How to Use This Article
Disclaimer: this is a concise educational article on non-emergency contraception:
- It lists only the most common or clinically significant UKMEC category 3 and 4 conditions for each contraceptive method.
- Conditions that are UKMEC category 1 or 2 (generally safe to use) are not shown.
- It lists only the most common or clinically significant adverse effects for each contraceptive method.
This article organises everything important on non-emergency contraceptives into 2 main categories:
- By contraceptive method – information is grouped under each type of contraceptive method.
- By common clinical scenarios – information on various contraceptive methods is grouped under each clinical theme.
Note that there are significant overlaps between these 2 categories, but both should be read and studied to cover most of contraception.
Background Information
Contraceptive Efficacy
The following data is extracted from the FSRH UKMEC and arranged in ascending order of failure rate (from most effective to least effective), by perfect use rate.
| Method | Typical Use Failure Rate | Perfect Use Failure Rate |
|---|---|---|
| Implant | 0.05% | 0.05% |
| Levonorgestrel intrauterine system | 0.2% | 0.2% |
| Copper intrauterine device | 0.6% | 0.6% |
| DMPA injection | 6% | 0.2% |
| COCP | 9% | 0.3% |
| POP | 9% | 0.3% |
| Patch / Ring | 9% | 0.3% |
| Fertility awareness methods | 24% | 0.4%–5% |
| Male condom | 18% | 2% |
| Female condom | 21% | 5% |
| Diaphragm | 12% | 6% |
| Withdrawal | 22% | 4% |
UK Medical Eligibility Criteria (UKMEC)
UKMEC is a system used to classify the safety of contraceptive methods:
| UKMEC | Interpretation |
|---|---|
| 1 | No restriction |
| 2 | Advantages generally outweigh risks |
| 3 | Risks usually outweigh advantages (avoid) |
| 4 | Unacceptable health risk (absolute contraindication) |
Contraception by Method
Combined Hormonal Contraception (CHC)
This section covers:
- Combined oral contraceptive pill (COCP)
- Transdermal patch
- Vaginal ring
Mechanism of Action
Primary action: inhibition of ovulation (by suppressing mid-cycle LH surge)
Secondary action:
- Thickening of cervical mucus (from the progesterone component)
- Endometrial thinning
Route and Schedule
Combined Oral Contraceptive Pill (COCP)
There are 3 main regimens:
| Regimen | Description |
|---|---|
| Standard cyclic regimen | 2 cyclic regimens:
The patient would experience withdrawal bleeding during the hormone-free interval. |
| Extended regimen | Each cycle is made up of 63 days (3 packs) of active pill, followed by a 4-7 day hormone-free break
The patient would experience withdrawal bleeding during the hormone-free interval. |
| Continuous regimen | No scheduled hormone-free break
Withdrawal bleeding is not expected, although some users may experience light breakthrough bleeding or spotting over time. |
The extended and continuous COCP regimens offer no extra contraceptive benefits, but have extra therapeutic benefits in dysmenorrhoea and heavy menstrual bleeding.
CHC Transdermal Patch
Standard cyclic regimen: one patch changed every week for 3 weeks, followed by 1 patch-free week.
Just like COCP, extended and continuous use is possible.
CHC Vaginal Ring
Standard cyclic regimen: inserted for 3 weeks, then removed for 1 week.
Just like COCP, extended and continuous use is possible.
Time Until Reliable Contraception
- If started on day 1-5 of the menstrual cycle → immediately effective (no additional protection needed)
- If started on any other days → use additional contraception (e.g. condoms) for 7 days (only effective after taking 7 consecutive pills)
Adverse Effect
Less serious adverse effects:
- Breakthrough bleeding – common in the first month of use
- Mood changes
- Weight gain
- Nausea
- Breast tenderness
Serious adverse effects:
- Venous thromboembolism
- Arterial events (stroke, myocardial infarction)
- Hypertension
- Breast cancer
- Cervical cancer (small increase)
Importantly, CHC reduces the risk of endometrial and ovarian cancer.
