Flashcards in Contraception Deck (85):
What is involved in natural family planning?
Basal body temperature
When is basal body temp taken and what are the characteristics of it?
Before rising in morning
Increase in temp of >0.2'C
Sustained for 3 days after at least 6 of lower temp
Describe cervical mucous
Thick and sticky post ovulation
At least 3 days after thinner, watery, stretchy mucous
What is meant by cervical position?
When fertile, cervix is high in vagina, open and soft
When less fertile, cervix is low in vagina, firm and closed
What are standard days?
In a 28 day cycle, days 8-18 are the most fertile
How can breast feeding be used as a form of birth control?
3 criteria needed:
Exclusively breast feeding
Less than 6/12 post natal
What are the 4 UKMEC categories for contraception?
1. No restriction for the use of the contraceptive method
2. Where the advantages of using the method generally outweigh the theoretical or proven risks
3. A condition where the theoretical or proven risks generally outweigh the advantages of using the method.
4. A condition which represents an unacceptable risk if the contraceptive method is used
What is the Pearl index?
Represents no. of contraceptive failures per 100 women users/year
No. of accidental pregnancies x 1200
What LARC exists in the UK?
Injectable contraceptive: Depo provera/Sayana press
How does Depo provera/Sayana press work?
Given every 13 weeks, will last 14
Other effects on cervical mucus and endometrium
What examination should be done prior to contraception prescription?
RFs for osteoporosis
What are the risk factors for osteoporosis?
Prolonged steroid use
XS alcohol intake
Low trauma fracture
What chronic conditions increase the likelihood of osteoporosis?
Chronic renal disease
When can depo be started?
Up to and including day 5 of cycle without need for additional contraception
Beyond day 5, depo can be started but condoms must be used for 7 days, and reasonably certain of not pregnant
What is defined as reasonably certain of not currently pregnant?
No sex since last period
Consistently using reliable contraception
<7days since last normal period
<4 weeks post partum
Fully breastfeeding, amenorrhoeic and <6m post partum
-ve preg test
>3 wks since UPSI
When can Depo be started post partum and post TOP?
Postpartum: Up to day 21 with immediate cover
Post TOP: Up to day 5
What are some side effects of Depo?
Delay in return of fertility
Risk of osteoporosis
Copper and plastic
Prevents fertilisation- inflammatory response in endometrium
Effects on implantation-endometrium rendered unfavourable
Also on mucus and pre-fertilisation
What are the two types of IUS?
52mg LNG-IUS (MIRENA®)
20 mcg levonorgestrel daily
Decreasing to 10ug per day a 5 yrs
13.5mg LNG-IUS (Jaydess®)
14ug per day for first 24 days
Decreasing to 5ug per day at 5 yrs
What contraindicates IUD/IUS?
Current pelvic infection
Abnormal uterine anatomy
Sensitivity to any of the constituents
Gestational trophoblastic disease when BHCG levels are abnormal/persistently elevated
Cervical ca awaiting treatment
What examination should be done prior to IUD/IUS?
PV to check uterine size/position
When can an IUD be fitted?
Within first 7 days of period
Anytime provided reasonably certain not pregnant
Up to 5 days after UPSI (for emergency contraception)
Up to 5 days after predicted date ovulation
Either within 48hours or >4 weeks post partum
Immediately post TOP (if products of conception seen)
When can an IUS be fitted?
Within first 7 days of period
Anytime provided reasonably certain not pregnant
Not used for EC
If fitted within first 7/7, use condoms for 7/7
Either within 48 hrs or >4wks post partum
Immediately post TOP (products of conception seen) up to day 7
What are the side effects and problems associated with IUD?
Heavy, prolonged menses
Pain, infection PID increased in first 20days
Higher post 2nd trim abortion
What are the side effects and problems associated with IUS?
Lighter, less frequent bleeding
Pain, infection PID increased in first 20 days
What is the implant?
Single, non biodegradable subdermal rod
3 years licence
Contains 68mg ENG, releases 60/70ug/day in weeks 5-6, 25-30ug/day by end of 3 years
How does the implant work?
Inhibition of ovulation
Also effect on endometrium and cervical mucus
When can the implant be fitted?
No need for precautions: first 5 days of cycle, up to day 5 post 1st/2nd trim abortion, on or before day 21 post partum
Precautions first 7 days: if reasonably certain not pregnancy, quick start after EC, off-licence
When can the implant be fitted post CHC/depo and COC, patch or vaginal ring?
COC/patch/vaginal ring: week 2-3
When switching from another method, when are additional precautions needed in the first 7 days?
Changing from POP or LNG-IUS
Switching from non-hormonal method
What are the side effects of the implant?
Are there any general health concerns with the implant?
No known effect on BMD, CV risk, VTE risk, MI risk
What are the non-contraceptive features that CHC can benefit/improve?
Heavy menstrual bleeding
Menstrual migraine (no aura)
What are the 3 types of CHC, and their drug doses?
COC- 20-35μg EE
Combined transdermal patch- 33μg EE
Combined vaginal ring- 15μg EE
What medications are used in CHC?
Oestrogen (ethinyl estradiol (EE))
What is the mode of action of CHC?
Inhibiting ovulation via action on HPO axis to reduce LH/FSH
Also alters cervical mucus, and renders endometrium unfavourable for implantation
What is the efficacy of CHC?
Perfect use: 0.3%
If a patient using CTP is >=90kg, what may this cause?
