Management of Fetal Spina Bifida

Every person with spina bifida is unique, meaning there is a large variety of possible effects, from mild to severe. Generally, a defect higher up on the back is associated with more serious consequences. Ultrasound of your baby can be used to determine the height of the defect in the spinal column before they are born. This will give doctors information about what problems the child will likely have. Typically these problems will include weakness in the feet or legs and problems with bladder and bowel control. However it is not possible to predict before birth exactly how severe these problems will be. Sometimes other abnormalities are also found during the ultrasound scan. This combination increases the likelihood of an underlying genetic syndrome. A procedure to sample the amniotic fluid (amniocentesis) is recommended to exclude chromosomal problems (chromosomes are the carriers of genetic information inside each of our cells). If additional problems are confirmed, the outcome will depend on all abnormalites together. In the rest of this information we will only discuss what we call an isolated spina bifida aperta or isolated myelomeningocele. This means a baby with spina bifida aperta without other abnormalities.

Motor, sensory and orthopaedic problems
Normally, nerves from the spinal cord go to the muscles of the legs and feet to allow movement. In spina bifida, the spinal cord and nerves are often entirely or partially interrupted at the place of the lesion in the back. This can cause:
•    curvature of the spine (also called scoliosis)
•    muscle weakness in the legs
•    impaired balance
•    contracture (stiffness and tightening) of several joints
•    club feet (also called talipes).
For children with a very low lesion, they are expected to be able to stand and learn to walk or have only mild weakness or curvature in the feet. For lesions at progessively higher parts of the spine, children may have difficulties with walking, or may not be able to walk, stand or even sit.

Because nerve pathways are interrupted in spina bifida, there is less or no sensation in the skin served by nerves below the site of the lesion in the back. This can lead to pressure ulcers in the skin, or it can cause cold feet and lower legs.

Brain changes
The changes in the hindbrain, referred to as the Chiari II or Arnold-Chiari malformation do not necessarily lead to problems for the child, and will not usually require treatment. However, in severe cases children may have difficulty with swallowing    and    breathing.

Additionally brain fluid may continue to accumulate inside the ventricles, leading to ventriculomegaly. This occurs in about half to two thirds of babies with spina bifida. If untreated, hydrocephalus can cause damage to the brain due to increasing pressure.

When hydrocephalus occurs, surgeons often need to implant a shunt. This is a thin tube that drains the fluid from the brain into the abdominal cavity (tummy) of the child. The satisfactory working of the shunt will be assesed from time to time in the out patient clinic. Further surgery to a shunt may be required if there are problems such as infection or blockage. Such shunt complications can be responsible for long term disabilities. Hydrocephalus and complications of the drains may result in some learning and behavioural issues.
As many as two thirds of children with spina bifida have an IQ within the normal range. However, children with open spina bifida may have learning and behaviour issues. These include difficulties with concentration, attention and problem solving.

Bladder and bowel problems
Children with spina bifida often have problems controlling their bladder. This may cause urinary incontinence or inability to fully empty their bladder (referred to as urinary retention). This may lead to bladder and/or kidney infections. To prevent complications, medical staff may recommend that they empty their bladder using a small catheter through the urethra several times a day (called clean intermittent catheterisation). First the parents are taught this and later the children can learn to do it for themselves. Children also often have bowel issues, resulting in either incontinence or constipation. This can be helped by bowel wash-outs (irrigation) or medication.

Hormonal problems
Children with spina bifida often have a shorter stature than usual. Early puberty is more common, especially in cases of hydrocephalus.

Psychosocial and sexual problems
When young adults with spina bifida are asked about whether they feel happy, their response usually is very similar to their peers. Men with spina bifida may have decreased fertility, but medication usually helps with erection difficulties. Women with spina bifida may have reduced sensation which affects their full enjoyment of sex.

If this is your choice then your labour and the delivery will usually be medically induced. This is done in hospital. Medical staff will discuss the entire process with you beforehand. After delivery you will have time to spend with your child, and the opportunity to take photographs if you wish. Staff can arrange a cremation or burial, but that is not mandatory. Your doctor may suggest that you have additional testing (such as genetic or chromosome tests, or a postmortem of the baby) after delivery. This will depend on what exactly is seen on scans.

If this is your choice then you will be supported throughout your pregnancy. During the last three months of pregnancy, your child will be monitored by ultrasound, for instance to measure the amount of fluid in the brain of the baby. If the fluid increases, sometimes medical staff will recommend delivering your baby a bit earlier. The delivery should be done in a centre where a spina bifida medical team is available, so that your child can be taken care of by a specialist team. Some women can have a vaginal delivery without this damaging the baby’s spinal cord lesion.

During the first days of life, several specialists (including a paediatric neurologist, neurosurgeon, urologist or orthopedic surgeon) may examine your child. Medical staff may arrange a number of imaging tests, such as ultrasound or MRI (magnetic resonance imaging), in order to measure the effect of the spina bifida on the brain and the spinal cord. This information will help plan further management and predict the long-term outcome as accurately as possible. The team looking after your baby will include all kinds of specialists, such as a specialist nurse, paediatrician, social worker and paediatric physiotherapist.

