Contraception – Combined Hormonal Contraception

Combined Hormonal Contraception includes:

  • Combined Oral Contraceptive pill (COC)
    • majority are fixed dose – containing 20-35µg of ethinylesteradiol (EE) with a progesterone
    • 21 days of active pill with 7 days of no pills or dummy pills
    • The first 7 pills inhibit ovulation and the next 14 maintain anovulation
    • They usually have a withdrawal bleed during the dummy pills
    • Other one contains Estradiol Valerate (Qlaira)
  • Combined Transdermal Patch (CTP)
    • patch that contains EE and norelgestromin
    • one patch for the first week to surpress ovulation then patch is replaced weekly for two weeks, then a patch free week
  • Combined Vaginal Ring (CVR)
    • releases EE and etonogestrel
    • Put into vagina for 21 days then a 7 day ring free period


How does it work?

  • The bleed during the hormone free interval is a withdrawal bleed from lack of hormones rather than a menstrual bleed
  • Continuous CHC regimes are used but this is off licence and patients should be aware of that

Initial Assessment

  • Detailed history and recheck the history annually
    • migraine
    • drug use
    • family medical history
    • smoking
  • Blood pressure
  • BMI

If on enzyme inducing drug

  • Enzyme inducing drugs reduce efficiency
  • She could switch to another method they may wish to carry on but use additional methods
  • they need to carry on these additional methods for 28days after stopping enzyme inducer
  • If they don’t want to use other methods they could increase the COC dose to at least 50µg EE (max 70µg EE) and use and extended (to have 4 pill free days)  or tricycling regime (just 3 pill free periods)



  • If on lamotrigine (except when in combination with sodium valporate) they probably shouldn’t be on CHC (well “the risks may outweigh the benefits”)
  • There’s a risk of reduced seizure control on the CHC
  • And theres a risk of toxicity during the pill free period

Emergency Contraception

  • UPA-EC has the risk of reducing the efficiency of the CHC
  • Advise additional precautions for
    • 14 days after taking UPA
    • 9 days if starting the POP
    • 16 days if taking the Qlaira (off licensce)


Risks / Contraindictions

  • Thromboembolism (VTE) risk is approximately doubled – but absolute risk is still very low
  • Personal history of VTE is contraindication – don’t take a negative thrombophillia screen as an ok to prescribe as there’s some mutations that are missed
  • Don’t do a thrombophillia screen prior to prescribing
  • Smoking if over 35years is a contraindiction
  • There is a very small increased risk of ischaemic CVA
  • If BP is elevated it’s a no-go
    • Systolic BP above 160 or
    • Diastolic BP above 95
  • BMI above ≥35  – risks outweigh benefits
  • Migraine with aura is a contraindication


  • Small increase risk of breast cancer but this comes back to normal after stopping
  • Small increased risk of cervical cancer – related to duration of use
    • Make sure they are up to date with cervical screening
  • Remeber “Bad for Becca and Catie, Good for Ollie and Evie and Poocy”) 
GOod For Ovary and Endometrium & poo track (colorectal)
  • REDUCED risk of endometrial and ovarian 
  • This protection continues several years after stopping
  • Also reduces risk of colorectal cancer
  • CHC doesn’t effect overall mortality

Also Good

  • May improve acne 
  • May reduce menstrual pain and bleeding
  • May reduce menopausal symptoms


Mood changes / weight

  • Some evidence of it affecting mood but nothing to show it causes depression
  • Current evidence doesn’t support the idea that it makes users put on weight


  • Tell them to take precautions to stay active if on flights longer than three  hours
  • If trekking over 4500m more than a week they should probably switch to an alternative