Contraception Flashcards
what % of pregnancies are unplanned?
40-60%
~50% of unplanned pregnancies end in abortion
what is GnRH and what does it do?
gonadotropin-releasing hormone stimulates pituitary to release FSH and LH from hypothalamus
what is FSH and what does it do?
follicle stimulating hormone stimulates maturation of follicles in ovaries
what does estrogen do?
stimulates thickening of the endometrium (uterine lining)
suppresses FSH (negative feedback)
signals LH
what is LH and what does it do?
luteinizing hormone triggers ovulation
what does progesterone do?
makes the endometrium favorable for implantation
signals the hypothalamus and pituitary to stop FSH and LH production (negative feedback)
where is progesterone produced?
the corpus luteum
what is the follicular phase?
days 1-7
day 1: first day of period
days 1-4: increase FSH (follicle grows)
days 5-7: one follicle becomes dominant, starts producing estrogen, stops menstrual flow, stimulates thickening of endometrial lining
when does ovulation occur?
~28-32 hours after the LH surge
typically around day 14 or a regular cycle
what is the luteal phase?
*14 days long
released ovum travels through fallopian tubes to the uterus
“left over” follicle becomes corpus luteum
- produces estrogen and progesterone
- provides negative feedback to stop FSH and LH production
- maintains endometrial lining
what happens if there is no implantation?
corpus luteum deteriorates and stops producing progesterone
what happens if implantation occurs?
corpus luteum continues to produce progesterone.. but that function is taken over by the placenta
when does the luteal phase switch to follicular phase?
as progesterone levels decrease and endometrial lining is shed (menstruation)
what stimulates the release of GnRH?
low levels of progesterone and estrogen
what is the difference between efficacy and effectiveness?
efficacy = how well something works in an ideal situation
effectiveness = how it happens in real life (drops about 10% usually)
what are the different contraception methods?
hormonal
barrier
permanent
natural family planning
what are the components of hormonal contraceptives?
estrogen - ethinyl estradiol (EE)
progestins - numerous options
what is the MOA of hormonal contraceptives?
estrogen and progestin provide negative feedback which inhibits ovulation
what is estrogens role in HC?
suppresses release of FSH
what is progestins role in HC?
suppresses release of LH and FSH
thickens cervical mucus
changes endometrial lining (the difference from progesterone)
what are the administration forms of HC?
oral(the pill)
injectable
transdermal
intravaginal
intrauterine
implantable
what are the categories of HC?
combined
progestin-only
long-acting reversible contraception (LARC)
what are the combined HC?
pill
patch
ring
what are the progestin-only HC?
pill
injection
what are the LARC HC?
IUD/IUS
implant
what are the 3 phasic formulations?
monophasic
biphasic
triphasic
what is monophasic?
fixed levels of EE and progestin
what is biphasic?
fixed EE levels
increase progestin in 2nd phase
what is triphasic?
fixed or variable EE levels
increase progestin in all 3 phases
what is extended dosing?
> 1 cycle of active pills the HFI
what is continuous dosing?
uninterrupted, no HFI
might be better to use monophasic (same level of hormone)
why do extended or continuous dosing?
less risk of ovulation
highest risk of ovulation when you miss the first pill in a pack
less “periods” - less period pain
when should the combined OC pill be started?
most effective if started on day 1 of period
can start on the first sunday after period starts (to avoid weekend period)
but can also start any day of the cycle
what do you need to do if not starting the combined OC pill on day 1?
use backup birth control for first 7 days
what is the efficacy of combined OC pill?
perfect use: <0.3% failure rate
typical use: 3-8% failure rate
adverse effects of combined OC common in first 3 months
breakthrough bleeding
breast tenderness
nausea
adverse effects of combined OC
weight gain
headache or migraine
mood changes
acne - can initially worsen but improve with long term use
benefits of combined OC
simple and effective birth control
improve menstrual symptoms and regularity
decreases incidence of endometriosis, endometrial cancers, ovarian cancers, ovarian cysts, osteoporosis, acne and hirsutism
risks of combined OC
contraceptive failure
venous thromboembolism (VTE)
MI and stroke (arterial thrombosis)
breast cancer
cervical cancer
what are the early danger signs of combined OC?
A - abdominal pain (severe)
C - chest pain (severe) and SOB
H - headaches (severe)
E - eye problems (blurring, flashing, vision loss)
S - severe leg pain (calf or thigh)
what drug interactions do combined OC have?
- drugs that reduce enterohepatic circulation of oral contraceptives
CYP450 3A4 inducers(anticonvulsants, anti-infectives, st johns wort) - drugs that induce the metabolism or oral contraceptives
Lamotrigine - drugs that have their metabolism altered by oral contraceptives
when are combined OC contraindicated?
thromboembolic disease
hypertension (>160/100)
ischemic heart disease / stroke
known or suspected breast cancer
migraine with aura
severe / active liver disease
post-partum - wait at least 3-6 weeks
smokers over 35 years old
what is in the transdermal patch (Evra)?
