contraception Flashcards
contraceptive methods available in UK
combined hormonal contraception (CHC), pill or patch - 25%
progesterone only pill (POP) - 5%
progesterone only implants/injection - 5%
intrauterine methods - 6%
sterilised (M/F) - 28%
what makes the ideal contraceptive
100% reversible 100% effective unrelated to intercourse free of adverse side effects protective against STIs non-contraceptive benefits low maintenance, no ongoing medical input male and female options
how can the effectiveness of contraceptive be descreibed
pearl index - number of pregnancies per 100 women within the first year of use
looks at the total mths/cycles of exposure from the initiation of the product to the end of the study
life table analysis provides the pregnancy rate over a specified time frame and can provide a cumulative failure rate for any specific length of exposure
LARC
long acting reversible contraception - less user input therefore minimises user failure rates
injection, implant, copper IUD, IUS
what is method failure
pregnancy despite correct use of method
what is user failure
pregnancy because method not used correctly
when can sex cause pregnancy
if 26-32 day cycle and no on hormonal Rx:
likely to ovulate day 12-18
egg survives 24hrs
most sperm survive <4days (5% up to 7days)
highest chance of pregnancy = sex on day 8-19
why can natural methods of contraception fail
sperm survival and ovulation timing after last period is variable
even w/ abstinence or barrier options on fertile days as predicted from usual cycle, natural methods can fail
use
what is within combined hormonal contraception
ethinyl estradiol (EE) synthetic progesterone
what does CHC do
stops ovulation
also affect cervical mucus and endometrium
standard regime for CHC
21 days w/ hormone free week
sex is safe in pill free week - must remember to start new pack
tailored regimes for CHC
tricycling/continuous use
no need for uncomfortable inconvenient withdrawal bleed
avoids forgetting to restart after break
types of CHC
pill
patch
vaginal ring
pill CHC
taken daily, anytime within 24hrs
not good if frequent GI upset - may not be absorbed properly
patch CHC - EVRA
changed weekly
applied to hairless skin, not breast area
<5% have skin reaction
ring CHC - nuvaring
changed every 3wks
can take out for 3hrs in 24
may prefer to take out for sex
non-contraceptive benefits of combined hormonal methods
regulate/reduce bleeding
stop ovulation - may help premenstrual syndrome
reduction in functional ovarian cysts
50% reduction in ovarian and endometrial cancer
improve acne/hirsutism
reduction in benign breast disease, rheumatoid arthritis, colon cancer and osteoporosis
side effects of CHC
breast tenderness
nausea
headache
irregular break thorugh bleeding in first 3mths
may effect mood - causal relationship or other life events?
weight gain - not causal
serious risks of CHC
increased risk venous thrombosis - DVT, PE
increased risk artherial thrombosis - MI, ischaemic stroke
increased risk cervical cancer - data predates HPV vaccine
increased risk breast cancer
who shouldn’t be using CHC
PE/DVT RISK: BMI>34, previous VTE, 1st degree relative VTE <45y/o, reduced mobility, thrombophilia (e.g. SLE)
MI/STROKE RISK: smokers >35 y/o, personal hx arterial thrombosis, focal migraine, >50y/o, HT >140/90
active gall bladder disease/prev liver tumour
breast cancer and CHC
back to normal after 10yrs off Rx, avoid if prev breast cancer
non BRCA FHx breast cancer not a CI
risk of VTE w/ CHC
risk increases from:
2/10 000 p/a in general pop
5-7/10 000 p/a w/ COC use (LNG and NET progesterone)
6-12/10 000 w/ patch/ring/COC other progesterone use
50/10 000 w/ pregnancy
pill increases risk 3x - overall risk is still small
need VTE prophylaxis if inpatient/surgery/immobile
progestogen only pill (POP) - how to take
same time every day w/o pill free interval
not good choice if frequent GI upset - poor absorption
types of POP
desogestrel pill
traditional LNG NET pills
desogestrel pill
12hr window period
nearly all cycles anovulant - also affect mucus
most users bleed free after 1st 4-6mths
traditional LNG NET pills
3hr window period
1/3 anovulant
2/3 rely on cervical mucus effect
1/3 bleed free, 1/3 irregular, 1/3 regular periods
CI for POP
oestrogen free so very few CI
personal Hx breast cancer (current) or liver tumour (past/present)
POP side effects
appetite increase hair loss/gain mood change bloating/fluid retention headache acne
risk of VTE/aterial thrombosis on POP
no increased risk with contraceptive doses of progestogen
injectable progestogen
medroxyprogesterone acetate
dose every 13wks
site of progestogen injection
1ml deep IM injection
upper outer quadrant of buttok - depoprovera
0.6ml SC injection abdo/thigh, possible self administration - Sayana press
