An intrauterine device (IUD) is a small, T-shaped form of long-acting, reversible birth control placed inside the uterus to prevent pregnancy. A yeast infection, medically known as Vulvovaginal Candidiasis, is a common fungal infection caused by an overgrowth of the Candida species, most often Candida albicans, in the vagina. This infection causes uncomfortable symptoms like burning, itching, and thick discharge. Whether the IUD increases the chance of developing this fungal infection is a common concern, requiring an examination of current medical evidence.
The Evidence: IUDs and Fungal Infection Risk
The relationship between IUDs and yeast infections is not straightforward, and medical research presents mixed findings. Although the device is a foreign body that could theoretically alter the local environment, studies do not show a consistent or high increase in symptomatic infection rates for most users.
Research suggests a difference in risk between the two main types of IUDs. The non-hormonal, copper IUD may have a slightly higher association with Candida colonization compared to the hormonal IUD, particularly in the initial months after insertion. For example, one study noted that approximately 29.57% of copper IUD users had Candida detected three months post-insertion, compared to 22.95% of hormonal IUD users. This colonization does not always lead to a symptomatic infection.
One proposed mechanism is that the IUD’s string can act as a surface for Candida species to form a biofilm. This protective layer allows the fungus to cling to the device, potentially making the infection more persistent or recurrent. Biofilm formation is related to the presence of a foreign object, not the IUD type. However, the overall evidence does not support a significant, long-term increase in yeast infection risk compared to women using no contraception.
Why the Confusion? Differentiating Symptoms
The public association between IUDs and “infections” often stems from confusion between different types of vaginal health issues. Yeast infections are caused by a fungus and present with a thick, white, “cottage cheese-like” discharge, noticeable itching, and burning, but typically no strong odor. These symptoms are distinct from other common infections.
Bacterial Vaginosis (BV) is caused by an imbalance of bacteria and is characterized by a thin, gray or yellow discharge and a strong, often “fishy” odor. Pelvic Inflammatory Disease (PID) is a serious infection of the upper reproductive tract, presenting with more severe symptoms like pelvic pain, fever, and heavy, foul-smelling discharge.
IUD insertion carries a small, documented risk of BV or PID, mostly limited to the first three weeks following the procedure. Since these bacterial conditions cause discharge and discomfort, patients often mistakenly group them with yeast infections. This overlap in general discomfort, despite differing specific symptoms, is a source of public confusion linking the IUD to generalized infection risk.
Common Causes of Yeast Infections Independent of IUD Use
Most yeast infections that occur in IUD users are due to factors unrelated to the device itself. The primary cause of a yeast infection is a disruption in the natural balance of the vaginal microbiome, allowing the Candida fungus to overgrow.
Common triggers include:
- The use of broad-spectrum antibiotics, which eliminate protective bacteria, thus allowing the fungus to flourish.
- Uncontrolled diabetes or high blood sugar levels also provide a favorable environment, as the fungus thrives on sugar.
- Hormonal fluctuations, such as those experienced during pregnancy or due to certain high-estrogen birth control methods, can also increase susceptibility.
- Lifestyle factors like wearing tight, synthetic clothing or wet garments, which create a warm, moist environment that encourages fungal growth.
Practical Steps for Diagnosis and Treatment
If an IUD user suspects an infection, seeking medical confirmation is important to ensure proper treatment. Symptoms of a yeast infection can mimic those of BV or, less commonly, an early symptom of PID, and all of these conditions require different medications. A healthcare provider can perform a pelvic examination and analyze a sample of the discharge to accurately diagnose the cause, often through a microscopic or pH test.
For a confirmed yeast infection, standard antifungal treatments are available in both topical (creams or suppositories) and oral forms. These medications are safe to use with both hormonal and copper IUDs and do not affect the device’s placement or its effectiveness at preventing pregnancy. In cases of persistent or recurrent infections, especially when a biofilm is suspected, a medical provider may consider extended antifungal therapy to fully resolve the issue. IUD removal is generally reserved for rare instances where severe, recurrent, and treatment-resistant candidiasis is identified.