Decreased efficacy- use alternative
What is the standard regime for COC?
Take daily for 21 days, then stop for 7 (withdrawal bleed occurs)
First 7 pills inhibit ovulation, remaining 14 pills maintain anovulation
When will follicular activity resume following COC?
After 9 pills have been omitted
What is the standard regime for CTP?
One patch applied and worn for 1 week to suppress ovulation
Reapplied weekly for further 2 weeks
4th week is patch free (withdrawal bleed), new patch worn thereafter
What is the standard regime for CVR?
Ring placed in vagina and left continuously for 21 days
Ring free interval of 7 days for withdrawal bleed, then new ring
What are some tailored off licence regimes for CHC?
Tri cycling- 3 packs back to back then 7 days off
Shortened hormone free interval, 3 weeks on 4 days off
Extended use- continuous until breakthrough bleeding, then stop for 4 or 7 days
What factors require consideration for safe prescribing of CHC?
What factors may affect effectiveness of CHC?
Impaired absorption- GI conditions
Increased metabolism-liver enzyme induction
What should you do when you miss one COC pill?
Over 24 hours and less than 48 hours without pill
Take the missed pill as soon as it is remembered
Remaining pills are taken at the normal time
EC is not required
What should you do when you miss two or more COC pills?
More than 48 hrs without pills
Take the most recent missed pill
Take the remaining pills at the correct time
Use condoms or abstain until 7 pills have been taken consecutively
To minimise the risk of pregnancy, what can be done if more than 48 hours without pills?
Days 1-7: Consider EC
Days 8-14: No extra instructions
Days 15-21: Omit pill free interval
Low threshold for EC and bicycling packets
What happens regarding removal of a CTP?
Can remain off for up to 48 hours before efficacy reduced
How long can the patch be worn or the patch free interval be extended by before efficacy is reduced?
7 days + 48 hours
Though if interval, EC may be needed
How long can the CVR be left out of vagina before efficacy reduced?
How long can the CVR be worn for before efficacy reduced?
Up to 4 weeks
How long can the ring free interval be extended by without efficacy reduced?
What are some risks of CHC?
Adverse effects on some cancers
What are some metabolic effects of CHC?
Alteration in clotting factor levels induced by EE may be thrombogenic eg reduces levels of antithrombin III and protein S
In patients with significant arterial wall disease EE may also promote superimposed arterial thrombosis
There is increased fibrinolytic activity but reversed in heavy smokers
What are some risk factors for VTE with regards to contraception?
VTE in first degree relative < 45 yrs
Up to 6 weeks postnatal
Trekking >4500m for >1wk
What can co-cyprindiol be used for?
Acne and hirsutism treatment- not licenced contraception but acts as contraceptive
What makes up co-cyprindiol?
Ethinyl-estradiol 35μg/cyproterone acetate
What CHCs have the lowest risk of VTE?
CHCs that contain levonorgestrel, norethisterone, or norgestimate
What are some circulatory effects from COC?
Systemic HT, therefore must check initially at 3 months then annually
Arterial disease- risk of MI- especially smokers, ischaemic stroke
CHC use in individuals with migraine with aura further increases the risk of what?
Stroke, therefore contraindicated
What UKMEC category is BRACA?
If you have a personal or family history of breast cancer, what does this mean for contraception?
Personal: CHC contraindicated
FHx: UKMEC 1
CHC can increase the risk of cervical cancer with what use?
Long term of >5yrs, reduces to baseline 10y after stoppign
What cancers have CHCs been shown to provide protection against?
Ovarian and endometrial- benefit may last decades after CHC use
Do all CHCs show a beneficial effect on acne?
What conditions/problems can benefit from CHC?
Functional ovarian cysts
What are some S/Es of CHCs?
Unscheduled bleeding- usually settles by 3 months
Mood changes- no evidence for depression
Weight gain- no strong evidence
What side effects does CTP have compared to COC?
More breast pain
Painful periods compared to COC/CVR
What side effects does CVR have compared to COC?
Less bleeding problems
When can you start CHC?
Up to and including day 5 of cycle without precautions
Beyond this, anytime off licence provided reasonably certain not pregnant and uses condoms for 7 days
What should be used after EC?
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
If pregnancy cannot be excluded, how should CHC be started?
Quick start and do PT in 4/5weeks (outwith licence, but guidelines support)
What are the types of POP?
Traditional: levonorgestrel, norethisterone
Newer: etonorgestrel- longer lasting
What is the MOA of POP?
Thickening of cervical mucous
Etonorgestrel – suppression of ovulation in up to 97% of cycles
Also suppression of ovulation in up to 60% (levonorgestrel)
Decreased endometrial receptivity to blastocyst
Reduction in cilia activity in fallopian tube
What are the risks of POP?
Little effect on metabolism
Given in most circumstances
Safer than pregnancy, so UKMEC 3
UKMEC 4: Current breast cancer
What can POP's interact with?
Liver enzyme inducers-cytochrome P450
Suitable alternatives needed, effect continues for 28 days after stopping
How are traditional POPs taken?
Daily at same time, no break
Within 24-27hours of last dose
How are newer POPs taken?
Daily at same time within 24-36hrs of last dose
What should you do if you miss 1 dose of POP and have UPSI?
EC plus 2 days extra protection
What is the efficacy of POPs?
Etonorgestrel- more effective
How is vasectomy carried out?
What is the P.I. of vasectomy?
0.1% (0.05 after clearance given)