Cerebrospinal fluid shunts in the maternity context

As a result of advances in medicine, midwives and obstetricians are increasingly seeing a number women with complex medical histories. This may include women who have been born with hydro cephalus, or who have idiopathic intracranial hyper tension. This article will examine the issues faced by women with shunts draining cerebrospinal fluid into the peritoneal cavity during their pregnancy.

Cerebrospinal fluid (CSF) is continually produced by the chloride plexus located within the lateral and fourth ventricles of the brain (Figure 1). In adults, around 500 ml is produced per day, with a circulating volume of approximately 150 ml (Sakka et al, 2011). Hydrocephalus is a complex condition resulting in an increase in CSF. It can be caused by a primary or secondary condition. This increase in fluid causes a rise in intracranial pressure (ICP) (Figure 2), which can lead to neurological deterioration. Symptoms include reduced conscious level, headaches, nausea, papilledema (swelling of the optic disc) which can cause visual deterioration, and issues with gait (Samandouras, 2010). Treatment options vary depending on the cause. In cases where hydrocephalus is the result of another underlying condition, such as a brain tumour, an operation to treat the primary cause, such as reduction or removal of the tumour, may be sufficient to improve the flow of CSF and therefore treat the hydrocephalus. In most cases, however, a CSF shunt is required; this will drain the excess fluid to another location, from which it is reabsorbed.