Pregnancy and Chiari malformation: Review of the literature and current recommendations

By Diane Mueller, ND, RN, FNP-BC

A frequent topic of concern for young women with Chiari I malformation (CMI) with or without syringomyelia (SM) is the safety of pregnancy and delivery. Though the medical literature is replete with information about Chiari and syringomyelia, a search of the English literature revealed very few articles regarding pregnancy among women diagnosed with CMI &/or SM.

Anesthesia management of two patients with CMI and SM were reported by Parker, Broberg & Napolitano (1). The first was a 26 year old with SM diagnosed in childhood, presenting at 38 weeks gestation and the second a 30 year old diagnosed with CMI and SM presenting at 39 weeks gestation. Both were treated with epidural anesthesia without documented complications.

Landau, Giraud, Delrue and Kern (2) reported the case of a 31 year old woman diagnosed with CMI (cerebellar ectopia to C3) without SM, in addition to a seizure disorder. Symptoms included headache, vertigo and nausea. Neurologic exam revealed nystagmus and gait instability. Surgical “osteodural” decompression had been performed prior to pregnancy. The pregnancy was unremarkable, with the exception of persistent nystagmus, hperreflexia, and gestational thrombocytopenia.  Spinal anesthesia was chosen for cesarean (C-section) delivery of a healthy infant. The authors report no worsening of her neurologic symptoms.

In 2005, Mueller and Oró (3) presented a series of 7 patients with radiographic evidence of CMI. Three research questions were posed to determine if pregnancy, labor and delivery resulted in any change in the individual’s Chiari related symptoms. The average age of the patients was 29 years old (range 23-32 years). The mean tonsillar herniation among the participants was 9 mm (range 3-19mm). Two of the participants had syringomyelia. The most frequently reported symptom was headache. Three women delivered after diagnosis of CMI but prior to surgery, four delivered after decompression (1 cesarean, 3 vaginal). Three of the seven women had epidural anesthesia for vaginal delivery with no untoward symptoms reported.  No patients reported any significant increase in symptoms during or after delivery, and no complications of epidural anesthesia were reported.

Margarido, et al. (4) reported the case of a 30 year old woman with cervical post-traumatic syringomyelia (without CMI) in whom epidural anesthesia for elective C-section was chosen. The C-section using an epidural catheter was performed at 39 weeks gestation without complications.

A 31 year old woman with thoracic syringomyelia (without CMI) was presented in the 2011 case report by Nielsen, Bejjani and Vallejo (5). The patient required urgent C-section delivery due to worsening pain and intermittent lower extremity weakness/paralysis. General anesthesia was the method chosen for delivery, with no reported complications related to the syringomyelia.

The recent publication by Ghaly, Candido, Sauer and Knezevic (6) described a 34 year old woman who was diagnosed with CMI and extensive SM at age 19. The patient had undergone craniectomy, duraplasty, laminectomies and placement of syringopleural shunt prior to pregnancy. The follow-up imaging demonstrated worsening of cervical kyphosis and residual syrinx, therefore vaginal delivery was contraindicated. At 38 weeks gestation, a team approach was developed and the patient underwent fiberoptic intubation (allowing for neutral position of the neck) for general anesthesia and a successful C-section delivery. No change in neurologic status or symptoms was reported after the procedure.

The true risk of increased intracranial pressure in persons diagnosed with CMI &/or SM who undergo intrathecal or epidural anesthesia for delivery remains unclear. The use of epidural anesthesia involves risk of increasing pressure within the epidural and arachnoid space for patients with SM. Caution should be taken to avoid hyperextension of the neck in patients with CMI during endotrachial intubation for general anesthesia since it can further crowd the foramen magnum. Careful consideration should be taken to educate the woman and her family regarding the risks and benefits of each form of anesthesia. The successful management of pregnant women with the diagnosis of CMI &/or SM requires individual assessment of risk factors and a multidisciplinary approach that accounts for each woman’s individual neurologic status.


  1. Parker J.D., Broberg J.C., & Napolitano P.G. Maternal Arnold-Chiari type I malformation and syringomyelia: A labor management dilemma. Amer J of Perinatology, 19(8):445-449.
  2. Landau R., Giraud R., Delrue V., & Kern C. Spinal anesthesia for cesarean delivery in a woman with a surgically corrected type I Arnold-Chiari malformation. Anesth Analg. 2003 Jul;97(1):253-5.
  3. Mueller D.M., Oro’ J.J. Chiari I malformation with or without syringomyelia and pregnancy: case studies and review of the literature. Am J Perinatol, 2005 Feb;22(2):67-70.
  4. Margarido C., Pafeek M., Salman A., & Balki, M. Epidural anesthesia for Cesarean delivery in a patient with post-traumatic cervical syringomyelia. Can J Anesth. 2011 58:764-768.
  5. Nielsen J.L., Bejjani G.K., & Vallejo M.C. Cesarean delivery in a parturient with syringomyelia and worsening neurologic symptoms. Journal of Clinical Anesthesia. 201123:653-656.
  6. Ghaly R.F., Candido K.D., Sauer R., & Knezevic N.N. Anesthetic management during Cesarean section in a woman with residual Arnold-Chiari malformation type I, cervical kyphosis and syringomyelia. Surg Neurol Int. 2012 3:26.