Contraception Flashcards
what are the 5 main hormones involved in the menstrual cycle?
gonadotropin release hormone (GnRH)
follicle stimulating hormone (FSH)
estrogen (mainly estradiol)
luteinizing hormone (LH)
progesterone
what is the role of gonadotropin release hormone (GnRH) in the menstrual cycle?
stimulates pituitary to release FSH and LH
what is the role of follicle stimulating hormone (FSH) in the menstrual cycle?
stimulates maturation of follicles in ovaries
what is the role of estrogen in the menstrual cycle?
stimulates thickening of the endometrium
suppresses FSH (negative feedback)
signals LH
what is the role of luteinizing hormone (LH) in the menstrual cycle)?
triggers ovulation
what is the role of progesterone in the menstrual cycle?
makes the endometrium favourable for implantation
signals the hypothalamus and pituitary to stop FSH and LH production (negative feedback)
where is progesterone produced?
produced by the corpus luteum: mass of cells resulting from ruptured follicle when the ovum is released
how long is the average menstrual cycle?
28 days
what day of the menstrual cycle is the first day of the period?
day 1
what are the two phases of the menstrual cycle?
follicular phase and luteal phase
when is the follicular phase?
starts on day 1
is typically around 14 days but can vary
what occurs during the follicular phase?
day 1: first day of period
day 3-4: increase FSH (follicle grows/develops)
day 5-7: one follicle becomes dominant and starts producing estradiol
stops menstrual flow
stimulates thickening of endometrial lining
increased production of thin, watery, cervical discharge
consistently high estrogen levels stimulate the pituitary to release a mid cycle surge of LH
LH = follicle maturation and triggers ovulation
when does ovulation occur?
about 28-32 hours after the LH surge (in the follicular phase)
when is the luteal phase
occurs after ovulation
always 14 days
what occurs during the luteal phase?
released ovum travels through fallopian tubes to the uterus
“left over” follicle becomes corpus lumen
produces androgens, estrogens, and progesterone
progesterone provides negative feedback to stop FSH and LH
maintains the endometrial lining
what occurs to the corpus luteum if no implantation occurs?
corpus luteum deteriorates and stops producing progesterone
what occurs to the corpus luteum if implantation occurs?
corpus luteum continues to produce progesterone but that function is ultimately taken over by the placenta
what happens after the luteal phase if no implantation occurs?
progesterone levels decrease –> follicular phase
endometrial lining is shed (menses)
low progesterone and estrogen levels stimulate the release of GnRH and cycle starts all over again
what are the 2 forms of estrogen available in contraception?
ethinyl estradiol (EE): synthetic form of estradiol, most common
estetrol: plant source
what are progestins?
synthetic hormones that activate progesterone receptors
which progestins are anti-androgenic?
cyproterone acetate
drosperinone
what is the MOA of combination hormonal contraception?
estrogen and progestin provide negative feedback which inhibits ovulation
estrogen: suppresses release of FSH
progestin: suppresses release of LH and FSH; thickens cervical mucous (impedes sperm transport); changes endometrial lining (not hospitable to implantation)
what is monophasic dosing of combination OC?
fixed levels of EE and progestin
what is biphasic dosing of combination OC?
fixed EE levels with increased progestin in 2nd phase
what is triphasic dosing of combination OC?
fixed or variable EE levels with increasing progestin in all 3 phases to mimic normal cycle
what is extended dosing of combination OC?
planned HFI
>1 “cycle” of active pills then HFI
ex: 84 days of active drug + 7 days EE or HFI
what is continuous dosing of combination OC?
uninterrupted, no HFI
what products can you use for continuous dosing of combination OC?
any product (<50 mcg EE)
oral, transdermal, vaginal
even multiphasic products
T or F
extended/continuous regimens are more forgiving for missed doses?
True
most missed doses occur at the start of a new pack so continuous/extended dosing avoids this issue
when should you start combination OC?
most effective if started on day 1 but can be started at any time
how long should you use back up contraception for after starting combination OC?
if started taking on day 1 = do not need to use back up
if started any other day = use back up for 7 days
what do you do if you miss a pill during week 1 of your cycle?
take 1 pill ASAP and continue as usual to the end of the cycle
consider EC if unprotected sex in last 5 days
use back up protection for 7 days
what is the efficacy of combination OC?
perfect use = <0.3% failure rate
typical use = 3-8% failure rates
what do you do if you miss a pill during week 2 or 3 of your cycle?
take 1 pill ASAP and continue as usual to the end of cycle
start new cycle of CHC without HFI (discard placebo pills if any)
consider EC if 3+ pills missed and unprotected sex in last 5 days
use backup for 7 days if 3+ days missed
what do you do if you miss a pill at the start of a new pack?
resume cycle ASAP
consider EC
use back up contraception for 7 days if EC is indicated
which side effects are common within the first 3 months of starting combination OC?