COCP is shown to improve:
- Heavy menstrual bleeding
- Irregular bleeding
- Dysmenorrhoea
Caution and Contraindications
UKMEC 4 (unacceptable health risk of CHC is used), grouped according to its rationale:
| Rationale | Conditions |
|---|---|
| Hormone-sensitive tumour risk |
|
| Thrombosis risk |
|
| Cardiovascular disease risk |
|
| Oestrogen impact on infant | Breastfeeding <6 weeks postpartum |
| Liver function risk | Severe cirrhosis |
Selected important UKMEC 3 (risk usually outweighs benefits, specialist input needed):
- Past breast cancer
- ≥35 y/o + migraine without aura
- Smoking ≥35 y/o + smoke <15 cigarettes / day
- Hypertension
- BMI ≥35 kg/m2
- 1st-degree relative with VTEVenous thromboembolism event at <45 y/o
- Diabetes with vascular complications
- Gallbladder disease
- Cholestasis (past COC-related)
- Use of liver enzyme-inducing drugs
Management of Incorrect Use
Note this section applies only to CHC being used in the standard cyclic regimen:
- COCP: 21/7 regimen without placebo pills
- Combined vaginal ring: 21 days of ring in place, followed by 7 day ring-free interval
- Combined transdermal patch: patch replaced weekly for 3 weeks, followed by 7 day patch-free interval
The management depends on how many doses are missed and at what time of the cycle the dose is missed.
The following information assumes that prior to the missed dose, there was correct use in the previous 7 consecutive days.
Incorrect Use of COCP
The management depends on how many pills are missed and at what time of the cycle the dose is missed.
1 Missed Pill (>48 hours since last pill was taken)
ALL patients (regardless of what week the pill is missed):
- Take the missed pill as soon as possible (2 pills would be taken on the same day: 1 missed pill + 1 scheduled pill)
- Continue the remaining pills at the usual time
- No additional contraception needed
- Emergency contraception is NOT required
2 or More Missed Pill (>72 hours since last pill was taken)
ALL patients:
- Take the most recent missed pill as soon as possible (2 pills would be taken on the same day: 1 missed pill + 1 scheduled pill. But do not take both missed pills)
- Continue the remaining pills at the usual time
- Use condoms / avoid sex until pills have been taken for 7 consecutive days
Additional action, depending on which week the pills are missed:
- Week 1 → consider emergency contraception if UPSI has taken place during the hormone-free interval or week 1
- Week 2 → nothing else (emergency contraception not required)
- Week 3 → omit hormone-free interval and start new pack immediately at week 4
If oral emergency contraception is necessary, levonorgestrel is generally preferred over ulipristal acetate
- As levonorgestrel allows immediate restart of COCP
- While ulipristal acetate interacts with hormonal contraception, you must delay restarting COCP for 5 days
If >7 consecutive pills are missed at any time:
- Manage as a new start contraception
- Consider emergency contraception and pregnancy test
- Use condoms or avoid sex until pills have been taken for 7 consecutive days
- Start new COCP packet
Late Restarting After Hormone-Free Interval
Defined by ≥9 days since last active pill was taken:
- Take the most recent missed pill as soon as possible
- Continue the remaining pills at the usual time
- Use condoms / avoid sex until pills have been taken for 7 consecutive days
- Consider emergency contraception if UPSI has taken place during or after the hormone-free interval
For pills, the hormone-free interval is considered to start 24 hours after the last pill is taken. Therefore, the cut-off for additional action is 9 days.
If a woman took her last pill before a hormone-free interval at 9 am on Monday, so long as she restarts before 9 am on Wednesday of the following week (just less than 9 days later) she does not need to take additional action.
If she starts at or after 9 am on the Wednesday of the following week (9 days or more later), additional action is required.
