Contraception Flashcards
(35 cards)
What is the likelihood of getting pregnant within the first year of intercourse, with no contraception?
85%
What are the 6 broad categories of contraceptive methods?
- Physiological
- Barrier methods
- Hormonal - piils vs injection vs implanon
- IUD
- Surgical - tubal ligation, vasectomy
- Emergency contraception
How is ovulation detected best?
Basal body temperature rise
How does lactational amenorrhoea work as a contraceptive method?
Breastfeeding suppresses GnRH secretion via prolactin (compare anovulation due to hyperprolactinaemia in prolactinomas)
Must be exclusively breastfeeding
In which population is using the progestin-only pill most effective?
If also post-partum breastfeeding
How is the minipill taken?
Taken daily at same time of day to ensure reliable effect
How does the minipill work?
Inhibition of ovulation + cervical mucous changes
What is the mechanism of action of the OCP? (3)
Stops ovulation (through LH and FSH suppression)
Changes lining of uterus to prevent implantation
Thickens cervical mucous resulting in decreased sperm penetration
What are the advantages of using the combined OCP? (7)
- Highly effective if used properly
- Reversible
- Decreased dysmenorrhoea and menorrhagia
- Decreased benign breast disease and ovarian cyst development
- Decreased risk of ovarian cancer
- Improved acne
- Possible osteoporosis protection
List 7 oestrogen-related side effects when taking the OCP.
- Nausea
- Breast changes (tenderness, enlargement)
- Fluid retention/bloating/oedema
- Weight gain (rare)
- Migraine, headaches
- Thromboembolic events
- Breakthrough bleeding - occurs in the first few months after starting, usually resolves after three cycles
List 9 progestin-related side effects when taking the OCP.
- Amenorrhoea/breakthrough bleeding - breakthrough bleeding usually occurs in the first few months after starting, usually resolves after three cycles
- Headaches
- Breast tenderness
- Increased appetite
- Decreased libido
- Mood changes
- Hypertension
- Acne/oily skin
- Hirsutism
List 9 absolute contraindications to taking the OCP
- Known/suspected pregnancy OR less than 6 weeks postpartum
- Undiagnosed abnormal vaginal bleeding
- Prior thromboembolic events OR thromboembolic disorders
- Current or past history of cerebrovascular or coronary artery disease
- Current oestrogen-dependent tumours
- Impaired liver function associated with acute liver disease
- Migraines with focal neurological symptoms
- Uncontrolled hypertension
- Smoker age more than 35 years and smoking more than 15 cigarettes a day
List 4 relative contraindications to taking the OCP
- Migraines - non-focal
- Currently symptomatic gallbladder disease
- Controlled hypertension
- Medications: rifampin (might affect absorption) or anti-epileptics e.g. phenytoin, carbamezapine (hepatic enzyme-inducing drugs (increase metabolism and therefore decreases hormone levels)
What advice is given to women taking OCP and is on rifampicin?
Advice to use condoms concurrently and 28 days after stopping
What advice is given to women who misses pills while on OCP? (3)
Depends on which part of pill pack is missed and how many in a row
- If miss one pill at any point - take missed pill as soon as you remember, take next pill at normal time, condom use not required
- 7 subsequent pills required for sufficient suppression of ovulation - a back-up method of contraception or abstinence should be used if a pill is more than
24 hours late, until 7 consecutive pills have been - If the missed pills are in week 3, the pill-free interval should be missed
What advice is given if woman on progestin-only pills misses dose?
If more than 3 hours, use back-up contraceptive methods for at least 48h. continue to take remainder of pills as prescribed
Describe the use of the contraceptive ring
Thin flexible plastic ring inserted into vagina that releases oestrogen and progesterone - works for 3 weeks than removed for 1 week. As effective of OCP in preventing pregnancy
What is the mechanism of action of a copper IUD?
mild foreign body reaction in endometrium toxic to sperm and alters sperm motility
What is the mechanism of action of a Mirena?
Progesterone-releasing IUD
Decidualisation of endometrium and thickening of cervical mucous; minimal effect on ovulation
When are IUDs suitable to use as a contraceptive?
In women with contraindications to OCPs or wanting long-term contraception
When are progestin-only methods suitable to be used as contraception? (3)
Suitable for postpartum women (does not affect breast milk supply)
Women with contraindications to combined OCP
Women intolerant of oestrogenic side effects of combined OCPs
How does a Depo-Provera work?
Injectable progesterone IM (MDPA) every 12 weeks - can have irregular spotting at first but can progress to complete amenorrhoea.
- Thins lining of uterus - no implantation
- No ovulation
- Thickens cervical mucous - decreases sperm penetration
What options are there for female sterilisation?
Usually permanent/irreversible
Laparoscopic or hysteroscopi tubal occlusion - does not prevent ovulation therefore will still get period.
How effective are the following hormonal forms of contraception?
- OCP
- contraceptive ring
- progestin only pill
- depo-provera
- IUD
All except progestin-only pill have >99% effectiveness
Progestin-only pill = slightly less (1.1-13% failure rate with typical use)