breakthrough bleeding
breast tenderness
nausea
what are most side effects of combination OC caused by?
estrogen
what do you do if breakthrough bleeding lasts for more than 6 months on combination OC?
check adherence
look for other causes (STI)
change to pill with increased estrogen/progestin (depending on when BTB occurs)
in first phase = increase estrogen
in second phase = may be due to progestin
what are the side effects of combination OC?
weight gain
headache or migraine – can either increase or decrease with use
mood changes – depression
acne – usually do to progestin – some help
how can some combination birth controls help reduce acne?
lowers amount of endogenous androgens produced or (bio)available (androgens stimulate sebum production = acne)
what are the benefits of combination OC?
simple and effective
improves menstrual symptoms and regularity: decreases dysmenorrhea, ovulation pain, PMS symptoms
decreases incidence of: endometriosis, endometrial cancers, ovarian cancer, ovarian cysts, osteoporosis (increases bone density), acne and hirsutism
what are some risks involved with combination OC?
contraception failure
venous thromboembolism (VTE)
MI and stroke (arterial thrombosis)
breast cancer
cervical cancer
what increases the risk of VTE and arterial thrombosis on combination OC?
increased age
higher estrogen dose
smoker
HTN
T or F
common antibiotics may reduce the efficacy of birth control
False
not really a problem (with the exception of rifampin)
what are the 3 types of potential DI with OCP?
drugs that reduce enterohepatic circulation (Abx)
drugs that induce metabolism
metabolism altered by oral contraceptives
which drugs interact with OCP by inducing metabolism?
anticonvulsants (carbamazepine, phenytoin)
anti-infectives (rifampin)
herbals (St. Johns wart)
how to deal with DIs of OCP due to induction of metabolism?
use product with higher estrogen levels (>30 mcg EE)
use extended dosing (skip HFI)
use alternative to interacting drug or other method of birth control (do not change anti-convulsants)
which drugs metabolism is altered by OCPs?
lamotrigine
significantly lowers levels - induction of lamotrigine glucuronidation
what are CI of combination OC?
thromboembolic disease (current or past VTE)
ischemic heart disease/stroke
migraine with aura = increase in clots
smokers (>15 cigs/day) over 35
HTN (>160/100)
known or suspected breast cancer
severe/acute liver disease
post partum
how long after having a baby do you have to wait until you can take combination OC and why?
3-6 weeks post partum
increase risk of VTE
what amounts of hormones are in the transdermal patch (Evra) and how much is released each day?
0.6 mg EE + 6.0 mg norelgestromin?
average daily release of 35 mcg EE and 200 mcg norelgestromin
what is the efficacy of Evra?
perfect use = failure rate of 0.3-0.7%
typical use = failure rate of 8%
when should you start using Evra?
most effective if started on day 1 of cycle but can start at any point
for how long should you be using back up contraception after starting Evra?
if started on day 1 = no back up needed
if started any other day = back up for 7 days
how do you use Evra?
1 patch applied weekly = 3 weeks then no patch for 1 week (HFI)
applied to upper arm, buttock, lower abdomen, upper torso
what are the adverse effects of Evra?
similar to combination OC
local skin irritation
can have increased spotting in first 2 cycles
less effective and increase risk of clots if weigh >90 kg (200 lbs)
what are DI with Evra?
similar to combination OC
rifampin, lamotrigine, anticonvulsants, etc.
how much hormones are released daily with Nuvaring?
15 mcg EE+ 120 mcg etonogestrel released daily
what is the efficacy of the Nuvaring?
perfect use = failure rate of 0.3-0.8%
typical use = failure rate of 8%
how do you use the Nuvaring?
insert (anywhere in the vagina), leave in for 3 weeks then remove for one week (HFI)
how long should you use back up contraception for after starting the Nuvaring?
if started on day 1 = no back up needed
inserted on any other day = use backup for 7 days
how long can you leave Nuvaring out for during cycle?
less than 3 hours
what are some adverse effects of Nuvaring?
similar to combination OC
vaginitis
foreign body sensation/discomfort
problems during sex (can remove during sex then reinsert)
how do you store nuvaring?
store in fridge in pharmacy
stable at room temp for 4 months
what are the norethindrone only pills and how much hormones are in them?
Micronor (d/c), Movisse, Jencylon
35 mcg daily
what is the MOA of norethindrone?
affect cervical mucus and endometrium
in 50-60% of women can alter ovulation (suppresses FSH/LH) and cause amenorrhea
how do you take norethindrone?
take 1 pill every day - no HFI
how long after starting norethindrone should you use back up contraception for?
back required for 2 days (regardless of when started)
T or F
as long as you take norethindrone within 24 hours, it is still okay
False
norethindrone must be taken within 3 hours of the same time everyday
the effect on the cervical mucus only lasts around 24 hours
what do you do if you miss a dose of norethindrone (more than 3 hours)?
take missed pill ASAP then use back up for 2 days
what pills contain drospirenone only and how much hormone is in them?
