Progestogen only implant

• Overview:

  • Small (4cm) flexible plastic rod that is placed in the upper arm, beneath the skin and above subcutaneous fat
  • Slowly releases progestogen into the systemic circulation
  • Lasts for 3 years
  • More than 99% effective
  • Nexplanon s the implant used in the UK - contains 68mg of etonogestrel - licensed for 18-40 year olds
• The progestogen-only implant has very few contraindications and risks. The only UKMEC 4 criteria for the implant is active breast cancer.
• The progestogen-only implant works by:

  • Inhibiting ovulation
  • Thickening cervical mucus
  • Altering the endometrium and making it less accepting of implantation
• Inserting the implant on day 1 to 5 of the menstrual cycle provides immediate protection. Insertion after day 5 of the menstrual cycle requires seven days of extra contraception (e.g. condoms), similar to the injection.
• Insertion:

  • One third the way up the upper arm on the medial side
  • Lidocaine
  • Specially designed device is used to insert the implant horizontally, beneath the skin and above the subcutaneous fat
  • Should be palpable immediately after insertion
  • Pressing on one end of the implant should make the other end pop upwards against the skin
• Removal:

  • Lidocaine
  • Small incision made at one end of the device
  • Device removed using pressure on the other end or forceps
  • Contraception is required immediately after it has been removed
• Benefits:

  • Effective and reliable contraception
  • It can improve dysmenorrhoea (painful menstruation)
  • It can make periods lighter or stop all together
  • No need to remember to take pills (just remember to change the device every three years)
  • It does not cause weight gain (unlike the depo injection)
  • No effect on bone mineral density (unlike the depo injection)
  • No increase in thrombosis risk (unlike the COCP)
  • No restrictions for use in obese patients (unlike the COCP)
• Drawbacks:

  • It requires a minor operation with a local anaesthetic to insert and remove the device
  • It can lead to worsening of acne
  • There is no protection against sexually transmitted infections
  • It can cause problematic bleeding
  • Implants can be bent or fractured
  • Implants can become impalpable or deeply implanted, leading to investigations and additional management
• Rarely the implant can become impalpable or deeply implanted. Women are advised to palpate the implant occasionally, and if it becomes impalpable, extra contraception is required until it is located.
• The FSRH guideline on the implant (2014) state approximately:

  • 1/3 have infrequent bleeding
  • 1/4 have frequent or prolonged bleeding
  • 1/5 have no bleeding
  • The remainder have normal regular bleeds