Incorrect Use of Combined Vaginal Ring
The management is essentially identical to the incorrect use of COCP, the only difference is:
- Unscheduled ring removal for <48 hours corresponds to 1 missed COCP pill
- Unscheduled ring removal for ≥48 hours corresponds to 2 or more missed COCP pills
Unscheduled Ring Removal for <48 Hours
ALL patients (regardless of what week it is):
- Insert the ring as soon as possible
- Keep the ring in until scheduled ring removal day
- No additional contraception needed
- Emergency contraception is NOT required
Unscheduled Ring Removal for ≥48 Hours
ALL patients:
- Insert the ring as soon as possible
- Keep the ring in until scheduled ring removal day
- Use condoms / avoid sex until ring has been used for 7 consecutive days
Additional action, depending on which week the ring is removed:
- Week 1 → consider emergency contraception if UPSI has taken place during the hormone-free interval or week 1
- Week 2 → nothing else (emergency contraception not required)
- Week 3 → omit hormone-free interval and start new cycle immediately
Incorrect Use of Combined Transdermal Patch
The management is essentially identical to incorrect use of COCP, the only difference is:
- Unscheduled patch removed for <48 hours OR <48 hours of delayed schedule removal corresponds to 1 missed COCP pill
- Unscheduled patch removed for ≥48 hours OR ≥48 hours of delayed schedule removal corresponds to 2 or more missed COCP pills
Delayed schedule removal of the patch means that the same patch has been continuously used for additional hours.
Unscheduled Patch Removed for <48 hours OR <48 hours of Delayed Schedule Removal
ALL patients (regardless of what week it is):
- Attach a new patch as soon as possible
- Keep the new patch on until scheduled removal day
- No additional contraception needed
- Emergency contraception is NOT required
Unscheduled Patch Removed for <48 hours OR <48 hours of Delayed Schedule Removal
ALL patients:
- Attach a new patch as soon as possible
- Keep the new patch on until scheduled removal day
- Use condoms / avoid sex until ring has been used for 7 consecutive days
Additional action, depending on which week it is:
- Week 1 → consider emergency contraception if UPSI has taken place during the hormone-free interval or week 1
- Week 2 → nothing else (emergency contraception not required)
- Week 3 → omit hormone-free interval and start new cycle immediately
Progestogen-Only Pill (POP)
The FSRH UKMEC 2019 only included 3 POPs that are licensed in the UK at the time of publication:
- Norethisterone (1st generation)
- Levonorgestrel (2nd generation)
- Desogestrel (3rd generation)
Mechanism of Action
Primary action: thicken cervical mucus → impermeable to sperm
Route and Schedule
Oral, once daily with no pill-free interval (to be taken continuously every day).
- Traditional POP (levonorgestrel and norethisterone) must be taken within 3 hours of the usual time
- Desogestrel (3rd generation POP) must be taken within 12 hours of the usual time
Time Until Reliable Contraception
- If started on day 1-5 of the menstrual cycle → immediately effective (no additional protection needed)
- If started on any other days → use additional contraception (e.g. condoms) for 2 days (only effective after taking 2 consecutive pills)
Adverse Effect
- Menstrual changes
- Irregular bleeding – most common
- Spotting
- Amenorrhoea
- Breast tenderness
- Acne
- Headache
- Functional ovarian cysts
Unlike COCP, POP does NOT increase risk of venous thromboembolism and cardiovascular disease (e.g. stroke, myocardial infarction).
POP can also be used in migraine with aura (UKMEC 2) (but UKMEC 4 for COCP).
Caution and Contraindications
There are very few contraindications for POP, important ones:
- Current breast cancer (UKMEC 4)
- Past breast cancer (within the past 5 years)
- Severe decompensated liver cirrhosis
- Use of enzyme-inducing drugs (due to reduced efficacy)
- Unexplained vaginal bleeding (before evaluation)
POP are suitable for most women, including those with a higher risk of thrombosis.
Management of Incorrect Use
The cut-off to guide management differs slightly depending on the POP, but the management concept is the same:
- Traditional POP (levonorgestrel and norethisterone): 3-hour window
- Desogestrel POP: 12-hour window
Approach:
- If the pill is <3 hours late (levonorgestrel and norethisterone) or <12 hours late (desogestrel) → take the missed pill ASAP and no further action
- If the pill is >3 hours late (levonorgestrel and norethisterone) or >12 hours late (desogestrel) →
- Take the missed pill ASAP
- Use condoms or avoid sex for the next 48 hours
- Consider emergency contraception if UPSI occurred
Contraceptive Implant
The only contraceptive implant licensed in the UK is the etonogestrel implant (Nexplanon®)
Etonogestrel is a progesterone-only hormone.
Mechanism of Action
Primary action: inhibit ovulation
Route and Schedule
Subdermal implant in the upper non-dominant arm.