how does the progestogen injection work
prevents ovulation
alters cervical mucus - hostile to sperm
endometrium unsuitable for implantation
benefits of progestogen injection
only need to remember every 12-14wks
70% amenorrhoeic after 3 doses
oestrogen free - few CI
disadvantages of progestogen injection
delay in return to fertility - ~9mths
reversible reduction in bone density - discuss other risks for osteoporosis
problematic bleeding - esp after 1st 2 doses
weight gain - 2/3 of women 2-3kg
what is the only contraceptive method with a causal effect on weight gain , delayed return of fertility and bone density
progestogen injection
subdermal implant - nexplanon - contents
small plastic rod, 4cm long
core - 68mg etonogestrel (ENG)
membrane - ethinyl vinyl acetate (EVA), rate controlling
progestogen implant effects
inhibition of ovulation
effect on cervical mucus
benefits of progestogen implant
can last 3 yrs, can be removed at any time
no user input needed
no causal effect on weight change
60% are almost bleed free
disadvantages of progestrogen implant
30% have prolonged/frequent bleeding
causes mood change more often than other progestogen only methods
how long does intrauterine contraception last
5-10yrs
benefits of intrauterine contraception
little user input after fitting, can check own threads
can be fitted for any age and any parity
effects/side effects immediately reversible when removed
risks of intrauterine contraception
very small infection risk in first 3wks (<1:1000) - offer STI testing to all w/ new partner or <25y/o
1:1000 risk perforation
5:100 risk expulsion - check threads after every period
higher risk of ectopics, method is so effective that ectopic risk lower than for condoms
who cannot have intrauterine contraception
untreated pelvic infection
distorted endometrial cavity e.g. submucous fibrouds/bicornuate/previous ablation
mode of action of copper IUD
toxic to sperm
stop sperm reaching egg
may sometimes work by preventing implantation of fertilised egg
advantages of copper IUD
hormone free
can last 5-10yrs depending on type
device fitted after 40y/o can work until menopause
not CI to MRI
disadvantages of copper IUD
may make periods heavier/crampier
levonorgestrel IUS effects
affects cervical mucus and endometrium
most women still ovulate
stops fertilisation of egg
may prevent implantation of fertilised egg
release of progestogen in levonorgestrel IUS
slow release progestogen on stem
low circulating levels compared w/ pill/implant/injection
effect of IUS on menstrual bleeding
reduce bleeding after up to 4mths initial irregular bleeding
Mirena IUS - how long does it last
5yrs contraception (if fitted >45y/o effective till 55)
Mirena IUS - effect on bleeding
85% almost bleed free by 12mths
Mirena IUS - dose
equivalent systemic dose to 3 POP/wk
other uses for Mirena IUS
licensed to treat heavy menstrual bleeding
can act as the progestogenic part of HRT for 5yrs
Kyleena IUS - how long does it last
5yrs
Jaydess IUS - how long does it last
3yrs
benefits of Kyleena/Jaydess USS
less progestogen so even less chance of side effects BUT less likely to be bleed free
smaller frame and insertion tube
what are the 3 types of emergency contraception
most effective - copper IUD levonorgestrel pill (Levonelle) Ulipristal pill (Ellaone)
Copper IUD emergency contraception
fit before implantation - within 120hrs of unprotected sex at any point of cycle OR by day 19 of 28 day cycle
can keep long term if working well
<1 pregnancy for 100 women using it
levonorgestrel pill (Levonelle) emergency contraception
take within 72hrs
2-3 pregnancies for 100 women
Ulipristal pill (Ellaone) emergency contraception
take within 120hrs
more CI e.g. breastfeeding/enzyme inducing drugs
1-2 pregnancies for 100 women
when to start contraception
immediate cover if started in first 5days of cycle
can start at other points in cycle if no risk of pregnancy (need condoms/abstain for next 7 days AND do pregnancy test after 4wks)
how soon after delivery can you become pregnanct
from 21days after delivery
5 days after miscarriage or abortion
for how long is breastfeeding contraceptive
only for first 6mths AND feeding every 4hrs AND amenorrhoeic
a breastfeeding woman can use any type pof contraception - wait 6wks before CHC
contraception and drug interactions
enzyme inducing drugs increase the metabolism of progestogen and oestrogen and reduce the effectiveness of combined pill, patch, ring and POP and the implant
progestogen injections and copper IUD/levonorgestrel IUS are not affected
examples of enzyme inducing drugs
carbamazepine
topiramate
rifampicin
St John’s Wort
how is female sterilisation normally carried out
laparoscopic