An operation to close the defect is needed very soon after birth. The surgery is performed by a paediatric neurosurgeon, sometimes with a plastic surgeon. The surgeons will discuss the details of the operation with you beforehand. The operation usually takes less than two to three hours. Thereafter, the baby will be regularly checked, in particular to assess whether they may need a shunt.

Fetal surgery is where surgeons perform an operation on a baby whilst it is still in the womb, hence before it is born.

In open fetal surgery, the mother’s abdomen (tummy) and womb are opened and then the spinal defect is closed with stitches using a similar surgical technique to closure after birth. If the spinal defect is too big to be closed just by stitches then a surgical patch may be used as well as stitches. The womb is then closed and the baby continues to grow and develop in the womb until birth. In 2011, the results of an American study called the "MOMS trial" were published. The study investigated the effect of operating on babies with spina bifida whilst they were still in the womb as compared to operating on babies after birth.

Because of the benefits shown in that study, NHS England has commissioned two providers to provide this surgery, University College Hospitals London and University Hospitals Leuven, Belgium.

An alternative technique, called fetoscopic surgery, is now available at our units. This involves opening the mother’s abdomen and then narrow telescopic instruments are put into the womb via small holes. The womb is gently filled with warm moist air to allow the surgeons to operate. The baby’s spinal defect is then closed using stitches. If the spinal defect is too big to be closed just by stitches then a surgical patch may be used as well.

In the MOMS study mentioned above, there were 77 children with spina bifida who were operated on in pregnancy, while they were still in the womb. Their outcomes were compared to 80 babies who had spina bifida surgery after birth.

Children who were operated before birth had:

• Less severe Chiari II malformation (hindbrain herniation)
• Less need for a shunt for hydrocephalus by the age of one year, though the effect was less when the ventricles were already enlarged before the operation.
• Better leg function at 30 months of age

Follow up of the children in the MOMS study at five to 10 years of age have shown that children who had prenatal surgery were more likely to be able to walk and had better mobility skills.

Overview of the four-year outcomes from November 2019 to November 2023 for prenatal surgeries conducted across both Fetal Surgery Centers (FSCs):

• In total, 67 open fetal surgeries have been performed.
• Following surgery hindbrain herniation improved in most fetuses when assessed by 32 weeks of pregnancy.
• On average, babies were born just before 35 weeks of pregnancy.
• The outcomes, including the numbers of babies that died before or after birth, have been in line with the outcomes of the MOMS study. The deaths were not thought to be due to the fetal surgery.
• At birth there were no leaks of cerebrospinal fluid at the spina bifida repair site.
• At 1 year of age,all outcomes were in the expected range of babies with the condition.
• Out of 48 babies who are at least one year old, nearly 90% of babies had improvement in Chiari II malformation and 14 underwent shunting procedures.
• At 3 years of age most infants were able to walk independently or were using walking aids.
• For fetoscopic surgery, so far studies have shown the technique we are using has results for short term baby outcomes equivalent to those after open fetal surgery.
• At the moment we do not yet have long-term data on baby or child outcomes because this fetoscopic techique has been used for only a few years.

For fetoscopic surgery, so far studies have shown the technique we are using has results for short term baby outcomes equivalent to those after open fetal surgery. At the moment we do not yet have long-term data on baby or child outcomes because this fetoscopic techique has been used for only a few years.

If you are interested in fetal surgery for your baby, your doctor will discuss it with you and your partner.

Doctors will repeat the evaluation of your baby by ultrasound and MRI, before the decision can be made to proceed with surgery. This is to make sure that we know as much as possible about the condition that your baby has.

The fetal surgery operation should take place before 26 weeks of gestation. Fetal surgery is only considered when the lesion is open (this is the most common type of spina bifida), in a singleton pregnancy (i.e. not twins or triplets), and when we know that the chromosomes of the baby are normal.

The level of the lesion has to start at the thoracic or lumbar or upper sacral vertebrae, and there has to be hindbrain herniation (Chiari II malformation).

Surgery during pregnancy is not done in cases where one or more criteria are not met including:

• there are additional abnormalities with the baby (anatomical or chromosomal)
• there is an increased risk of premature birth (e.g. previous premature birth, shortened cervix)
• there is maternal obesity (BMI above 40)
• previous surgery on the womb (apart from caesarean section)
• there is a low-lying placenta.

You will be asked to come into hospital after fasting the night before. You will be shown to a room and given a gown to change into.   When you are ready you will be taken into the operating theatre and the anaesthetist will offer to insert an epidural catheter (fine plastic tube) into your back for pain relief after the operation. You will then have a general anaesthetic (to put you to sleep). Once you are anaesthetised, a bikini line cut will be made in your abdomen (tummy). This is wider than the size of the cut used for Caesarean section birth, and slightly higher up on the abdomen. If you are having open fetal surgery the uterus (womb) is then opened to allow access to the baby. If you are having fetoscopic surgery, the instruments are then inserted via small holes into the uterus.The baby’s spina bifida defect is repaired and the abdomen is closed. You will then be woken up.