Inserted once and remains effective for 3 years.
Time Until Reliable Contraception
- If inserted on day 1-5 of the menstrual cycle → immediately effective (no additional protection needed)
- If started on any other days → use additional contraception (e.g. condoms) for 7 days (only effective after 7 consecutive days)
Adverse Effects
Adverse effects of the contraceptive implant are largely same as those of POP:
- Menstrual changes
- Irregular bleeding – most common
- Spotting
- Amenorrhoea
- Breast tenderness
- Acne
- Headache
Caution and Contraindications
Contraindications of the contraceptive implant are largely same as those of POP:
- Current breast cancer (UKMEC 4)
- Past breast cancer (within the past 5 years)
- Severe decompensated liver cirrhosis
- Use of enzyme-inducing drugs (due to reduced efficacy)
- Unexplained vaginal bleeding (before evaluation)
Injectable Contraception
Injectable contraception contains depo-medroxyprogesterone acetate (DMPA)
Mechanism of Action
Primary action: inhibit ovulation
Route and Schedule
There are 2 preparations of DMPA:
- Intramuscular DMPA: every 12 weeks
- Subcutaneous DMPA: every 12-13 weeks
Time Until Reliable Contraception
- If inserted on day 1-5 of the menstrual cycle → immediately effective (no additional protection needed)
- If started on any other days → use additional contraception (e.g. condoms) for 7 days
Adverse Effects
- Menstrual changes
- Irregular bleeding – most common
- Amenorrhoea
- Headache
- Acne
Important adverse effects that are significant in DMPA but not in other contraceptive methods:
- Weight gain – common (well-documented and more significant compared to other contraceptive methods)
- Delay in return to fertility (median 7-8 months after last injection)
- Reduction in bone mineral density (mostly reversible on discontinuation)
Caution and Contraindications
Important contraindications:
- Current breast cancer (UKMEC 4)
- Past breast cancer (within the past 5 years)
- Severe decompensated liver cirrhosis
- Unexplained vaginal bleeding (before evaluation)
- Known osteoporosis / significant fracture risk
- Current / history of ischaemic heart disease or stroke
- Current or recent VTE (not on anticoagulation)
- Multiple cardiovascular disease risk factors (e.g. smoking, diabetes, hypertension, dyslipidemia)
Levonorgestrel Intrauterine System (LNG-IUS)
Levonorgestrel is a progesterone-only hormone.
Mechanism of Action
Primary action: cervical mucus thickening
Route and Schedule
Intrauterine placement.
Inserted once and remains in place for:
- Up to 8 years (Mirena®)
- 6 years (Levosert®)
- 5 years (Kyleena®)
- 3 years (Jaydess®)
Time Until Reliable Contraception
- If inserted on day 1-5 of the menstrual cycle → immediately effective (no additional protection needed)
- If started on any other days → use additional contraception (e.g. condoms) for 7 days
Adverse Effects
LNG-IUS specific adverse effects
- Irregular bleeding and spotting – especially in the first 6 months
- Possible amenorrhea
LNG-IUS reduces bleeding, while copper IUD makes bleeding worse.
Other shared adverse effects of copper IUD:
- Risk of expulsion (1 in 20), more likely in first 3 months
- Risk of uterine perforation (rare, up to 2 in 1000)
- Risk of ectopic pregnancy (overall risk of ectopic pregnancy is reduced but if pregnancy does occur while using an LNG-IUS, there is a higher relative risk of it being ectopic)
- Risk of PID in first 20 days (after 20 days, risk of PID returns to baseline population levels
LNG-IUS have therapeutic benefits in heavy menstrual bleeding. It is 1st line for the management of heavy menstrual bleeding in those who do not want to conceive.
Caution and Contraindications
Important contraindications:
- Breast cancer (current is UKMEC 4 and past 5 years is UKMEC 3)
- Cervical or endometrial cancer (UKMEC 4)
- Unexplained vaginal bleeding (prior to evaluation) (UKMEC 4)
- Distorted uterine cavity (e.g. due to submucosal fibroids, intrauterine adhesions, large endometrial polyps, congenital uterine anomalies – typically seen on ultrasound / other imaging) (UKMEC 4)
- Current PID (UKMEC 4)
- Postpartum sepsis (UKMEC 4)
Copper Intrauterine Device (IUD)
Mechanism of Action
Primary action: copper ions are toxic to sperm → prevents fertilisation by reducing sperm motility and viability
Secondary action: inhibit implantation if fertilisation occurs
Route and Schedule
Intrauterine placement.