usually Filshie clips applied across tube to block tube lumen
metal/silicone
not CI for MRI
effects of female sterilisation
risks of GA and laparoscopy
irreversible - risk regret
failure rate 1/200 in lifetime - could be ectopic
does female sterilisation effect periods/hormones
no
female sterilisation and ovarian cancer risk
reduces risk
even more reduction if salpingectomy but this is a more complex surgery
when can a salpingectomy be carried out
at planned C section if baby seems well and discussed in advance
what is a salpingectomy
surgical removal of one or both fallopian tubes
vasectomy procedure
local anaesthetic, most done in 1y care
small incision midline scrotum
vas deference divided
ends cauterised
how long does a vasectomy take to become effective
4-5mths
2 sperm samples sent in by post after 4 and 5 mths
failure rates 2/100 do not get clear samples
failure rate of vasectomy
after 2x clear samples
1/2000
is a vasectomy reversible
irreversible
anti-sperm antibodies even if vas reconnecte
side effects of vasectomy
<1:100 risk long term testicular pain
effects of vasectomy on other functions and cancer risk
no effects on testosterone or sexual function
no increased risk of testicular/prostate cancer
stats for abortion
1/3 women in UK most common 20-24y/o numbers falling, esp in 20s 90% under 12 wks linked to deprivation
types of contraception in use by women at TOP clinic
condoms - most common
unprotected sex (UPSI) - only 10% of these took emergency contraception
pills
LARC
what is TOP
termination of pregnancy
rights and responsibilities of clinicians regarding TOP
right to refuse participation in abortion because they have a conscientious objection to the procedure
obligation to ensure that the woman is still able to access abortion care
right to refuse participation as long as this doesn’t affect any duty to participate in treatment which is necessary to save the life/prevent grave permanent injury to the physical/mental health of a pregnant woman
1967 abortion act
2 Drs sign
Continuing the pregnancy has grave risk to the life of the pregnant woman- greater than if pregnancy terminated
Termination is necessary to prevent grave permanent injury to the physical or mental health of the pregnant woman
Under 24 weeks and continuation of pregnancy involves risk greater than if the pregnancy were terminated of injury to the physical or mental health of the pregnant woman
Under 24 weeks and continuation of pregnancy involves risk greater than if the pregnancy were terminated of injury to the physical or mental health of the existing child (ren) of the pregnant
There is a substantial risk that if the child were born it would suffer physical or mental abnormalities as to be seriously handicapped
TOP clinic consultation
medical Hx - risk VTE/bleeding/from GA/contraceptive eligibility
circumstances - reason for considering abortion, support see alone/language line, check no coercion
usually need scan to confirm gestation and viable IUP
discuss methods of abortion
risks
contraception for afterwards
risks of abortion
infection <10%
blood transfusion <1:1000
investigations before abortion
FBC/rhesus group >10wks or STOP +/- heamoglobinopathy
vaginal swab for chlamydia, gonorrhoea, TV
STI bloods offered - BBV, syphilis
long term effects of abortion
safer than a full term delivery
no effect on future fertility unless infection/perforation
no effect on cancer risks
emotional effects - depend on reasons for abortion, pre-existing mental health issues
when is surgical termination of pregnancy carried out
5-12wks
procedure - surgical termination of pregnancy
cervical priming - misoprostol 3hrs preop, helps dilation, reduces risk of perforation/haemorrhage
GA/LA cervical block
transcervical - 6-10mm suction catheter
<10 mins
complications of surgical termination of pregnancy
1-4:1000 perforation
<1:100 cervical injury
risks from GA
when is medical termination of pregnancy carried out
5-23+5wks
medical termination of pregnancy procedure
mifepristone - oral antiprogestogen tablet
36-48hrs later misoprostol initiates uterine contraction which opens cervix and expels pregnancy
avg 4-6hrs to pass pregnancy <12wks
complications of medical termination of pregnancy
failure 1/100 <8wks, 8:100 >12wks
need surgery for incomplete abortion
early medical abortion at home
legal to supply misoprostol for women to take away from clinic for home self administration
since COVID now also legal to supply mifepristone for home self administration
analgaesia supplied
phone advice 24/7
who can have an early medical abortion at home
women <10wks gestation and prefer a home procedure and are healthy and have support
follow up for early at home abortion
low sensitivity pregnancy test at 2wks or scan sooner if minimal bleeding
