Contraception Flashcards
How is basal body temperature measured in order to calculate fertility?
Taken before rising in morning
Increase in body temp > 0.2oC
Sustained for 3 days after at least 6 days of lower temp
how does cervical position relate to fertility?
When fertile….
Cervix is high in vagina, soft and open
When less fertile….
Cervix is low in vagina firm and closed
which days in a standard cyle are most fertile?
Days 8 to 18 are most fertile
which three criteria make breast feeding 98% successful as a contraceptive
1) exclusively breast feeding
2) less than 6/12 post natal
3) amenorrhoeic
describe the 4 UKMEC categories
1) No retrictions
2) Advantages outway risks
3) risks outway advantages
4) unacceptable risk
difine LARC
Long-acting reversible contraceptives (LARC) are methods of birth control that provide effective contraception for an extended period without requiring user action. They include injections, intrauterine devices (IUDs) and subdermal contraceptive implants.
How does Depo Provera work?
Primary action:
Inhibits ovulation
Other effects:
Effect on cervical mucus
Effect on endometrium
Failure rate -pearl index 0.3%
what examinations need to be down befroe depo provera?
Record BP (must be lower than 140/90) and BMI before first prescription
Check smear status if relevant
Consider risk factors for osteoporosis
Are there multiple risk factors?
when can depo provera be started?
Standard Advice – Depo can be started up to and including Day 5 of the cycle without the need for any additional contraception
Beyond Day 5 a woman can start the depo at any other time provided she is ‘reasonably certain’ she is not pregnant and use condoms/abstinence for 7 days
what are the side effects of depo provera?
Weight gain
Delay in return of fertility
Irregular bleeding
Possible risk of osteoporosis
how often do you need depo provera injections?
every 12 weeks
How does the LARC- IUD work?
T shaped device usually containing copper
Primary mode action:
Prevention of fertilisation
Inflammatory response in endometrium
Licence 5/10 yrs
Failure rate pearl index 0.5% (1/200)
How does the IUS work
T shaped device with elastomere core. Emits levanorgestrel
Primary mode of action:
Effect on implantation
Endometrium rendered unfavorable for implantation
Also effect on cervical mucous and pre-fertilisation effects
Failure rate pearl index 0.2%- (approx 1/500)
what exams are down before iserting a IUS?
PV to check uterine size/ position
BP and pulse if condition indicates
when can IUDs and IUSs be fitted
Within in the first 7 days of a period
Any time provide reasonably certain not pregnant
Up to 5 days after UPSI ( for EC) (IUD ONLY)
OR
Up to 5 days after predicted date of ovulation
Either within 48 hrs or > 4 weeks post partum
Immediately post TOP ( if products of conception seen)
if an IUS is fitted outwith menstruation what precautions should be taken?
condoms for first 7 days
what are the complications of IUDs and IUSs?
Lighter, less frequent bleeding (IUS) Heavy prolonged menses (IUD)
Pain, infection PID increased in first 20 days
Perforation 1-2/1000
Expulsion- same as IUD
what is in the implant? How long is it licensed for?
What are it’s modes of action?
Subdermal rod
Licence 3 yrs
Contains 68mg ENG
Primary mode of action:
Inhibition of ovulation
Other mechanisims:
Effect on endometrium
Effect on cervical mucus
Failure rate - pearl index 0 to 0.1%
when can an implant be fitted?
No need for additional precautions:
Within first 5 days of cycle
Up to day 5 post first/second trimester abortion
On or before day 21 postpartum
Need for additional precautions first 7 days
If it is reasonably certain she is not pregnant
“quick start” after emergency contraception
Off licence
what are the complications of an implant?