Various copper IUDs are available, they differ in shape, copper surface area and licensed duration of use:
- TCu380A: up to 10 years
- TT380 Slimline: up to 10 years
- Multi-load Cu375: up to 5 years
Time Until Reliable Contraception
Immediate effect upon insertion, no need for additional contraception.
Adverse Effects
Copper IUD-specific adverse effects
- Menstrual bleeding may become heavier, longer or more painful – especially in the first few months
LNG-IUS reduces bleeding, while copper IUD makes bleeding worse.
Other shared adverse effects of copper IUD:
- Risk of expulsion (1 in 20), more likely in first 3 months
- Risk of uterine perforation (rare, up to 2 in 1000)
- Risk of ectopic pregnancy (overall risk of ectopic pregnancy is reduced but if pregnancy does occur while using an LNG-IUS, there is a higher relative risk of it being ectopic)
- Risk of PID in first 20 days (after 20 days, risk of PID returns to baseline population levels)
LNG-IUS have therapeutic benefits in heavy menstrual bleeding. It is 1st line for the management of heavy menstrual bleeding in those who do not want to conceive.
Contraindications
| UKMEC 4 |
|
| UKMEC 3 |
|
Contraception by Clinical Scenarios
Postpartum Contraception
Contraception is needed after 21 days postpartum.
| Type of contraception | Description |
|---|---|
| Combined hormonal contraception (including COCP) | Breastfeeding postpartum:
Not breastfeeding postpartum:
|
| POP | Can be started immediately postpartum
(always UKMEC 1) |
| Contraceptive implant | Can be started immediately postpartum
(always UKMEC 1) |
| DMPA | Can be used safely postpartum
(no UKMEC 3 / 4) |
| LNG-IUS and copper IUD | Can be safely inserted (UKMEC 1) if:
Contraindicated if:
|
Contraception in Smokers
The only precaution is with CHC:
- Age ≥35 y/o + smoke ≥15 cigarettes / day: UKMEC 4
- Age ≥35 y/o + smoke <15 cigarettes / day: UKMEC 3
- Age ≥35 y/o + stopped smoking <1 year: UKMEC 3
UKMEC 1 for all other contraceptive methods, regardless of age and quantity of smoking.
Contraception in Obese Individuals
The only precaution is with CHC:
- BMI ≥35 kg/m2: UKMEC 3
- BMI 30-34 kg/m2: UKMEC 2
UKMEC 1 for all other contraceptive methods, regardless of BMI.
Contraception in Oestrogen-sensitive Cancers (e.g. breast cancer)
All hormonal methods are UKMEC 4 (for current breast cancer) and UKMEC 3 (for past breast cancer).
Only UKMEC 1 is a copper IUD.
Contraception and Enzyme-Inducing Antiepileptic Drugs
The only UKMEC 1s are:
- LNG-IUS
- Copper IUD
- DMPA injection
All other contraceptive methods are UKMEC 3.
Contraception in Hypertension
The 2 implicated contraceptive methods are CHC and DMPA.
CHC contraindications:
- UKMEC 4: BP ≥160/100 mmHg and presence of vascular disease
- UKMEC 3: BP ≥140/90 mmHg (even if adequately controlled)
DMPA contraindications:
- UKMEC 3 if there is vascular disease
Contraception in VTE
The only precaution is with CHC:
- UKMEC 4 if
- History or current VTE
- Major surgery with prolonged immobilisation
- UKMEC 3 if
- 1st degree relative <45 y/o with VTE
- Immobility (unrelated to surgery) (e.g. wheelchair use, debilitating illness)
All other contraceptive methods are UKMEC 1 or 2.
References
FSRH UK Medical Eligibility Criteria for Contraceptive Use (UKMEC)
FSRH CEU Guidance: Recommended Actions after incorrect Use of Combined Hormonal Contraception