Contraception Flashcards
Details about reproductive hormones and contraceptive methods available for use
What is meant by the follicular and luteal phases?
Follicular - days 1 - 14 when there is growth and development of the follicle within the ovary (leading follicle becomes prominent) Luteal phase - days 14-28 when the ovum is released from the mature follicle (ovulation) and there is development of the corpus luteum from the empty follicle.
When will menses occur?
after day 28 if there has been no fertilisation of the ovum. The corpus luteum will degrade (no more progesterone) and endometrial lining will be shed
Describe the pattern of LH and FSH through the follicular and luteal phases?
FSH levels are higher during the follicular phase There is a peak in both but LH will surpass FSH at ovulation (day 14) Levels will both decrease but FSH slightly higher during the luteal phase.
What happens to oestradiol during ovulation?
During the follicular phase there is a steady increase in levels, a sharp fall at ovulation then occurs followed by a gradual increase and decrease back to baseline during the luteal phase. Gradually increases through menses.
What happens to Progesterone during ovulation
Will remain at baseline throughout the follicular phase and ovulation. Will then increase significantly during the luteal phase (due to corpus luteum) and decrease again if no pregnancy and menses begins.
Why is there a peak in oestradiol prior to ovulation?
This will stimulate the release of LH and FSH and thus cause ovum release from follicle.
Give some examples of natural contraceptive methods?
Basal body temperature (if taken in morning there will be an increase in temp 0.2 degrees 3 days before and 6 days after ovulation) Cervical mucous will become sticky and thick post ovulation Breast feeding Lower and closed cervix when less fertile
How long can sperm and ovum live in the genital tract for?
Sperm = 5 days Ovum = 17-24hrs
What are the conditions for breast feeding to be 98% effective as a contraceptive?
Must be exclusively breast feeding Must be <6 months post-partum Must be amenorrhagic
How does the combined oral contraceptive pill work?
Releases oestrogen and progesterone to inhibit ovulation and trick the body into thinking you’re pregnant when you’re not (rigevidon or co-cyprodiol)
What is the failure rate of the COCP?
0.2% but in practice probably more like 9% as poor compliance and not taken as should
When should the COCP NOT be prescribed?
FHx or risk of VTE, stroke, clotting disorders etc > 35 yrs old with risk factors Migraine with aura (as will increase risk of stroke) Breast cancer hx or cervical cancer hx Within 6 weeks post-partum as increased VTE risk
What is the effect of oestrogen on clotting?
Will block anti-thrombin 3 and protein s (inhibit anti-coagulation)
What can the COCP help with?
Functional ovarian cysts, PCOS, premenstual syndrome, acne
Which cancers does COCP reduce risk of?
Endometrial and ovarian
What is the progesterone only pill?
Contraceptive pill without oestrogen - newer versions have desogestrol
How does the POP work?
Mainly by inhibiting ovulation (tricky body into think pregnant) but also makes cervical mucous sticky, endometrium less favourable and effects fallopian tube transport.
What are side effects of the COCP?
Bloating, mood changes, bleeding, systemic hypertension (need to check at 3 months from starting)
How should COCP be taken?
If taken within 5 days of starting period then effects are immediate, if not then 7 days to kick in. Can run packs together as bleed is actually just a withdrawal from the hormone (not real period).
What hormone(s) are released in the sub-dermal implant?
Progesterone - inhibitis ovulation, effects on cervical mucous, endometrium and fallopian tube mobility
Give example of the implant
Nexplanon
What are the effects of the IUS?
Miruna and Jaydess are the two types available Release of progestrogen so will cause cervical mucous thickening, endometrial thinning, can prevent ovulation
How long can the IUS be left for?
5 years
What is the failure rate of the IUS
0.2% (incorrect positioning)
What is the failure rate of the sub-dermal implant?
0.05%
How does the Cu-IUD work?
Copper will cause an inflammatory response in the endometrium (unfavourable for implantation) and will also be toxic to sperm.
How long can the Cu-IUD be left in for and what are its failure rates?
5-10 years 0.6-0.8% failure rate
Discuss female and male sterilisation
Male is more effective than female Females require an abdominal surgery whereas males is a non-invasive surgery Need to be absolutely sure not pregnant or ovum in fallopian tube as can cause an ectopic pregnancy
What should you ALWAYS do before prescribing contraceptives?
Sexual history - need to know if currently pregnant BMI and BP
What can make you reasonably certain that a patient is not pregnant?
No sex since last period Taking contraception reliably <7 days since last period <4 weeks post-partum (not breast feeding) <6 months post partum (breast feeding and amenohorragic) Negative pregnancy test and >3weeks since UPSI
What can be given as emergency contraception?
Copper IUD (10x more effective than oral) LNG-EC UPA-EC
How does LNG-EC work
High dose of progesterone given to prevent ovulation - does not work after ovulation or during LH surge effective for up to 72hrs after UPSI (will decrease in efficacy after 24hrs)
How does UPA-EC work?
Works as an antiprogestrogen Will be active for up to 120hrs after UPSI and is effective during LH surge (not ovulation though) Will be 85% effective over all 5 days Contraception (oral) will interfere with it’s action so avoid if on already
What must you do if giving oral contraceptive after administering UPA-EC?
delay oral contraceptive by 5 days
Give example of an LNG-EC and UPA-EC
levonelle and ullipristal acetate
