zzzzzPRE-NATAL SURGERY FOR SPINA BIFIDA:
GOOD OR BAD?
I was born with spina bifida myself, and am now a full-time
wheelchair user, so it was to be expected that I would be extremely
interested in reports of babies with spina bifida having surgery pre-natally,
which promised to considerably reduce their disabilities.
However, as is often the way with "medical breakthroughs"
it turns out that the whole issue is far more complex than it appears.
The Lancet ('Is the case for fetal surgery for spina bifida proven?'
20/11/99) reported that two groups had independently reported having
performed pre-natal surgery on babies with spina bifida, led by Dr.
Joseph Bruner at Vanderbilt University Medical Center in Nashville TN
USA and Dr. Scott Adzick at the Children's Hospital in Philadelophia PA,
USA. Of the Nashville babies the average age at delivery was 33.2 weeks
and five were born before 30 weeks. Four of the ten Philadelphia babies
were delivered prematurely and one of these died.
A high proportion of babies with severe spina bifida also have
hydrocephalus, a build up a cerebro-spinal fluid within the ventricles
of the brain, and many require the insertion of a shunt shortly after
birth to drain away the fluid and prevent the head swelling, which can
cause brain damage. Some babies with spina bifida and hydrocephalus also
have Arnold-Chiari malformation, a kind of hindbrain herniation. The
Nashville team found that the need for shunt placement for hydrocephalus
was significantly lower among babies operated on pre-natally, and also
that there was a decrease in the number who had hindbrain herniation.
Neither of the teams has yet assessed whether there is any
improvement in the most obvious features of spina bifida - paralysis of
the legs causing walking difficulties, bladder and bowel function and
cognitive ability. However, Dr.Bruner has stated that so far there has
been no significant change in leg function in the operated babies. He
suggests that operating earlier (21 or 22 weeks) could result in
improved leg function but the risks would then increase - if labour
started then, few if any babies would survive.
To the risks of the surgery (which the baby would need anyway soon
after birth) has to be added the substantial risks associated with
premature birth - death and possibly even additional disability.
There is also the question of risk to the mother to consider. In a
study of 29 babies operated on by Dr. Bruner, 48% of the mothers
developed olighydramnios (a low volume of amniotic fluid) compared with
only 4% in the control group, and 50% had preterm uterine contractions,
compared with 9% of controls. There were also other reports of maternal
complications including uterine rupture and obstruction of the bowel. It
is notable that neither of the teams has yet investigated the long term
effects of pre-natal surgery on the mother's future ability to conceive
and carry another child.
Dr. Carys Bannister, paediatric nuerosurgeon at St. Mary's Hospital
Manchester warned that in these operations "modest short-term
benefits were achieved only at the cost of great risk to both fetus and
mother." She also mentioned that she was concerned that there was a
lack of "pictorially convincing evidence of reduction in hindbrain
herniation" from MRI scans.
It may be tempting to suppose that the availability of such surgery
will reduce the numbers of babies with spina bifida being aborted
(currently about 85% of those with the most severe form are aborted),
and will also focus the minds of both doctors and parents on the
humanity and unique preciousness of the babies involved. Sadly this
seems not to be the case, at least for Dr. Bruner, who admits he
continues to abort babies with spina bifida, if that is the parents'
"choice." It would seem that he has the same blinkered view as
many other doctors - that the fetus has value only if s/he is valued by
the mother. Mothers who willingly put their own lives and health at risk
for the good of their unborn child would surely not have aborted anyway.
Indeed Dr. Bruner says that "When our parents come to us, we ask
everyone what's the worst that could happen? Interestingly enough, they
all say the same thing: that the worst that could happen is that my baby
could die." Dr. Carys Bannister has said that the children already
operated on should be followed up for at least 5 years before deciding
whether or not to continue with pre-natal surgery.
Obviously, no one would be more pleased than me if babies with spina
bifida could have their disabilities reduced, but I do feel that the
case is far from proven. Indeed, given the very real risks to both
mother and baby, and the limited success so far achieved, I would be
reluctant to recommend such surgery to parents. Each individual human
life has infinite value, and it is better to be alive and disabled than
to die early in an attempt to reduce disability!
Alison Davis February 2000