Irregular bleeding
Wt gain
Acne
Nerve damage/ vascular injury
Deep insertion
describe a standard regime of Combined Oral contraception
- Take daily for 21 days then stop for 7 days during which a withdrawal bleed occurs due to shedding of the endometrium
- The first 7 pills taken inhibit ovulation and the remaining 14 pills in the pack maintain anovulation
- Follicular activity may resume after 9 pills have been omitted
describe a standard regime of a combined transdermal patch
•One patch is applied and worn for 1 week to suppress ovulation. Thereafter the patch is reapplied weekly for a further 2 weeks. The fourth week is patch-free to allow a withdrawal bleed. A new patch is applied after 7 patch-free days
describe the standard regime of a vaginal ring
•A ring is placed into the vagina and left continuously for 21 days. After a ring-free interval of 7 days to induce a withdrawal bleed, a new ring should be inserted
describe some of the off-licenc tailored regimes
- Tri-cycling – 3 ‘packs’ taken back to back then 7 days off
- Shortened hormone free interval – 3 weeks of CHC use then 4 days off
- Extended use – method used continuously until breakthrough bleeding occurs then stop for 4 or 7 days
how do the CTP, COC and CVR compare to each other?
- CTP – more breast pain, nausea, painful periods than COC/CVR
- CVR – less bleeding problems, acne, irritability/mood changes
When can you start chc?
Standard Advice – COC’s can be started up to and including Day 5 of the cycle without the need for any additional contraception
Beyond Day 5 a woman can start the COC at any other time (off licence) provided she is ‘reasonably certain’ she is not pregnant and use condoms/abstinence for 7 days – ‘quick start
what contraception should be used after ec?
condoms
- Levonelle 1500 (progestogen) – abstain/condoms 7 days
- Ulipristal Acetate (anti-progesterone) - hormonal contraception interferes with action of Ulipristal Acetate
- avoid starting contraception for 5 days
what do you do if you miss a pill?
What if I’ve missed one pill?
If you’ve missed one pill anywhere in the pack or started a new pack one day late, you’re still protected against pregnancy. You should:
take the last pill you missed now, even if this means taking two pills in one day
carry on taking the rest of the pack as normal
take your seven-day pill-free break as normal or, if you’re on an Every Day (ED) pill, take your inactive (dummy) pills
You don’t need to use extra contraception.
What if I’ve missed two or more pills?
If you’ve missed two or more pills anywhere in the pack or started a new pack two or more days late (48 hours or more), your protection against pregnancy may be affected. You should:
take the last pill you missed now, even if this means taking two pills in one day
leave any earlier missed pills
carry on taking the rest of the pack as normal
use extra contraception such as condoms for the next seven days
When you start your next pack after missing two or more pills:
if there are seven or more pills left in the pack after the last missed pill, finish the pack, take your seven-day pill-free break as normal, or take your inactive pills before you start your next pack
if there are fewer than seven pills left in the pack after the missed pill, finish the pack and start a new pack the next day (this means missing out the pill-free break or not taking your inactive pills)
If you’ve had unprotected sex in the previous seven days and you’ve missed two or more pills in the first week of a pack, you may also need emergency contraception.
what is the mechanism of pop?
Primary mechanism
- Thickening of cervical mucous
- Etonorgestrel – suppression of ovulation in up to 97% of cycles
Secondary
- Suppression of ovulation in up to 60% of cycles (Levonorgestrel)
- ê endometrial receptivity to blastocyst
- Reduction in cilia activity in fallopian tube
what happens if you miss one POP?
•One missed dose plus UPSI
= emergency contraception plus 2 days extra protection
what are the risks and unwanted effects of chc?
- Venous thrombosis
- Arterial thrombosis
- Adverse effects on some cancers
- Systemic hypertension
COC use shows a small
increase in blood pressure
in some individuals.
Must therefore check initially,
at 3 mths then annually
•140/90
Risk of VTE in COC users is increased over non-users and varies according to EE dose and progestogen type
Risk is low but will affect individuals with other risk factors for VTE
what are the risks for VTE?
- Obesity
- Smoking
- Age
- Known thrombophilia
- VTE in first degree relative < 45 yrs
- Up to 6 weeks postnatal
- Trekking > 4,500 m for > 1 week
- Long-haul flights
- Reduced mobility
- Antiphospholipid syndrome
- Other conditions causing increased VTE risk
which acne treatment can also be used as a contraceptive?
Cyproterone Acetate
Would you prescribe CHC to someone with aa migraine with an aura?
- Migraine with aura increases the risk of ischaemic stroke
- CHC use in individuals with
migraine with aura further increases
the risk of stroke and is
contraindicated
