Combined Vaginal Ring (CVR)

Question 1

What are the 3 types of combined hormonal contraceptives (CHCs)?

Answer 1

Combined hormonal contraceptives (CHCs):

1. Oral contraceptives
2. Transdermal patch
3. Vaginal ring

Question 2

Briefly describe the mechanism of action of CVR

Answer 2

• CVR act primarily to inhibit ovulation.
  
  • Ovulation is inhibited by the oestrogen and progestogen components which act on the hypothalamo-pituitary axis to reduce production of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). With no surge in LH and FSH to stimulate the ovaries, ovulation does not occur.
• CVR also have contraceptive effects on cervical mucus and the endometrium.
  
  • The oestrogen component causes the endometrium to proliferate and grow.
  • The progestogen component prevents hyperplasia of the endometrium by opposing the proliferative effects of oestrogen.

Question 3

What are the indications of CVR?

Answer 3

• Contraception
• Hyperandrogenism (e.g. acne, hirsutism)
• Menstrual cycle disorders (e.g. menorrhagia, dysmenorrhea)
• Symptom control in endometriosis and leiomyomas

Question 4

What is the most common regime to take CVR? And why is this?

Answer 4

Insert one ring high into the vagina for 3 weeks of continuous use per cycle→ a new ring should be inserted after a 7-day ring-free break which then starts a new cycle.

Question 5

What are the health benefits of CVR?

Answer 5

• Reduced risk of ovarian, endometrial and colorectal cancer;
• Predictable bleeding patterns
• Reduced dysmenorrhoea and menorrhagia;
• Management of symptoms of polycystic ovary syndrome (PCOS), endometriosis and premenstrual syndrome;
• Improvement of acne;
• Reduced menopausal symptoms;
• Maintaining bone mineral density in peri-menopausal females under the age of 50 years.

Question 6

What are the side effects of CVR?

Answer 6

• Nausea and abdominal pain
• Headache
• Breast pain and/or tenderness
• Mood swings
• Menstrual irregularities

Question 7

What are the risks of CVR?

Answer 7

• Cardiovascular disease and stroke
  
  • Hypertension and myocardial infarction
• Venous thromboembolism
• Breast cancer
• Cervical cancer

Question 8

What are the contra-indications of CVR?

Answer 8

• BMI greater than 35
• Breast feeding
• Smoking over the age of 35
• Hypertension
• History of or family history of venous thromboembolisms
• Prolonged immobility due to surgery or disability
• Diabetes mellitus with complications e.g. retinopathy
• History of migraines with aura
• Breast cancer or primary liver tumours

Question 9

What is the guidance of vomiting or diarrhoea on CVR?

Answer 9

• Vomiting and diarrhoea and do not affect the bioavailability of the CVR
• No additional contraceptive measures (such as condoms) are needed if a woman vomits or has diarrhoea whilst using the CVR

Question 10

Briefly describe how to assess a woman for CVR

Answer 10

• Check the UK Medical Eligibility Criteria
• Enquire specifically about:
  
  • Migraine
  • Cardiovascular risk factors such as smoking, obesity, hypertension, previous venous thromboembolism, hyperlipidaemia and thrombophilia
  • Past and current medical conditions
  • Family history

Question 11

What is the efficacy of CVR?

Answer 11

• When the CVR is used perfectly→ 0.3% of women will conceive within the first year of use due to method failure
• When the CVR is used typically→ 9% will conceive within the first year of use due to method failure or user failure

Question 12

What are the advantages of CVR?

Answer 12

• The ring is more convenient to use, as it is inserted and left in place for 3 weeks and then removed for one week ring-free interval
• The CVR does not become less effective if the woman vomits or has diarrhoea
• The CVR appears to be at least as effective as COCP at preventing pregnancy

Question 13

What are the disadvantages of CVR?

Answer 13

• The most frequently reported undesirable adverse effects are headache, vaginal infections and vaginal discharge
• It may occasionally cause a foreign body sensation in the vagina or discomfort during intercourse
• It may become broken during use or may be expelled, compromising efficacy
• It may very rarely be inserted inadvertently in the urethra and possibly end up in the bladder
• There may be a delay in return to normal fertility after stopping treatment