0.6mg ethinyl estradiol + 6.0mg norelgestromin
what is the efficacy of the transdermal patch?
perfect use: failure rate = 0.3-0.7%
typical use: failure rate = 8%
where should the patch be applied?
upper arm
butt
lower abdomen
upper torso
adverse effects of the patch
similar to OC
local skin irritation
can have increased spotting in first 2 cycles
less effective and increase risk of clots if weighing >90kg
drug interactions of the patch
similar to combined OC
what is the intravaginal contraceptive and what is in it?
flexible, non-latex vaginal ring(Nuvaring)
- EE 15mcg + 120mcg etonogestrel released daily
what is the efficacy of the ring?
perfect use: failure rate = 0.3-0.8%
typical use: failure rate = 8%
administration for nuvaring
insert into vagina
leave in for 3 weeks, remove for 1 week (HFI)
how long can you remove the ring for?
less then 3 hours
adverse effects of the ring
similar to combined OC
vaginitis
foreign body sensation / discomfort
problems during sex
what are the drug interaction for the ring?
similar to combined OC
how does the nuvaring need to be stored?
store in fridge at pharmacy
stable at room temp for 4 months
how long can you use the ring for before replacing it?
until expiry
and there is one on in the states that you can use for 1 year
what is in the progestin-only pill (“mini-pill”)?
norethindrone or drospirenone
what is movisse and jencycla and how is it taken?
norethindrone 35mcg daily (no HFI)
what is slynd and how is it taken?
drospirenone 4mg QD x 24 days then 4 placebo pills
what is the MOA of norethindrone?
alters cervical mucous and endometrium
can alter ovulation in 50-60% of women (suppresses FSH/LH)
what is the MOA of drospirenone?
primarily suppresses ovulation
when is the progestin-only pill indicated?
if estrogen is contraindicated
- history/risk of blood clot
- smoker >35
- obese
- migraine
breastfeeding - won’t decrease milk supply
what is the efficacy of the progestin-only pill?
perfect use: failure rate = 0.5%
typical use: failure rate = 5-10%
administration for norethindrone
start on day 1 and take QD continuously
back up method required for 2 days
MUST take at same time every day (within 3 hours)
administration for drospirenone
start on day 1 take QD continuously (24/4)
back up method required for 7 days
adverse effects of progestin-only pill
irregular bleeding (more so in first months)
headache
bloating
acne
breast tenderness
when is the progestin-only pill contraindicated?
liver disease
breast cancer
drug interactions similar to combined OC
what is in the progestin injection?
150mg medroxyprogesterone acetate
what is the MOA of the injection?
prevents ovulation by suppressing LH/FSH surge
increase viscosity of cervical mucous
potentially alters the endometrial lining to make it inhospitable to implantation
efficacy of the injection
perfect use: failure rate = 0.3%
typical use: failure rate = 3-7%
- due to delayed or missed dose
administration for injection
given IM q 12 weeks
no backup method required if injected on day 1-5
if injected after day 5 use backup method for 3-4 weeks
what do do for missed dose of injection
if given >14 weeks do pregnancy test, EC prn, backup method for contraception
adverse effects of injection
unpredictable bleeding in first months
acne, headaches, nausea, decreased libido, breast tenderness
weight gain (<2kg)
may decrease bone mineral density
delayed return to fertility (average 9 months)
benefits of injection
no estrogen
few drug interactions
amenorrhea (~60% at 12 months)
less adherence issues
contraindications of injection
breast cancer
uncontrolled hypertension
stroke / IHD
liver disease
what was the first IUD?
the dalkon shield in 1950
MOA of copper IUD
copper is released and produces an inflammatory reaction that is toxic to sperm, makes sperm transport difficult and possibly prevents implantation
when does the copper IUD need to be replaced?
every 3-10 years (product dependent)
efficacy of copper IUD
failure rate = 0.6%
what is in a hormonal IUD (IUS)?
levonorgestrel
how much drug does the mirena deliver?
20mcg/day initially.. to 10mcg/day
how much drug does the kyleena deliver?
17.5mcg/day initially.. to 9mcg/day
what is the MOA of a hormonal IUD?
