IIH and Pregnancy

The decision to enter parenthood is exciting and life-changing. Carrying a baby is a unique journey you may wish to experience. The great news is, if you have IIH and want to become pregnant, you can, it will just require a bit more preparation.¹

Frequent visits to your neuro ophthalmologist and obstetrician before, during, and after pregnancy will be necessary to manage your IIH while protecting your developing baby. Communication with your medical team will help you be an advocate for you and your baby.

Throughout pregnancy some changes that occur to a woman’s body are obvious but some are not. Change also occurs in the brain such as a decrease in the size of the brain, an increase in the size of the ventricles, and an increase in the size of the pituitary gland.² These changes are a result of an increase in blood volume that is needed to support the growing baby. Some of these changes in the brain can aggravate IIH-type symptoms. A majority of women report IIH symptoms during the first and second trimester of pregnancy but they can appear at any time³. Having IIH does not exclude you from experiencing pregnancy.

IIH Management During Pregnancy

Managing IIH during pregnancy will include weighing the risk to the baby balanced by the benefit of symptom relief to the mother.

Imaging

Headache is the most common symptom experienced in IIH.⁴ Imaging tools such as a CT scan and magnetic resonance imaging (MRI) are the preferred studies used to detect changes in the brain. They are commonly ordered for new or worsening IIH symptoms. During pregnancy, if imaging is required, the risk versus benefit of radiation exposure to the developing baby will be considered. CT scan imaging of the brain is shown to be safe during pregnancy with the placement of a lead shield over the abdomen and pelvis. The use of MRI during pregnancy has not been well-studied to completely verify its safety to the baby.⁵ Contrast agents should be avoided while pregnant due to its unknown safety profile to the fetus.⁵

Medications and Pregnancy

The Food and Drug Administration (FDA) classifies medication use on pregnant and lactating mothers based on studies found on humans and animals and how it affects a developing baby (fetus). The categories are as follows:

Category A: Well-controlled human studies do not show a risk to the fetus

Category B: Animal studies do not show a risk but no study has been performed on humans

Category C: Animal studies have shown some negative effects, however no studies have been performed on humans

Category D: Studies on humans have shown negative effects on fetus but potential benefits to mother may outweigh risk to fetus

Category X: Studies on animals and humans have shown negative effects on fetus and benefits do not outweigh risks.⁶

Many pharmaceutical treatment options for migraine and headache relief are used for the treatment of IIH (tricyclic antidepressants, beta-blockers, and calcium channel blockers) but should be used with caution during pregnancy. All of these medications are classified as category C, showing harmful effects to the fetus in animal studies. Non-steroidal anti-inflammatory drugs (NSAIDs) are category B due to the increased risk of premature ductal closure of the fetus.⁷ This means that the baby cannot pump blood from the heart to the lungs causing heart and lung failure leading to death.

Acetazolamide is a carbonic anhydrase inhibitor (CAI) and is a common form of treatment for IIH. Acetazolamide (Diamox) works by decreasing the amount of cerebrospinal fluid made, allowing for a decrease in pressure of the brain. This medication is listed as a category C, showing negative effects to the fetus in animal studies. An alternative to acetazolamide are diuretics but most are also listed as a category C.

Weight loss

Aside from medications, there remain successful and safe options to treat IIH. The use of weight control during pregnancy was found to be the safest way to keep IIH symptoms at bay.⁸ Obesity is commonly associated with IIH, and if applicable, weight control should be discussed and undertaken. A reduction of 10% of total body weight (about 20 pounds in most people) prior to pregnancy can decrease the rate of complications during and after pregnancy⁹ and can avoid IIH-type symptoms.⁹

In one who is obese, achieving weight loss prior to pregnancy has proven to be the most effective intervention to improved overall health and longevity to both the mother and baby. According to the US Institute of Medicine (IOM), a woman with a body mass index (BMI) of 25 or greater should limit weight gain during pregnancy to 11-20 pounds.¹⁰ Other medical organizations recommend weight gain to be no greater than 8-13 pounds if one’s BMI is 30 or greater. This is to decrease the risk of complications associated with obesity and pregnancy (maternal diabetes, preeclampsia, preterm birth, and large for gestational age).⁸

