Contraception Flashcards
What are the two main contraceptive mechanisms?
1) Inhibiting the development and release of the egg
- OCP, Depo progesterone, patch, ring
2) Imposing mechanical, chemical or temporal barrier between the sperm and egg
- Condom, diaphragm, IUD, natural family planning
What is the difference between method failure rate and typical failure rate?
- Method Failure Rate: Failure rate of a contraceptive if used correctly 100% of the time
- Typical Failure Rate: Failure rate seen in typical use, accounting for occasional mistakes and non-compliance
True or false, hormonal contraceptives can decrease a womans risk of developing ovarian or uterine cancer?
- True
What is the mechanism of action of combined oral contraceptive preparations? (ie. what does the progesterone do, what does the estrogen do?)
1) Progesterone: supresses secretion of LH, and thus ovulation. Also causes thickening of cervical mucous to prevent sperm penetration, alters fallopian tube peristalsis, and inhibits sperm movement.
2) Estrogen: Suppresses secretion of FSH, which prevents the maturation of the follicle
What are “phasic” oral contraceptives?
- These pills vary the ratio of Progesterone:Estrogen during the course of the cycle
- Leads to slightly less hormone uses, but has slightly higher rate of breakthrough bleeding (spotting)
What is a “mini-pill”? How does it work?
A progestin only oral contraceptive pill
- Uses a lower dose, so the main mechanism is cervical mucous thickening as 40% of patients on this will continue to ovulate normally.
How would you counsel a patient starting the mini-pill?
- Must be taken at the same time every day!
- Start taking it on the first day of your cycle
- If more than 3hrs late taking pill, use back-up contraception for 48 hours
Break through bleeding occurs in 10-30% of patients taking low dose oral contraceptives during the first how many months? - councelling point
- 3 months. Typically will resolve spontaneously afterwards
What are some of the minor side effects of estrogen?
- Bloating
- Weight gain
- Breast tenderness
- Nausea
- Fatigue
- Headache
What are the absolute contraindications to the use of combined OCP?
- Thromboplebitis or Thromboembolic disease
- Undiagnosed abnormal vaginal bleeding
- Cerebral vascular disease
- Know or suspected pregnancy
- Coronary occlusion
- Smoker > 35 years old
- Impaired liver function
- Congenital hyperlipidemia
- Estrogen dependent tumour (Br or Uterus)
- Hepatic neoplasm
- Migraines with neurological symptoms (excluding aura)
- Uncontrolled hypertension
Which drugs can reduce the efficacy of oral contraceptive pills?
- Barbituates
- Benzodiazapines
- phenytoin
- carbamazapine
- rifampin
- sulfonamides
The contraceptive patch is less effective in women weighting over what amount?
- 90kg or 198lbs
What is one of the primary concerns associated with Depo-Provera (DMPA) injections?
- Decreased bone density (due to changes in bone metabolism associated with decreased estrogen - like in menopause)
- Appears to be reversible following discontinuation
How long after discontinuing Depo-provera does it take to resume normal menses?
- 50% will resume within 6 months
- 25% do not resume normal menses for over a year
What are the barrier methods of contraception?
- Condom
- Diaphragm
- Cervical cap
- Sponge
What is the active ingredient in spermacide?
- N-9 (Nonoxynol-9)
How does a copper IUD work?
- Prevent eggs from being fertilized or from attaching to the wall of the uterus
How does a progesterone containing IUD work?
- Prevents the egg from being fertilized
- Thickens the cervical mucous and creates an unfavourable uterine environment
What does a progesterone containing IUD do to the severity of dysmenorrhea and the volume of menstrual blood loss?
- Decreases severity of dysmenorrhea
- 50% reduction in menstrual blood loss
- Make a key treatment option in endometriosis and adenomyosis
How long can the copper IUD stay in place for while remaining effective?
- 10 years
How long can the progesterone IUD stay in place for while remaining effective?
- 5 years
What is the expulsion rate for IUD’s? When is this risk the highest?
- 1%-5%
- The risk is highest in the first few months of use
Does having an IUD increase your change of having an ectopic pregnacy?
- NO!
- No increase in risk of ectopic pregnancy overall, however because very low chance of intrauterine pregnancy, the ratio of ectopic to normal pregnancies increases
What are contraindications for the IUD?
- Pregnancy
- Pelvic inflammatory disease within the past 3 months
- STI (current)
- Purulent cervicitis
- Undiagnosed AUB
- Malignancy to genital tract
- Uterine anomalies blocking insertion
- Allergy, or copper IUD in wilson disease
What is the calendar method?
- based on calculation of a womans fertile period.
- for a regular 28 day cycle the fertile period would be days 10 through 17
What is the yuzpe method?
- A form of emergency post-coital contraception performed by:
- Taking 2 tablets of combined OCP within 72 hours of unprotected intercourse, followed by another 2 tablets in 12 hours
What is plan B?
A progestin only emergency contraception formulation
- Take two tablets at once or 12 hours apart.
- Greater effectiveness with less side effects than Yupze method
How does plan B work?
- Temporarily stops the release of an egg from the ovary (by negative feedback to hypothalamus)
- Prevents fertilization (thickening cervical mucous)
- Prevents a fertilized egg from attaching to the uterus (alteration to the endometrium)
