The pregnant woman may have suffered (and/or recovered) from a neurological condition before she became pregnant, or she may develop neurological disease while pregnant (Table 118.1).
Problems and special considerations
Traditionally, regional analgesia and anaesthesia have been avoided in most chronic neurological diseases because of the fear of making the woman’s condition worse or being blamed should a worsening occur. Since randomised controlled trials are lacking for most of these conditions, traditional prejudices persist, although such evidence that there is supports regional techniques in many cases.
Table 118.1 Neurologicalconditions that may be seen in pregnancy
|
Pre-existing |
||
|
Previous history |
Trauma Infection Tumour |
Head injury Spinal cord injury Meningitis Acute post-infective neuropathy |
|
Established neurological disease |
Cerebrovascular disease Migraine Myasthenia gravis Spina bifida Epilepsy Multiple sclerosis Idiopathic intracranial hypertension |
|
|
Arising during pregnancy |
||
|
Trauma Infection Tumour |
Acute head injury Acute spinal cord injury Meningitis Acute post-infective neuropathy |
|
Acute neurological conditions may put both the mother and the fetus at risk. Anaesthetic input may be required for peripartum analgesia or anaesthesia, acute medical management of critically ill patients, or surgery indicated by the neurological condition.
Management options
The management of both groups of women depends on the nature of the disease, its effects on pregnancy and delivery and the implications of the physiological changes of pregnancy.
Ideally, women who have a diagnosed neurological disease should be counselled before conception, so that they are aware of the possible problems that may be associated with their disease during pregnancy and delivery. In practice, the majority of women are seen after conception, and the aim should be early antenatal assessment. The effect of maintenance therapy and the necessity to change treatment to avoid teratogenic effects must also be considered. Good communication between the clinicians involved is essential in the management of these women. Clear guidelines for care should be written in the medical record and should be revised and updated as necessary.
Neuroimaging may occasionally be required during pregnancy. Magnetic resonance imaging is generally perceived to be a safe modality in pregnant women; the risks of harm to the fetus secondary to tissue heating or exposure to high levels of noise are considered largely theoretical. Some authors, however, advise caution with its use in the first trimester. Ionising radiation is associated with the potential risks of pregnancy loss, fetal malformations or an increased incidence of childhood malignancy, and the risk is related to the stage of gestation and the total dose of radiation delivered. If computerised tomography is deemed essential in pregnancy, measures to minimise fetal radiation exposure should be taken. Gadolinium or iodinated contrast media may be associated with adverse fetal effects and should be reserved for situations where there is a strong clinical indication for their use.
Key points
• Neurological conditions may already be present before pregnancy or may arise acutely during pregnancy.
• Management depends on the condition, the effects on pregnancy and the effects of pregnancy on the condition.
• Early assessment and drawing up of management plans should take place whenever possible.
Further reading
American College of Obstetricians and Gynecologists’ Committee on Obstetric Practice. Opinion no. 656. Guidelines for diagnostic imaging during pregnancy and lactation. Obstet Gynecol 2016; 127: e75-80.
Hopkins AN, Alshaeri T, Akst SA, Berger JS. Neurologic disease with pregnancy and considerations for the obstetric anesthesiologist. Semin Perinatol 2014: 38: 359-69.
Ng J, Kitchen N. Neurosurgery and pregnancy. J Neurol Neurosurg Psychiatry 2008; 79: 745-52.