Slynd
4 mg
how do you take drospirenone?
take 1 pill OD for 24 days then 4 days HFI
what is the MOA of drospirenone?
primarily suppresses ovulation
how long should you use back up protection for after starting drospirenone?
7 days regardless of what day started on
what are some indications for progestin only birth control?
estrogen CI: Hx/risk of blood clots, smoker >35, obese, migraine
breast feeding: wont decrease milk supply
what is the efficacy of progestin only OC?
perfect use = failure rate of 0.5%
typical use = failure rate of 5-10%
what are some adverse effects of progestin only pill?
irregular bleeding (more so in 1st month)
headache
bloating (wt gain)
acne
breast tenderness
potential to increase potassium
what are some CI of progestin only OC?
similar to combination OC: liver disease, breast cancer
how much hormone is in depo-provera?
150 mg of medroxyprogesterone acetate
what is the MOA of depo?
prevents ovulation by suppressing LH/FSH surge
increase viscosity of cervical mucous
potentially alters endometrial lining to make it inhospitable to implantation
what is the efficacy of depo?
perfect use = failure rate of 0.3%
typical use = failure rate of 3-7%
how is depo administered?
given IM every 12 weeks
how long does depo last for?
max effectiveness is 13 weeks (allows for a 1 week grace period)
how long to use back up contraception for after starting depo?
if injected on day 1-5: no back up needed
if injected after day 5: back up for 3-4 weeks (according to monograph; 1 week is sufficient)
what do you do if you miss a dose of depo?
if given after 13 weeks, do pregnancy test, EC prn and use back up
what are some adverse effects of depo?
unpredictable bleeding in first months (gets better with time)
hormonal associations: acne, headaches, nausea, decreased libido, breast tenderness
weight gain (<2 kg)
may decrease bone mineral density: especially in first 2 years
delay return to fertility of around 9 months
in what situation should you not consider depo?
if wanting to get pregnant in the next 2 years
what are some benefits of depo?
no estrogen
few DIs
amenorrhea (around 60% at 12 months)
less adherence issues
what are CIs of depo?
breast cancer
uncontrolled HTN/stroke/IHD
liver disease
what was the first intrauterine contraception and how did it work?
Dalkon shield
prongs keep it in place making it painful to insert
how often do you need to replace the copper IUD?
every 3-10 years (product dependent)
what is the difference between an intrauterine device (IUD) vs intrauterine system (IUS)?
an IUS contains hormones while an IUD does not
what is the MOA of the copper IUD?
copper is released and produces an inflammatory reaction that is toxic to sperm, making sperm transport difficult and possibly prevents implantation
what is the efficacy of the copper IUD?
failure rate = 0.6%
what hormone is in an IUS?
levonorgestrel
how often do you need to replace Mirena IUS?
every 5 years
how often do you need to replace Kyleena IUS?
every 5 years
how much hormones does Mirena deliver?
20 mch/d initially to 10 mcg/day
how much hormones does Kyleena deliver?
17.5 mcg/d initially to 9 mcg/d
what is the MOA of IUSs?
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)
what is the effectiveness of IUSs?
failure rate = 0.2%
what is the expulsion rate of IUSs?
about 6% in 5 years
when is it best to insert an IUS?
best inserted on fast few days of period (within the first 7 days of cycle)
what are some adverse effects of IUSs?
increased bleeding and cramping in first few months, but usually subsides
very rare for perforations
pelvic inflammatory disease
what are the CI to IUSs?
pregnancy
breast, cervical, endometrial cancer
STI or pelvic infection within 3 months
what hormone is in Nexplanon?
etonogestrel 68mg
up to 70 mcg delivered daily
how long does Nexplanon last?
3 years
what is the MOA of Nexplanon?
inhibits ovulation, changes cervical mucous
what is the effectiveness of Nexplanon?
> 99% effective
how long to use back up contraception for after insertion of Nexplanon?
if inserted after day 5 = use back up for 7 days
where is Nexplanon inserted?
directly under the skin of the inner side of non-dominant upper arm
what are some adverse effects of Nexplanon?
bleeding irregularities
headache
weight gain
breast tenderness
what are the CI of Nexplanon?
pregnancy
breast cancer
what are barrier methods of birth control?
condoms (external and internal)
diaphragms
sponges
cervical caps
spermicides
which kind of condom does not protect against STIs?
lambskin
what is the efficacy of condoms
external condoms:
perfect use: failure rate = 3%
typical use: failure rate = 14%
internal condoms
perfect use: failure rate = 5%
typical use: failure rate = 20%
what is a diaphragm?
reusable dome shaped cap that covers the cervix
what is a cervical cap?
smaller than a diaphragm - fits over the cervix
which barrier methods require fitting by doctor?
diaphragms and cervical caps
what is the MOA of spermicides?
nonoxynol-9: surfactant that destroys the cell wall of sperm (kills or inhibits)
what are the permanent forms of birth control?
tubal ligation: occlusion of the fallopian tubes
vasectomy: occlusion of the vas deferens
what is the failure rate of tubal ligation?
