Hormonal Contraceptive Use and the Risk of Provoked Vestibulodynia

Background:

Provoked vestibulodynia (PVD), previously called vulvar vestibulitis syndrome, is clinically defined as chronic, unexplained, vulvar pain or discomfort, confined to the vulvar vestibule, in response to contact or pressure. As a result, women with PVD experience pain on sexual intercourse, and many patients also have pain in response to non-sexual activities. The actual prevalence of PVD is unknown, but current evidence indicates that the lifetime cumulative incidence of vulvodynia approaches 15%. Currently, PVD is thought to be the leading cause of dyspareunia in premenopausal women. Once a woman with PVD develops the syndrome, symptoms may last for years; as a result, PVD has a profound effect on women's sexuality and psychological well-being.

The diagnosis of PVD is usually made by assessing for the presence of the modified Friedrich's criteria. These criteria consist of 1) a history of vulvar pain, dyspareunia or pain with tampon insertion, 2) tenderness of the vestibule when being touched with a cotton-tip applicator, and 3) no other identifiable cause for the pain (such as vaginitis, dermatitis etc.).

The etiology of this condition remains unknown. Proposed causes include chronic inflammation, peripheral neuropathy, genetic, immunologic and\or hormonal factors, infection, psychological disorders, sexual dysfunction, or disturbance in the central nervous system.

Several studies have demonstrated an increased risk of developing PVD secondary to hormonal contraceptive (HC) usage. The relative risk of developing PVD seems to rise with an increased duration of HCs use (at least up to 2-4 years of use), first use of HCs at a young age (<16 years), and the hormonal composition of HCs, specifically the progestogenic, estrogenic, and androgenic potency of the pills.

Several mechanisms of action have been suggested for HCs induced PVD:

- Alteration of vestibular hormonal receptors.

- Alterations of the morphological pattern of the vestibular mucosa(13).

- Decreased pain threshold.

- Alteration of serum free hormones levels.

Objectives/Purpose of the Study:

1. To assess the actual prevalence of HCs induced PVD in a prospective study.

2. To evaluate which of the components contained in the HCs (oral contraceptives, transdermal patch, vaginal ring) are associated with higher risk of HCs induced PVD, specifically; the dose of ethinyl estradiol (15, 20 and 30 mcg) and the progesterone component.

3. To evaluate which factors predispose the patient to HCs induced PVD. We will analyze both clinical (age, age at menarche, length of use, body mass index etc.), hormonal (E2, testosterone etc.) and altered gene expression factors.

The proposed study is a preliminary investigation aimed at estimating the rate of HCs induced PVD. The data from this study will enable the determination of the number of patients needed to obtain statistical significance in a future, larger study regarding patients' risk factors for developing PVD and HCs formulation.

For this pilot study the investigators will evaluate 200 patients and follow them for a total of 1 year after HC initiation. Since this is a novel study that has not been investigated, nor is there available statistics in the medical literature, the investigators anticipate that 200 patients will provide enough data regarding incidence of PVD development secondary to HCs use.

Definitions and measures to be used to diagnose HC induced PVD:

1. New onset of vulvar pain suggestive of PVD, i.e. symptoms of pain on vaginal penetration (insertional dyspareunia and/or pain with tampon insertion), following initiation of HCs.

2. On exam, tenderness localized within the vestibule when being touched with a cotton-tip applicator. The exam will be performed on defined points of the labia minora, labia majora and the vestibule in 5 defined points (1,5,6,7,11), with patients reporting pain verbally by a rating scale of 0 to 10 at each point.

3. No identifiable cause for the pain, such as vulvovaginal candidiasis, desquamative inflammatory vaginitis (DIV), herpes, dermatitis or vulvar dystrophy.

Time frame for completion: The investigators anticipate one year for patients' enrollment and another year for follow up. Data analysis and microarray analyses will be done during the third year. Data should be available within 3 years of study initiation.