. A normal delivery was achieved in most women with only 17% requiring a caesarean section for obstetric reasons.

More recently in a study of 142 pregnancies in women who had been treated with corrective scoliosis surgery there was a slightly higher proportion who had a caesarean section compared with the general population, but the rates of complications in pregnancy and delivery were no higher than in the general population and the babies were born healthily. About 40% of mothers developed low back pain during pregnancy but this had resolved by 3 months after delivery in most. A survey of cases of mostly idiopathic scoliosis in India published in 2010 again shows a higher caesarean rate than in individuals without a scoliosis but there were no major problems with the mothers’ health.

These results justify an optimistic outlook for mothers with scoliosis. However, individuals with congenital or early-onset scoliosis, and those with muscle weakness, breathlessness before pregnancy, or heart problems, should always seek medical advice.

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. It is for this reason that the Royal Brompton, Queen Charlotte’s, Hammersmith and St Thomas’ Hospitals in London run a pre-pregnancy counselling service. Here, 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. In addition, the management of any coexisting problems such as asthma, hayfever, indigestion, or diabetes can be planned for, in order to support both mother and baby.

If you need help or advice please call our Helpline on 020 8964 1166 or email info@ssr.org.uk.