Hormonal Contraceptives
Combined hormonal contraceptives include various forms such as oral pills, rings, and patches. The only ring available in the UK is NuvaRing, and the only patch is the Evra patch, which is not effective for those over 90 kg. All three methods have similar efficiency rates, with a 0.3% failure rate when used correctly.
Mechanism of Action
Combined hormonal contraceptives inhibit ovulation by affecting estrogen and progesterone levels on the hypothalamic-pituitary axis, leading to decreased FSH and LH production. This results in reduced estrogen and progesterone production, impacting cervical mucosa and endometrium.
Regimens for Combined Hormonal Contraceptives
- Standardized:
- Pills: 21 days with a 7-day free interval
- Patch: Applied for 1 week, three times in a month, with a 7-day free interval o Ring: Attached for 3 weeks, followed by a 7-day free interval
- Non-standardized:
- Shortened hormone-free interval (4-7 days)
- Extended regime: Decreased frequency of hormone-free intervals (e.g., tricycling approach)
- Continuous regime: Continuous use without a hormone-free interval
Starting the Pill
Initial assessments are necessary when starting the pill. For amenorrhoeic patients, contraception can be started at any time, ensuring they are not pregnant. Additional contraception is needed for the first 7 days (9 days for Qlaira).
Postpartum Considerations
- Non-breastfeeding patients:
- Do not start if less than 3 weeks postpartum, regardless of VTE risk factors. o Can start after 3 weeks if no VTE risk factors.
- Additional contraceptive methods may be needed.
- Breastfeeding patients:
- Can use CHCs from 6 weeks to 6 months onwards. o Do not use before 6 weeks postpartum.
After Miscarriage or Termination
Contraception can usually be started within 5 days. For Qlaira or Zoely, start on day 1. If started after 5 days, additional contraception is needed for 7 days (9 days for Qlaira).
Choice of Contraception
- Standard choice: Monophasic COCPs (30 mg ethinylestradiol with norethisterone or levonorgestrel).
- 12-month supply, reviewed at 3 months and then annually.
When to Start
- Day 1 of the cycle preferably, no additional contraception needed.
- Between days 2-5, no additional contraception is needed (except Qlaira or Zoely, which need 9 and 7 days, respectively).
- After day 5, additional contraception is needed for 7 days (9 days for Qlaira).
- If pregnancy cannot be excluded, start contraception and do a pregnancy test within 21 days.
After Oral Emergency Contraception
- UPA: Start up to 5 days later with 7 days of additional barrier protection.
- Levonorgestrel: Start immediately with 7 days of additional barrier protection.
Switching Between Contraceptives
- Between combined hormonal contraceptives: Switch directly, no additional protection is needed.
- From progestogen-only pills (except desogestrel): Switch at any time with additional barrier protection.
- From desogestrel POP or injectable progestogen: Start at any time; no additional contraception is needed.
- From implants: Depends on duration of use.
Adverse Effects and Advice
- Vomiting and diarrhoea: Specific approaches for different pills.
- Pros: Decreased risk of ovarian, endometrial, and colorectal cancer; improves acne; fertility returns when stopped.
- Cons: Does not protect against STIs; side effects include nausea, vomiting, breast pain, irregular bleeding; increased risk of cardiovascular disease, VTE, breast cancer, and cervical cancer.
Unscheduled bleeds
Rule out pregnancy, STIs, and gynaecological issues (e.g., cervical cancer, endometrial cancer). If normal, consider continuing COCP, changing dosage, or switching to a different form of contraception.
Surgery Considerations
Stop 4 weeks before major surgeries and restart 2 weeks after full mobilisation. Usually stopped by age 50, switching to non-hormonal methods or other contraceptives.
Missed Pill Advice
For missed pills (not for Qlaira and Zoely):
- If the hormone-free interval is prolonged beyond 7 days and unprotected intercourse occurs, consider emergency contraception + 7 days additional contraception, do a pregnancy test & take the missed pill ASAP and continue the pill as normal after.
- If missed 1 pill in weeks 1-3 – take the missed pill, there is no need for EC if the patient has taken the pill correctly in that week & 7 days prior (also no additional barriers needed)
- If more than 2 pills (>72 hours) are missed in week 1 with unprotected intercourse, use emergency contraception, take the missed pill, continue taking the pill, do a pregnancy test and use additional barrier protection
If more than 2 pills are missed in weeks 2 or 3, no need for emergency contraception if used correctly in the past 7 days. If missed in the last week before the hormone-free interval, omit the hormone-free interval.