0.5% after 1 year
1.8% after 10 years
what is the failure rate of vasectomy?
0.2% after 1 year
2.2% after 10 years
what are the fertility awareness methods of contraception?
basal body temperature
billings method
calendar methods
lactational amenorrhea method
how does basal body temperature method of contraception work?
take temperature 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
doesnt predict beginning of fertile period therefore limit to only have sex after 3 consecutive days
what is the billings method of contraception?
identify fertile period by recognizing change in consistency and volume of cervical mucous
changes around time of ovulation
cervical mucous becomes clearer, slippery and more elastic as ovulation nears
after ovulation, mucous becomes more viscous and less volume
what is the calendar method of contraception?
chart menstrual cycle over 6-12 cycles
determine fertile period:
subtract 21 from length of shortest cycle (fertility begins)
subtract 10 from length of longer cycle (fertility ends)
doesnt account for factors that influence timing of ovulation (stress, illness)
what is the lactational amenorrhea method of contraception?
physiological infertility from breastfeeding caused by hormonal suppression of ovulation
98% effective if:
exclusively breastfeeding
baby <6 months
period hasnt resumed
what is the failure rate of coitus interruptus?
up to 22%
what is the definition of emergency contraception?
any form of birth control used after intercourse but before implantation
what are indications for EC?
pt is of reproductive age
pt does not want to get pregnant
pt has had unprotected sex within the last 5 days
how long is LNG effective for?
approve for up to 72 hours but some efficacy for up to 120 hours
how long is UPA effective for?
approved for up to 120 hours
how long is the copper IUD effective for for EC?
up to 7 days (and maybe even longer)
when is risk for pregnancy greatest?
5 days before ovulation to 1 day after
how long can sperm and egg survive?
sperm can survive for 5 days
egg can last for 12-24 hours
what is the most effective form of EC?
copper IUD
T or F
hormonal IUD can also be used for EC
not officially indicated by just as effective as copper IUD
what hormone is in plan B?
levonorgestrel (LNG) 1.5 mg
what hormone is in Ella?
ulipristal acetate (UPA) 30 mg
what is the MOA of UPA?
prevents or delays ovulation (blocks progesterone)
when must UPA be given?
must be given before or during the peak of the LH surge
what is the MOA of LNG?
delays ovulation
may inhibit sperm/ova travel
when must LNG be given?
must be given before the peak of the LH surge
T or F
both UPA and LNG have weening efficacy the later it is taken
False
LNG decreases in efficacy if used 72-120 hours after while UPA sees no difference in efficacy when taken 120 hours after
what is Yuzpe method of EC?
large doses of combine OC pills
how much EE and levonorgestrel must be taken for Yuzpe to work?
≥ 100 mcg EE and ≥ 500 mcg levonorgestrel
what are some side effects of EC?
nausea
vomiting
cramps
fatigue
headache
breast tenderness
which EC effects breast milk?
UPA
discard milk for one week after dose
Which EC is preferred if missed hormonal contraception is the reason for dose?
LNG
progestin may block UPA from working
When can you start taking OCP after taking UPA and LNG?
LNG: immediately
UPA: 5 days
which EC is recommended if BMI is over 25? over 30?
over 25 = UPA
over 30 = copper IUD
T or F
LNG and UPA are effective if unprotected sex occurs after EC dose?
False
What are CI of oral EC and IUD EC?
oral: pregnancy or allergy
IUD: pregnancy, unexplained vaginal/uterine bleeding, copper allergy, active pelvic infection
What medications are in Mifegymiso?
Mifepristone and Misoprostol
what is the MOA of misoprostol?
progesterone receptor modulator – termination of pregnancy
How long after fertilization is Mifegymiso effective for?
63 days
How is Mifegymiso taken?
Mifepristone taken orally
Misoprostol taken 24-48 hours later by buccal route (for 30 mins then swallow fragments with water)
What should you determine before recommending/prescribing EC?
date of last menstrual period
time since unprotected sex
did an additional unprotected sexual encounter occur since LMP?
that the individual wants EC
what should you determine before prescribing hormonal contraception?
at least 12 years old
medical history: risk factors and CI
medication history
do they want to become pregnant in the next year?
How long after taking oral EC should you retake the dose if vomitted?
LNG: 2 hours
UPA: 3 hours
How long after taking EC should patient expect to have a period?
about 21 days