Alternative Options

If IIH signs and symptoms are ongoing or worsening, the use of lumbar puncture can safely be performed while pregnant.⁷ Depending on the severity of symptoms, a lumbar puncture may need to be performed several times and may require admission to the hospital for close monitoring of symptoms. A lumboperitoneal shunt (LP shunt) or ventriculoperitoneal shunt are not preferred options during pregnancy as the end of the catheter placed in the abdominal cavity can disturb the growing uterus.⁸

Visual changes caused by papilledema can occur throughout pregnancy, but if left untreated, can progress to blindness. The most efficient way to detect papilledema will be with frequent visual field testing.⁷ If vision declines or papilledema is severe despite the use of medications or a lumbar puncture, then an optic nerve sheath fenestration (ONSF) will be required and the use of general anesthesia will be necessary.

Delivery

You can still be a candidate for a vaginal delivery if your IIH symptoms are controlled or absent.⁸ During active labor, when you push, the transient increase in blood pressure will cause an increase in intracranial pressure. A review of over 50 pregnant women with IIH noted that the seconds in which contractions and pushing occurs, there was no increased risk of any brain or vision injury.^8,9As every person is different, your obstetrician will decide what type of delivery (vaginal versus cesarean) will be safest for you and your baby.

Bottom line

Many women with IIH have uncomplicated pregnancies and deliver healthy babies. Being proactive with your health, informed about treatment risk and benefits, and communicating with your medical team will help in your journey of having a baby.

References

Sureda B, Alberca R. Pregnancy and benign intracranial hypertension. An Med Interna. January 8 1991;8:8–10.
Oatridge A, Holdcroft, A, Saeed N, et al. Change in Brain Size during and after Pregnancy: Study in Healthy Women and Women with Preeclampsia. American Journal of Neuroradiology. January 2002;23(1):19-26.
Huna-Baron R, Kupersmith M. Idiopathic intracranial hypertension in pregnancy. Journal of Neurology. February 18, 2002;249(8):1078–1081.
Ball A, Clarke C. Idiopathic intracranial hypertension. The Lancet Neurology. May 2006;5(5):433-442.
Tremblay E, Therasse E, Thomassin-Naggara I, et al. Quality Initiatives: Guidelines for Use of Medical Imaging during Pregnancy and Lactation. Radiographics. May 5, 2012;32(3):897-911.
Drugs.com. New FDA Pregnancy Categories. FDA Pregnancy Risk Information: An Update. Accessed August 2nd, 2022. https://www.drugs.com/pregnancy-categories.html
Kesler, A, Kupferminc M. Idiopathic Intracranial Hypertension and Pregnancy. Clinical Obstetrics and Gynecology. June 2013;56(2):389–396.
Thaller M, Wakerley B, Abbott S, et al. Managing idiopathic intracranial hypertension in pregnancy: practical advice. Pract Neurol. April 21, 2022;22:295-300.
Batra N, Prashant P, Wall M. Weight Management in Idiopathic Intracranial Hypertension. EyeRounds.org. Accessed June 2, 2022. https://webeye.ophth.uiowa.edu/eyeforum/tutorials/Weight-management-IIH.htm#:~:text=Establishing%20the%20role%20of%20weight,with%20this%20intervention%20%5B12%5D
Rasmussen K, Yaktine A. Institute of Medicine (US) and National Research Council Committee to Reexamining the Guidelines. Weight gain during pregnancy: reexamining the guidelines. Washington, DC: National Academies Press; 2009.

Edith Ruiz, PA-C

Edith Ruiz, PA-C is a certified physician assistant with over 14 years of clinical experience, including the care of neurological surgery and bariatric surgery patients. Additionally, she has several years of experience as a medical writer for healthcare companies to help connect patients to medical information.

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