Contraception Flashcards
What is GnRH?
Causes the release of FSH and LH from the pituitary
What is FSH?
Follicle stimulating hormone, which stimulates the maturation of follicles in the ovaries
What is Estrogen? (Estradiol)
Stimulates thickening of the endometrium
Suppresses FSH
What is LH?
Luteinizing hormone which stimulates and triggers ovulation
What is progesterone?
Makes endometrium favourable for implantation
Signals the hypothalamus and pituitary to stop FSH and LH production
What are the phases of menstrual cycle?
Day 1: First day of period
Days 1-4 Increase FSH leading to follicle growth/development
Days 5-7
One follicle becomes dominant and estrogen productions occurs
Increase production of thin water cervical mucous
What is the Fertile window?
When we see the highest amounts of LH and FSH
What hormone causes the stimulation of the pituitary to release a mid cycle surge of LH?
Estrogen levels
How long after LH surge does ovulation occur?
28-32 hours
What is the luteal phase?
Released ovum travels through fallopian tubes and to the uterus
If implantation occurs what happens to the corpus luteum?
Corpus luteum continues to produce progesterone
If not implantation occurs what happens to the corpus luteum?
It deteriorates and stops producing progesterone
What occurs from the luteal phase to follicular phase?
Progesterone levels decrease and the endometrial lining is shedding leading to release of GnRH to start the cycle again
What are the 4 contraception methods?
Hormonal
Barrier
Permanent
Natural family planning
What are the two forms of estrogen available in hormonal contraceptives?
Ethinyl estradiol (EE)
Estetrol
What are progestins?
These are progesterone like structures that are synthetic hormones that activate progesterone receptors
How many generations of progestins are there?
4 where each generation is thought to be a bit better then the previous
What is the main role of estrogen and progestion?
To provide a negative feedback which inhibits ovulation
What does estrogen do?
It suppresses release of FSH
What does progestin do?
Suppresses release of LH and FSH
Thickens cervical mucus
Changes endometrial lining
What are the categories of hormonal contraception?
Combined
Progestin-only
Long-acting reversible contraception
What is phasic formulations of OC?
Biphasic. Fixed E, Increased P
Triphasic Fixed or variable EE, Increased P
What is extended dosing?
Planned Hormone free interval where we continue taking oral contraception for 84 days then go 7 days of either 10mg EE or HFI
When is the most effective day to start the pill?
Day 1 of period
If you start the pill not on day one what is important?
Use backup birth control for the first 7 days to suppress ovulation
What is the typical failure rate of OC?
3-8%
What are the common counselling components that you should tell patients starting the pill?
First 3 months
Breakthrough bleeding
Breast tenderness
Nausea
What dose of estrogen leads to nausea?
> 50mcg
How do we decrease breast tenderness S/E?
Decrease estrogen
What do we do in patients who experience break through bleeding?
Increase dosages of EE/P, if greater then 6 months consider other causes such as STI
What are some other potential adverse effects of taking the pill?
Weight Gain
headache and migraine
Mood changes
Acne
What are the potential benefits of being placed on BC?
Improve menstrual symptoms and PMS symptoms
Decrease incidence of endometriosis
Ovarian cancer
Osteoperosis
When do we usually see contraceptive failures?
Missed pills of less then 20mcg estrogen
What is the risk of venous thromboembolism with taking OC?
Risk is 2-3x higher than in non user
What are other risks that contribute to VT?
Increase risk with age
Increase risk with smoking and estrogen combination
What leads to an increased risk of MI and stroke?
Estrogen >50mcg day, >35 yrs, smoking, HTN, other CVD
What is the acronym ACHES
What are the three main types of potential drug interactions with BC?
enterohepatic circulation of oral contraceptives
Drugs that induce metabolism of oral contraceptives
drugs that have their metabolism altered by oral contraceptives
What enzyme induces and increases metabolism of BC?
CPY450 3A4
What medications are CYP450 3A4 inducers?
Anticonvulsants
Anti-infectives
Herbals
Which anticonvulsants increase metabolism of OC?
Carbamezapine, phenytoin
What anti-infectives increase metabolism of OC?
rifampin
How do we manage medications that increase metabolism of OC?
Increase Estrogen levels of OC
Used extended dosing
use alternative to interacting drug or other methods of birth control
What is the anti-convulsant that we need to be aware of with OC?
Lamotrigine as OC significantly decreases levels
If someone has migraine with aura what are we worried about?
Increased risk of blood clots with OC. directly CI
What hypertension level is CI with OC?
160/100
How long after post partum is OC CI?
3-6 weeks due to increase VTE, AND we want to establish breast feeding
What is the efficacy of the patch when not used properly?
typical use is 8%
How long does a patch last?
7 days
If you apply patch other then day 1 what should be councelled?
7 days of back up contraception
Where can patches be applied?
upper arm, buttocks, lower abdomen, upper torso
What can occur in the first 2 cycles of patch usage?
Increased spotting
What weight is the patch deemed less effective?
> 90kg and increase risk of blood clots
What is the nuvaring?
Inserted vaginally