Birth control pills, such as Yaz, have been linked to Benign Intracranial Hypertension (BIH). This severe disease causes elevated pressure inside the skull, which can damage optic nerves and cause blindness.
What is Yaz?
Yaz is a birth control pill manufactured by Bayer HealthCare. Yaz contains estrogen (ethinyl estradiol) and progestin (drospirenone), which prevent pregnancy by thickening cervical mucous and inhibiting ovulation.
What is the problem?
Benign Intracranial Hypertension (BIH) occurs when high levels of cerebrospinal fluid increase pressure inside the skull, causing excruciating headaches. Untreated, BIH can also cause blindness. Because BIH is not actually “benign” (harmless), it is now known as Idiopathic Intracranial Hypertension (IIH)>.
Experts do not know what causes BIH. However, Yaz and other birth control pills are possible risk-factors that could increase the chances of this disease. Norplanon, a birth control implant containing levonorgestrel, was associated with 56 cases of BIH in a study published in 1995. Birth control injections (progestin-only) and estrogen have also been linked to cases of BIH.
Secondary Intracranial Hypertension and Blood Clots
Soon after Yaz was approved in 2006, it quickly become one of the most popular birth control pills of all time. The success rapidly faded after researchers found that drospirenone, the progestin in Yaz, was associated with up to a three-fold increased risk of blood clots compared to other progestins.
The problem with blood clots is that they can potentially travel to the brain and cause a stroke. In rare cases, blood clots in the brain can cause secondary intracranial hypertension. Similar to BIH, this condition causes high pressure inside the skull due to elevated levels of cerebrospinal fluid. Both conditions cause the same physical symptoms and can become chronic.
- Headache: Nearly 7% of women on Yaz reported headaches or migraines during clinical trials. Headaches are also the most common symptom of BIH. Without treatment, headaches can cause excruciating pain and become more and more frequent.
- Blindness: Permanent loss of vision most serious complication of BIH and the most common reason for needing surgery to drain cerebrospinal fluid from the skull. Some people develop papilledema (swelling of the optic disc). Symptoms may include double-vision, blurry vision, enlargement of the blind spot, and more.