Contraception Part IV: Non-Hormonal Contraceptives Flashcards
Risk of Pregnancy
§ Approximately 5 – 6 days when unprotected intercourse can
result in pregnancy.
–Typically occurs in days 10 – 17 of a 28 day cycle.
§ Risk is 7 - 8 out of a 100 women (if unprotected intercourse in
2nd or 3rd week of cycle)
§ Breakdown of risk:
–~Unplanned pregnancy: 17-30% midcycle
•<1% during menses
Effectiveness of Non-hormonal Contraceptives
§ Copper IUDs are the most effective reversible contraception in
this category at 0.8% failure rate (will discuss this with LARC).
§ Surgical/Permanent contraception: women: tubal ligation (0.5%
failure rate); men: vasectomy (0.15%).
–Surgery for men considered to be more effective.
§ Barrier contraceptives: condoms, female condoms, diaphragms,
sponge, spermicides – typical use is 12 – 28%
§ Fertility awareness methods – typical use is 24%
§ Withdrawal – typical use is 22%
Barrier Methods: Male Condoms
§ Efficacy: 82-98%; with spermicide 95%
§ Types of condoms: latex, polyisoprene,
polyurethane, sheath of processed
lamb cecum (lambskin)
§ Prevention of STI (avoid lambskin condoms)
1– 6 % of people allergic to latex –
recommend polyurethane or polyisoprene
§ 1– 6 % of people allergic to latex – recommend polyurethane or
polyisoprene
§ Do not use oil-based vaginal creams (for example Monistat, Vagisil,
Premarin etc) or lubricants with latex condoms (for example
Vaseline, massage oil) – causes deterioration of latex
–Use water based lubricants (ie Astroglide, KY jelly)
§ Condom failure is often due to breakage or slippage
–Proper use reduces this risk
§ Be careful of the expiry date!
Barrier Methods: Female Condoms
§ Soft nitrile polymer sheath
containing two rings on each end
§ Single use, protects against
pregnancy effective against STI
§ Efficacy 79-95%
§ FC2 Female condom
§ Insert before intercourse, however can be inserted up to 8 hours before, after use twist the condom to seal semen and gently remove
§ Do not reuse the condom
§ Do NOT use together with male condom as slippage and device displacement can occur
§ Advantages: woman can place autonomously, safe to use with latex allergy, can be used with oil based creams/lubricants, male partner may find it more comfortable compared to male condoms
Barrier Methods: Diaphragm
cervical cap no longer avail
§ Reusable, soft silicone dome with flexible
spring
§ Inserted vaginally, fits over the cervix
§ Efficacy increases with spermicidal jelly
§ Can insert up to 2 hours before intercourse (more spontaneous)
§ Inserted prior to intercourse and left in
place at least 6 hrs after intercourse
§ Must be removed within 24 hours
§ Fitted diaphragms: Milex (Omniflex, Arcing)
–Recommended replace each year
§ No fitting required/one size: Caya diaphragm
–Can last up to 2 years
§ Adv: woman can place autonomously, safe
to use with latex allergy, can be used with oil
based creams/lubricants
Acid buffering gels that are used
Spermicide gels
Can be used around, put spemicide in dome and along the sides befroe insertion
Barrier Methods: Spermicides
§ 72-82% effective; 95% with condom
§ Available as cream, foam, gel, film
§ Earlier products with Nonoxynol 9 (N-9)
§ N-9 do not prevent HIV or STI’s, do not use
if increased risk of STI
can cause vaginal irritation and micro abrasions to happen, penetration of STI can happen
§ Other spermicidal agents found in products:
octoxynol, menfegol, benzalkonium
chloride
Barrier Methods: Spermicides
use
§ Foams (N-9): mix well by shaking the
container before use, insert the
required amount with applicator into
vagina up to 30 - 60 minutes before
intercourse.
§ VCF film (N-9): fold in half, insert into
vagina against the cervix, up to 15
minutes to 3 hours before intercourse
if no interncouse within 3 hours, need new one instered may not be effective
Barrier Methods: Sponge
more a spermicide than barrier
§ Contraceptive Sponge, Today sponge
§ Soft foam filled with spermicide
§ Inserted into vagina to cover the cervix
§ Insert before intercourse and leave in
place for 6 hours after intercourse.
§ Do not leave in longer than 30 hours.
Less effective in women who have given birth vaginally – due to changes that come from the vaginal delivery (ie cervix etc)
can be nserted up to 24 hours before
Fertility Awareness Methods*
§ Calendar Rhythm Method, Standard Days Method – both involve probable days of fertility based on menstrual cycle.
§ Symptothermal Method – Uses body basal temperature changes and cervical mucus changes to determine the fertile period.
§ Lactation Amenorrhea Method – must be less than 6 months postpartum, fully breastfeeding and amenorrheic. sometimes doesnt work
usuallt these methdos need a number of menstrual cycles to look at
hard for irregular periouds
do emergency cotnraception pills cause mini-abortions
Emergency contraceptions do not cause mini abortions
Have no effect on establish preganacy
They preven pregancy (primarily prevent ovuation)
Therefore do not cause abortion
Emergy contra is dngerous cuz it has high doses of hormones
Myth - one-time dosage regimn is very safe to use - main AE is nausea
Emergency contraception refers to all methods of contraception
that are used after intercourse and before implantation.
