15) Sexual & Reproductive Health - Contraception Flashcards
(113 cards)
Proportion of women using oral contraception in last year
1/3
Different generations of progestogens in CHC
First generation: Norethisterone
Second generation: LNG
Third generation: Desogestrel, gestodene, norgestimate
Other: Drospirenone, dienogest, nomegestrol
Main mechanism of action of combined hormonal contraceptives
Prevention of ovulation
When to start CHC?
(1) D1-D5 of natural menstrual cycle (or D1-D5 post early pregnancy loss) without additional precautions
(2) “Quick start” at any other time (with additional precautions for 7 days) provided reasonably certain not pregnant OR UPT is negative and follow up UPT done 21 days after UPSI.
When to start CHC after EC?
Immediately after Levonelle.
5 days after EllaOne.
How to switch to CHC from another method?
- From another CHC: Start on day after last active dose.
- Desogestrel POP: Start immediately with no additional precautions
- Traditional POP: Start immediately but need additional precautions 7d
- Mirena: Start any time but use additional contraception for 7d.
- Cu-IUD: Up to D5 of menstrual cycle without precaution or any time with 7d additional precautions
Effectiveness of COCP
- Perfect use: 0.3% failure
- Typical use: 9% failure
When is a COCP classed as missed?
If not taken in 24h after it should have been
Effect of enzyme inducing drugs on CHC
Reduced effectiveness for duration of treatment and up to 28 days after
Interaction of lamotrigine and CHC
Lamotrigine may be less effective
Advice re: D&V with CHC
Follow “missed pill” advice if vomiting occurs within 3 hours of COC or severe diarrhoea occurs for 24 hours.
“Missed pill” advice for COCP, vaginal ring and patch
(1) If late restarting HFI (any number of pills, ring, patch):
- Emergency contraception if UPSI during HFI
- Take most recent missed pill and then continue pills at usual time
- Additional precautions for 7 days
- Consider 3/52 PT
(2) If miss pills during week 1:
ONE PILL ONLY/RING removed <48h/PATCH <48h:
- No EC required
- Take most recent missed pill and then continue pills at usual time
- No additional precautions required
TWO OR MORE PILLS/RING removed >48h/PATCH >48h:
- Emergency contraception if UPSI during HFI/week 1
- Take most recent missed pill and then continue pills at usual time
- Additional precautions 7 days
- Consider 3/52 UPT
(3) If miss pills during week 2/3:
ONE PILL ONLY/RING removed <48h/PATCH <48h:
- No EC required
- Take most recent missed pill and then continue pills at usual time
- No additional precautions required
TWO OR MORE PILLS/RING removed >48h/PATCH >48h:
- No EC required
- Take most recent missed pill and then continue pills at usual time
- Additional precautions 7 days
- If during week 3 - omit HFI
Precautions for accidental continued use of the same combined hormonal vaginal ring beyond 3 weeks
3-4 WEEKS:
- EC not required if ring consistently in place D21-D28
- Start HFI or insert new ring
- No additional precautions required
4-5 WEEKS:
- EC not required if ring consistently in place D21-D28
- Omit HFI and insert new ring
- Additional precautions 7 days
> 5 WEEKS:
- EC if UPSI during week 5 or later
- Omit HFI and insert new ring
- Additional precautions 7 days
- Follow up UPT
What percentage of women experience breakthrough bleeding with CHC?
10-20% per cycle which is likely to improve over first 3-4 months.
Return to fertility with CHC
99% return to spontaneous menstruation (or become pregnant) within 90 days of stopping CHC. Majority ovulate within 1 month.
1st line COCP
<30 microgram ethinylestradiol with LNG/NET
Risk of VTE with CHC
- Risk is increased 3-5 fold
- Non-users 2 per 10,000/year. CHC 5-12 per 10,000/year.
- Lower than pregnancy!
- Highest in months immediately after insertion or when restarting after break > 1 month (risk reduces over first year of use and then remains stable)
Effect of progestogen type on VTE risk
No CHC: 2 per 10,000 per year
LNG/NET/norgestimate: 5-7 per 10,000
Etongestrel/norelgestromin: 6-12 per 10,000
Drospirenon/gestodene/desogrestrel/co-cypindiol: 9-12 per 10,000
Risk of arterial thromboembolic disease with CHC
- Increased risk of MI and ischaemic stroke
- Risk higher with increased oestrogen doses but does not vary according to progestogen type
Risk of breast cancer with CHC
- Current use carries small increased risk (RR 1.2) which reduces with time after stopping (normal by 5 years)
Risk of cervical cancer with CHC
- Current use for >5 years associated with increased risk which reduces after stopping and is normal at 10 years
Advice for CHC and altitude
Avoid if spending > 1 week at altitude > 4500m
Advice for CHC and major surgery
Switch method at least 4 weeks prior to planned major surgery or expected period of limited mobility
Efficacy of male and female condoms
Male condoms: Perfect use 2% failure, typical use 18% failure
Female condoms: Perfect use 5% failure, typical use 21%