Women on NuvaRing have developed Idiopathic Intracranial Hypertension (IIH). We are concerned because IIH can elevate pressure inside the skull, cause excruciating headaches, and permanent blindness.
What is NuvaRing?
NuvaRing is a contraceptive device developed by Merck & Co. that has been on the market since 2001. It is a flexible, O-shaped device that a woman inserts into her vagina. It slowly releases hormones that prevent pregnancy, including estrogen (ethinyl estradiol) and progestin (etonogestrel).
Does NuvaRing Cause Idiopathic Intracranial Hypertension?
No one knows if NuvaRing causes IIH. The condition is “idiopathic,” meaning that doctors do not fully understand what causes the disease. However, all cases of IIH involve abnormally high levels of cerebrospinal fluid, which puts pressure on the brain and optic nerve. Many risk-factors have been identified. IIH is most common in obese women of childbearing age. It is also more common among women who use birth control.
Studies Linking IIH and Birth Control
The New England Journal of Medicine published one of the first studies linking birth control and IIH in 1995. Researchers described 56 cases of IIH and optic edema in women on a subcutaneous birth control implant containing the hormone levonorgestrel. Other case reports have linked IIH with the use of exogenous estrogen and progestin-only birth control shots.
Complications of IIH
- Headaches: Clinical trials found that headaches (including migraines) occurred in 11.2% of women on NuvaRing. Headaches are also a symptom of IIH, but the conditions are not clearly related. Symptoms include dull pain that is often worst first thing in the morning. These symptoms can sometimes be relieved by draining cerebrospinal fluid.
- Blindness: About 5% of people with IIH develop blindness or vision loss. This complication occurs when the optic nerve is damaged. It may be associated with papilledema, a condition involving swelling of the optic disc. Most people with IIH report visual changes, such as double-vision, blurry vision, light-sensitivity, etc.
In May 2012, NuvaRing was associated with a 6.5-fold increased risk of blood clots compared to non-users in a study published by the British Medical Journal. NuvaRing was also associated with a doubled risk of blood clots compared to women who used birth control pills containing levonorgestrel.
Hormonal birth control increases the risk of arterial blood clots that travel to the brain and cause a stroke. Blood clots in the brain can also cause “secondary intracranial hypertension,” a syndrome that is similar to IIH. Both conditions occur when cerebrospinal fluid increases pressure inside the skull.