- thickens cervical mucous to prevent sperm transport and permeability
- alters endometrial lining to prevent implantation
- can suppress ovulation in some individuals (some eventually develop amenorrhea)
effectiveness of hormonal IUD
failure rate = 0.2%
expulsion can occur (~6%/5 years)
when should a hormonal IUD be inserted?
best if inserted on last few days of period (within first 7 days of cycle)
adverse effects of IUDs
- increased bleeding and cramping in first few months, but usually subsides
- very rare for preforations
- pelvic inflammatory disease (~1%)
contraindications of IUDs
pregnancy
breast, cervical, endometrial cancer
STI or pelvic infection within 3 months
what is the implantable contraception?
progestin-only nexplanon
what is in the nexplanon?
etonogestrel 68mg - up to 70mcg delivered daily
how long does nexplanon last?
up to 3 years
what is the MOA of nexplanon?
inhibits ovulation
changes cervical mucous
effectiveness of nexplanon
> 99% effective
when should nexplanon be inserted?
day 1-5 of cycle
- use backup for 7 days if after day 5
adverse effects of nexplanon
bleeding irregularities
headache
weight increase
breast pain
may migrate in some cases
contraindications of nexplanon
pregnancy
breast cancer
what are the barrier methods?
condoms
diaphragms
sponges
cervical cap
spermicides
efficacy of external condoms
perfect use: failure rate = 3%
typical use: failure rate = 14%
efficacy of internal condoms
perfect use: failure rate = 5%
typical use: failure rate = 20%
what is a diaphragm?
reusable, dome-shaped cap that covers the cervix
requires initial fitting by clinician
what is a sponge?
impregnated with spermicidal agents
what is a cervical cap?
smaller than a diaphragm - fits over cervix
requires initial fitting by a clinician
what is spermicide?
nonoxynol-9
surfactant that destroys the cell wall of sperm (kills and immobilizes sperm)
used with sponges, diaphragms and cervical caps
what are the forms of permanent contraception?
tubal ligation - occlusion of the fallopian tubes
vasectomy - occlusion of the vas deferens
efficacy of tubal ligation
failure rate:
- 0.5% after 1 year
- 1.8% after 10 years
efficacy of vasectomy
failure rate:
- 0.2% after 1 year
- 2.2% after 10 years
what is natural family planning?
no contraceptive devices or chemicals
revolves around timing of ovulation
failure rates of natural family planning
fertility awareness - up to 24%
coitus interruptus - up to 22%
abstinence - 0%
natural family planning with basal body temp
take temp first thing in the morning (at the same time each day)
increase of at least 0.2C above baseline temp indicates ovulation has occurred
after 3 consecutive days of increased temp, fertile period considered over
doesn’t predict beginning of fertile period
billings method for natural family planning
identify fertile period by recognizing change in consistency and volume of cervical mucous
- changes around ovulation
- becomes clearer, slippery and more elastic as ovulation nears
- after ovulation, mucous becomes more viscous and less volume
calendar method for natural family planning
chart menstrual cycle over 6-12 cycles
determine fertile period
- subtract 21 from length of shortest cycle (fertility begins)
- subtract 10 from length of longest cycle (fertility ends)
*doesn’t account for factors that influence timing of ovulation
lactational amenorrhea method
physiological infertility from breastfeeding caused by hormonal suppression of ovulation
98% effective if:
- exclusively breastfeeding
- baby <6months old
- period hasn’t resumed
what is EC?
any form of birth control used after intercourse but before implantation
- last chance to prevent pregnancy
what schedule is plan B?
3
define fertilization
process of combining the sperm with the ovum
define pregnancy
begins with implantation of fertilized ovum (implantation occurs ~6-14 days after fertilization)
define contraception
prevention of pregnancy
define medical termination
disruption of implanted pregnancy and induction of uterine contractions
when is EC indicated?
patient is of reproductive age
patient does not want to get pregnant
patient has had unprotected sex within the past 120 hours (5 days)
how long is plan b (LNG) approved for after unprotected sex?
up to 72 hours (3 days)
how long is Ella(UPA) approved for after unprotected sex?
up to 120 hours
how long is the copper IUD approved for after unprotected sex?
up to 7 days (maybe longer)
when is the risk of pregnancy the greatest?
5 days before ovulation to 1 day after because sperm survive up to 5 days and egg survives 12-24 hours
what are the EC options?
oral - ella, plan b, combination OCP
device - copper IUD
what is the drug in ella?
ulipristal acetate 30mg (1 tab)
what is the drug in plan b?
levonorgestrel 1.5mg
how does the copper IUD work for EC?
the MOA induces sterile inflammatory reaction in uterus.
by products of inflammation and copper are toxic to sperm and egg
also may prevent implantation
what is the MOA of ella?
prevents or delays ovulation
must be given before or during the peak of the LH surge
what is the MOA of plan b?
delays ovulation
may inhibit sperm/ova travel
must be given before the peak if the LH surge
which combined OC can be used for EC?
alesse - 5 pills/dose
triquilar - 4 pills/dose
min-ovral - 4 pills/dose
adverse effects of EC
nausea
vomiting
cramps
fatigue
headache
breast tenderness
how long after taking UPA(Ella) can you restart HC?
5 days
what EC is preferred for use due to missed HC?
LNG (plan b)
which EC is preferred in people with BMI 25-30?
UPA(ella)
copper IUD if BMI >30
are there any contraindications to EC?
pregnancy or allergy to something in the EC
what is in mifegymiso?
mifepristone 200mg - progesterone receptor modulator
misoprostol 800mg (4 x 200mg)
what is mifegymiso?
terminates pregnancy of up to 63 days