■ Types of emergency contraception:
▪ Hormonal (EC’s)
▪ Levonorgestrel
▪ Ulipristal
▪ Yuzpe method
▪ Post-coital insertion of copper IUD
Indications for EC
Unprotected or inadequately protected
intercourse
Failure to use contraceptive method
Condom breakage or leakage
Dislodgement of diaphragm or cervical cap
Missed CHC’s (see Table)
Ejaculation on the external genitalia
Mistimed fertility awareness
Sexual assault
Barriers to the Use of Emergency
Contraception
■ Lack of awareness and understanding of emergency
contraception (EC):
▪ Do not know about EC
▪ Some may think it is only “morning after”
▪ Moral beliefs of both patients and providers
▪ Fear of adverse effects
▪ Lack of understanding of how it works
Hormonal EC
■ Exact mechanism unclear but theoretically EC may:
▪ prevent/delay the release of an egg from the ovary –
primary mechanism, interferes with ovulation
▪ prevent fertilization – inhibit sperm binding
▪ inhibit the transport of the egg or sperm in the fallopian
tubes – prevent contractility
▪ prevent implantation of a fertilized egg by causing changes
in the lining. (NOT A MECHANISM, NOT ENOUGH TO CAUSE ONGOING CHANGE, THERE MUST BE ONGOING CHANGES TO AFFECT IT)
■ Earliest method was the “Yuzpe regimen”:
▪ One dose = 100 μg ethinyl estradiol and 1 mg norgestrol or 500 μg
levonogestrel
▪ 2 treatment doses 12 hours apart
EQUIV TO
Alesse 5 pills 100 µg EE 500 µg
Min-Ovral 4 pills 120 µg EE 600 μg
Triquilar 4 yellow 120 µg EE 500 µg
Levonorgestrel (LNG)
▪ Plan B®, generics (Back-Up Plan®, Contingency®)
■ Schedule III
■ Doses:
▪ a single dose of 1.5 mg levonorgestrel
two-tablet format (before 0.75mg) has been replaced with one-tablet forma
■ LNG-EC primary mechanism: interferes with ovulation by
affecting follicular development before LH surge.
■ Most effective if taken within 72 after unprotected
intercourse, but has been shown to be effective up to 120 hours (5 days).
■ The earlier the use the better the efficacy
■ LNG is more effective compared to Yuzpe
how many days is seprm viable?
How many day is ovum viable?
5 days for sperm, 24-48 hours for ovum
■ LNG prevents:
▪ 95% of pregnancies if taken within 24 hours
▪ 85% of pregnancies if within 25 – 48 hours
▪ 58% of pregnancies if within 49 – 72 hours
■ NOTE: newer data effectiveness for LNG-EC: reduces
pregnancy by 50%.
Cu IUD most effective, LNG EC better than Yuzpe EC
LNG Contraindications
Very few contraindications/drug interactions for LNG EC.
Contraindications:
■ Absolute:
▪ Known pregnancy
▪ Known hypersensitivity
▪ Product monograph: warns about repeat use in women with
breast or liver carcinoma. (contains progestin), it’s ok for one time use
■ Drug interactions:
▪ Rifampin (potent enzyme inducer) – may be clinically
significant (Some Europe guideliens recommend double dose)
will not affect pregnancy if there,
Side Effects – Hormonal EC
Side effects Yuzpe method LNG
spotting 30% 24%
nausea 50% 23%
cramps 21% 18%
fatigue 29% 17%
headache 20% 17%
breast tenderness 12% 11%
vomiting 19% 6%
Hormonal EC – Return of Menses
■ Most patients will have their menses within 3 weeks of taking
EC:
▪ usually around the time of their normal expected period (within 3 days
of the expected date)
■ If the patient does not have period within 3 - 4 weeks, should follow-up with physician.
Hormonal EC – Repeat Uses
as primary method of contraception
■ There are no known medical restrictions with repeat use of hormonal EC.
■ Repeat use of EC is less effective than other methods of contraception (if used as the only contraceptive method).
▪ Annual risk of pregnancy with LNG – 19%
▪ Annual risk of pregnancy with Yuzpe method – 38%
Transition to Hormonal Contraceptives
■ EC is a good opportunity to discuss/educate on ongoing
contraceptive needs.
■ If starting or continuing CHC then can start the day or or the
next day after taking EC. Backup contraception required for 7
days.
▪ Same recommendations for other hormonal contraceptives including
LNG-IUS, contraceptive implants etc.
Ulipristal
■ Ulipristal acetate, ella® - Schedule 1
■ Selective progesterone receptor modulator (progesterone
antagonist and partial progesterone agonist)
■ MOA: direct inhibitory effect on follicular rupture
■ Dose: 30 mg single tablet
■ Consistent efficacy over the 5 days
■ Effectiveness about 60-70%
■ Ulipristal EC may be more effective than LNG-EC
has direct effect
Possible reason: ulipristal can prevent ovulation even after LH surge has begun (LNG-EC only effective before LH surge)
