The most common endocrine disorder affecting pregnancy is diabetes mellitus, which is considered separately (see Chapter 102). Although there are several other conditions that may have obstetric implications, most have little specific obstetric anaesthetic relevance over and above considerations applicable to the non-pregnant state.
Special considerations and management options
Thyroid disease
Anaesthetic implications are as for non-pregnant patients. Goitre may increase in size in pregnancy. Fetal morbidity includes neonatal encephalopathy and goitre with maternal antithyroid treatment in rare cases. Acute hyperthyroidism (‘thyroid storm’) is an obstetric emergency that may cause premature labour, fetal loss or, rarely, fetal hyperthyroidism, or potentially life-threatening cardiac dysfunction.
Parathyroid disease
Primary hyperparathyroidism is associated with increased maternofetal morbidity with an increased incidence of pancreatitis, pre-eclampsia and fetal loss secondary to severe hyper- calcaemia. Medical management includes hydration and oral phosphates, and parathyroidectomy may be required.
Adrenal disease
Hypoadrenalism is a rare cause of collapse on the labour ward. Patients receiving steroid therapy may require extra dosage peripartum (see Chapter 150, Steroid therapy). Cushing’s syndrome is rare in pregnancy. Treatment strategies include surgical resection and medical therapy; in advanced pregnancy, treatment may be limited to the management of clinical manifestations such as hypertension.
Phaeochromocytoma is a rare but well-recognised cause of hypertension in pregnancy and may present as part of the multiple endocrine neoplasia syndrome. The condition may initially be misdiagnosed as pregnancy-related hypertensive disease, causing a delay in treatment and a peripartum maternal mortality of up to 50%. Unlike gestational hypertension or pre-eclampsia, hypertension associated with phaeochromocytoma is of paroxysmal nature and may develop before 20 weeks’ gestation. Medical management is classically with а-blockade first and then β-blockade, ensuring adequate fluid replacement. Magnesium therapy has also been used to control pre- and intraoperative hypertension. Regional anaesthesia has been safely used for labour and vaginal delivery. Combined caesarean section and excision of the tumour has been reported using both regional and general anaesthesia, with appropriate monitoring. More recently there have been reports of an elective two-step procedure, whereby patients are treated medically first, followed by caesarean section and then excision of the tumour.
Neuroendocrine disease
Most of the anaesthetic implications relate to the effects of any intracranial space-occupying lesion. Specific hormonal conditions are managed as for non-pregnant patients. Sheehan’s syndrome is pituitary infarction caused by severe hypotension (‘pituitary apoplexy’), originally described in association with placental abruption. Pregnant women are thought to be particularly susceptible to this phenomenon because the pituitary gland enlarges during pregnancy by about one-third and its blood supply is consequently more critical.
Other conditions
These are managed as for non-pregnant patients.
Key points
• Diabetes mellitus is the most common and important endocrine disease in pregnancy.
• General management of endocrine disease is as for non-pregnant patients.
• The clinical features of some endocrine disorders may overlap with pregnancy-related changes or conditions; a high index of suspicion is required for timely diagnosis.
Further reading
Biggar MA, Lennard TW. Systematic review of phaeochromocytoma in pregnancy. Br J Surg 2013; 100: 182-90.
Frise CJ, Williamson C. Endocrine disease in pregnancy. Clin Med (Lond) 2013; 13: 176-81.
Kennedy RL, Malabu UH, Jarrod G, et al. Thyroid function and pregnancy: before, during and beyond. J Obstet Gynaecol 2010; 30: 774-83.