7 Flashcards
What is contraception?
- any method to prevent pregnancy
- blocking transport of sperm to avoid fertilization of oocyte
- Disrupting the HPG axis to interfere with ovulation
- Inhibiting implantation of the conceptus into endometrium
Broadly, what are the methods of contraception?
- Natural
- Barrier
- Hormonal Control
- Prevention of implantation
- Sterilisation
- Emergency contraception
What are the different types of natural contraception?
- abstinence
- withdrawal method
- fertility awareness method
- lactation always amenorrhoea
What is abstinence? Explain the advantages and disadvantages
-only reliable method of contraception, just dont have sex
Advantage
-only 100% reliable method of contraception
Disadvantage
-nothing
What is the withdrawal method? Explain the advantages and disadvantages
-withdrawing before ejaculation
Advantage
-no device/hormones
Disadvantage
- not reliable
- will male have “will power” to withdraw on time?
- some sperm may be released in the pre-ejaculate
- no protection for STI’s
What is the fertility awareness method? Explain the advantages and disadvantages?
- use of fertility indicators to identify fertile and infertile points of the menstrual cycle
- monitor basal body temperature, avoid intercourse around the time of ovulation, monitoring cervical mucus, length of menstrual cycle
Advantage
-no hormones/contraindications
Disadvantages
- unreliable
- no protection from STI’s
What is lactational amenorrhoea? What are the advantages and disadvanatages?
-breastfeeding delays the return of ovulation after childbirth
-hypothalamus is “switched off” because of sucking response and high levels of prolactin
-disrupts release of GnRH
-relies exclusively on breast feeding
Only effective up to 6 months after giving birth
-female must be amenorrheic
Advantage
-no hormones/contraindications
Disadvantages
- unreliable
- no STI prevention
What is barrier contraception? What are the advantages and disadvantages?
- barrier to sperm entering the cervix
- physical barriers: male/female condoms, diaphragm/cap
- chemical barrier: spermicide
Advantage
- reliable: 98% effective (if used correctly)
- protection from STIs
- male condom is widely available
Disadvantage
- “disrupts romantic nature of sexual intercourse”
- “reduce sexual pleasure”
- danger of expiring!
- allergy/sensitivity to latex/spermicide
What is hormonal contraception?
- can be divided into short acting and long acting reversible hormonal contraception
- aim is to disrupt HPG axis to prevent ovulation
- may have additional effects on endometrial lining
What are two common short acting reversible contraception?
- progesterone only pill (POP)
- combined oral contraceptive pill (COCP)
What is the progesterone only pill? What are the advances and disadvantages?
- low dose of progesterone which is not enough to inhibit ovulation
- taken every day, w/o break
- principal action: thicken cervical mucus
- can be more than 99% effective if taken correctly
Advantage
- quickly reversible
- doesn’t interrupt sexual intercourse
- can be used where the COCP is contraindicated
Disadvantage
- user dependant!
- menstrual problems are common
- interacts with other medication
- risk of ectopic pregnancy
- doesn’t protect from STI’s
- missed pill rules
What is the combined oral contraceptive pill? What are the advantages/disadvantages?
-contains synthetic oestrogen and progestogen
-various types in varying strengths
-principal action: prevents ovulation
By tricking the hypothalamus in thinking it is in luteal phase
-secondary action: reduce endometrial receptivity to inhibit implantation, thicken cervical mucus to inhibit penetration of sperm
-taken for either 21 days followed by 7 day break or 21 days with 7 day placebo pill
Advantage
- 98% effective
- can relieve menstrual disorders
- reduces risk of ovarian cysts
- reduces risk of ovarian cancer and endometrial cancer
Disadvantage
- no protection from STIs
- contraindications: ex. BMI, migraine, breast cancer
- side effects: breakthrough bleeding, breast tenderness, mood disturbance
- increased risk of: breast and cervical cancer, VTE, MI/stroke
What are two long acting reversible contraceptives?
- progesterone injection
- progesterone implant
What is progestogen?
Synthetic progesterone
What is the progestogen injection?
- Intramuscular injection of high progestogen given in intervals
- principal action: prevent ovulation
- secondary action: thickens cervical mucus, prevents endometrial proliferation
Advantage:
- reliable: eliminates risk of user failure
- doesn’t disrupt sexual intercourse
- can be useful for women who cant have oestrogen contraceptives
Disadvantage
- appointment needed every 12 weeks
- contraindications and side effects
- delay in fertility returning
- no STI protection