Lecture 12 - Contraception And Fertility Flashcards
What are the 3 main methods of contraception?
Blocking sperm transport (cervical mucus)
Disrupting HPG axis preventing OVULATION
Inhibiting implantation of conceptus into endometrium (thinning endometrium)
What are the categories of contraception?
Natural
Barrier
Hormonal
Intrauterine (IUD/IUS)
Sterilisation
Emergency contraception
What are some natural methods of contraception?
Abstinence
Withdrawal
Fertility awareness methods
Lactational amenorrhoea
What are the advantages of abstinence as a contraception method?
100% effective
What are the disadvantages for abstinence as a method of contraception?
Not an option for most
Unprepared when sexually active
What are the advantages and disadvantages of using the withdrawal method for contraception?
Adv:
-no devices or hormones
Disadvantage:
-unreliable (some sperm in pre-ejaculate)
-No STI protection
What is the natural fertility awareness method of contraception??
By using cervical secretions and basal body temperature changes can work out what stage in the cycle they’re at and therefore when they’re most fertile or not
What happens to the basal body temperature at ovulation?
Lots of progesterone produced by the corpus luteum, this leads to an increase in Basal Metabolic Rate which increases the body temperature
What are the advantages and disadvantages of using the fertility awareness methods as contraception?
Adv:
-no hormonal/contraindications
Disav:
-time consuming
-unreliable
-no sti protection
-not suitable for everyone
How do cervical secretions change during the cycle?
What hormones are high in these phases?
Follicular phase;
-high oestrogen
-thin alkaline cervical mucus
Luteal phase:
-high progesterone
-thick sticky acidic cervical mucus
How does lactational amenorrhoea work as contraception?
When lactating up to 6 months postnatal Prolactin levels are very high
Prolactin inhibits GnRH release
This inhibits production of sex hormones
What are the advantages and disadvantages of the lactational amenorrhoea method of contraception?
Adv:
-no hormonal/contraindications
Disadvantage:
-unreliable after 6 months
-No STI protection
-not suitable for all
What are some barrier methods of contraception?
Condoms
Diaphragms/cervical caps
Spermicides
What are the advantages and disadvantages of the barrier method of contraception?
Adv:
Reliable (if used correctly)
-STI protection
Disadvantage:
-disrupts intercourse
-risk of dislodging
-allergy to latex
What does the combined oral contraceptive pill contain? (COCP)
Oestrogen and progesterone
What is the main action of how the combined oral contraceptive pill works?
What is its secondary actions?
STOPS OVULATION
Secondary:
-thins endometrium
-thickens cervical mucus
What are the advantages of the Combined oral contraceptive pill?
Reliable
Can relieve menstrual disorders (can take back to back to prevent periods helping with endometriosis)
Decreased risk of ovarian cancer (less ovulation) and endometrial cancer (reduced proliferation of endometrium)
Reduced acne severity
What are the disadvantages of using the combined oral contraceptive pill (COCP)?
User dependant
No STI protection
Medication interaction
Contraindications (raised BMI, migraines, breast cancer)
Side effects = menstrual irregularities, breast tenderness and mood disturbance
Inc risk of CV disease, stroke, VTE, breast and cervical cancer
What is the action of high dose progesterone?
Enhances negative feedback of oestrogen
So low oestrogen means low FSH and LH
This prevents the LH surge leading to ovulation
Prevents ovulation by preventing LH surge
What is the action of lower levels of progesterone?
Thickens cervical mucus
Ovulation still occurs since the progesterone is not high enough to inhibit oestrogen enough to prevent LH surge
What are the levels of progesterone in the progesterone only pill (POP)?
Low dose progesterone taken daily
What is the main method of action of the progesterone only pill if its low dose progesterone?
Thickens cervical mucus
Secondary:
Reduced cilia activity in fallopian tubes
OVULATION is NOT prevented
What are the advantages of the progesterone only pill?
Reliable
Can be used if the COCP contraindicated
What are the disadvantages of the progesterone only pill?
No STI protection
Strict timing
Menstrual irregularities
Inc risk of Ectopic pregnancy
The progesterone causes menstrual side effects (mood swings, acne)
What is the progesterone injection?
High dose progesterone
(LARC)
Long acting reversible contraception
Given IM every 3months
What are the main actions of the progesterone injection?
INHIBITS OVULATION (inhibits LH surge by inhibiting oestrogen)
Thickens cervical mucus
Thins endometrial lining