The 2020 guide to CHC: no break please, we’re British

“Did you know you can now take the pill continuously?”

“Yeah, I’ve been doing that for years”

*get notebook out* “Can you tell me more about that?”

After being terrified of prescribing back-to-back COCP for more than 3 months and making uteruses (uteri?) thicken up and eventually explode, I can relax. Tailored COCP regimens (i.e. woman-focused rather than ‘medical desire to mimic periods’-focused) are officially A Thing.

All women who are medically eligible to use CHCs can be given the choice of a tailored regimen

Nash Zachary, Thwaites Annette, Davies Melanie. Tailored regimens for combined hormonal contraceptives BMJ  2020;  368 :m200  doi: https://doi.org/10.1136/bmj.m200 

How do we explain this?

Key concepts:

  • If you take a break, it should be no more than 7 days.
  • When restarting after a break, you need to take it for at least 21 days back to back before you can take another break.*
  • Everything after that is up to you

Another key concept:

The hormone-free interval can be evil. You’ll probably bleed during it, and a lot of side effects like breast tenderness, headaches, migraines etc. happen in and around this time.

These are the key concepts that allow the woman to choose her own regime.

All of the following options flow from this:

  • Continous use, literally every day (less total bleeding days, but there will almost definitely be irregular unscheduled bleeding, especially early on)
  • Continous use, but stop for 4 days when unscheduled bleeding (usually spotting), then restart (total number of withdrawal bleeds still less than with 21/7 use, but less predictable).
  • About to go on holiday? As long as you’ve been taking the pill for at least 21 days back to back, why not get in the holiday mood with a hormonal free interval for 4 days just before you travel, so you are much less likely to bleed whilst on holiday?
  • 63/4, 63/7, 84/4 etc (good balance of predictability and minimising hormone-free interval side effects, but you may still get some unscheduled bleeding)
  • 21/4 (shortened hormonal free interval and lower risk of unintended pregnancy if a pill or two missed early after the break. In fact, why isn’t this is default “traditional” regimen?)

Patient FAQs

Don’t I need a period?

You weren’t having periods even with your 21/7 regimen, just withdrawal bleeds from a hormone-free interval. There is no reason why women need to experience the joys of bleeding during a hormonal free interval.

Doctor FAQs

Won’t the endometrium thicken?

The endometrium doesn’t become a proliferative monster with continuous COCP use.

Johnson JV, Grubb GS, Constantine GD. Endometrial histology following 1 year of a continuous daily regimen of levonorgestrel 90 micro g/ethinyl estradiol 20 micro g. Contraception 2007;75:23–6. https://www.ncbi.nlm.nih.gov/pubmed/17161119

What pill do I use?

It must be monophasic. FSRH guidelines suggest first line choice of CHC for any regimen contains ≤30 μg ethinyloestradiol with progestogen of either levonorgestrel or norethisterone, as they have been associated with the lowest rates of venous thrombosis.

This is an off-licence use, but it’s supported by the FRSH and BMJ.