Contraception Flashcards
1
Q
What are contraceptives?
A
- block conception of a fetus
- keep sperm and egg from becoming united
- eg. combo OC pills, mini-pills, progesterone injections, contraceptive patches, and mechanical methods like caps and condoms
2
Q
What are contragestational agents?
A
- keep gestation from occuring
- work to keep fertilized egg/zygote from implanting
- IUD, morning after pill
3
Q
What are abortifacients?
A
- cause the termination of an established pregnancy
- mifepristone, mechanical means of abortion
4
Q
What are the necessary steps that need to happen to become pregnant? How can these steps be interrupted?
A
- production of viable sperm
- transport of viable sperm (vasectomy)
- deposit into the posterior fornix of vagina (condoms or coitus interruptus)
- survival of sperm in vagina before going up cervix and into uterine tubes (spermicide)
- movement of sperm into uterine tubes (cervical cap and diaphragm to block entry through cervix)
- production of viable oocytes (OC pills)
- ovulation (OC pills)
- movement of oocytes to uterine tube (tubal ligation)
- fertilization of oocyte with sperm
- implantation of oocyte (MAPs, OCs, IUDs)
- growth of embryo/fetus (abortion- surgical or medical)
5
Q
Describe the preparation of the endometrium
A
- menstrual phase (day 1-4) where functionalis layer comes off
- proliferative phase (day 4-14) driven by the development of the oocytes from primary into secondary follicles
- secondary follicles make estrogens which causes endometrium to grow (more vascularization and glands), cervical mucus is thin
- corpus hemorrhagicum at 14 days which signals beginning of secretory phase
- corpus luteum makes estrogen and progesterone
- uterine gland cells are producing the maximal amount of secretions for the zygote and the cervical mucus is thick
6
Q
What are calendar methods of birth control (fertility awareness)?
A
- fertility awareness relies on noticing the signs of ovulation
- slight drop in body temperature occurs just before ovulation and slight increase in body temperature that occurs after
- production of thin, clear, watery and elastic cervical mucus (max spinnbarkeit) that shows maximal ferning
- mittelschmerz (one-sided cyclical abdominal pain associated with ovulation)
- position of the cervix (lower harder cervix=less fertile, elevated, softer and wetter cervix= more fertile)
- intercourse has to be planned around the times when ovulation is not going to occur
- a number of cycles have to be recorded to be reasonably sure that the cycle is regular
- about a 20% failure rate per year though with perfect use it could be 2% (sex drive is up during ovulation so perfect use can be hard, other things can alter cervical mucus that aren’t ovulation)
7
Q
What are calendar methods of birth control (rhythm method)?
A
- practice abstinence from sexual intercourse 3 days before and 3 days after likely date of ovulation
- date of ovulation determined from menstrual cycles
- failure rate is 9% per year but more like 25% in typical use
8
Q
What is a symptothermal chart?
A
- body temperature is recorded; around day 13-14 temperature dipped and increased indicating ovulation
- blood during menstrual phase, no discharge in proliferative phase, discharge because of thin cervical mucus, at ovulation becomes wet, clear, and slippery, after ovulation flip flops between discharge/no discharge and discharge becomes dry/pasty/cloudy which means it is unlikely sperm will get through
9
Q
What is cervical mucus ferning?
A
- when cervical mucus dries it makes ferning pattern from crystals
- fertility awareness method can rely on this
- if you are infertile, the cervical mucus won’t fern up
- can look at it with a fertile focus
- these methods can be popular because they monitor the normal cycle rather than changing it (OCs, patch, and injection look to manipulate hormone levels and ovarian/uterine cycles)
10
Q
How do combination pills function?
A
- combine an estrogen and a progestin to create a psuedopregnancy
- estrogen and progestin inhibit release of GnRH
- this suppresses hypothalamo-pituitary-gonadal axis; low GnRH-low FSH/LH-little follicle development/no LH surge (no ovulation)
- create a thick cervical mucus which inhibits sperm migration
- “hostile” endometrium
- the endometrium is not in the secretory phase (it is atrophic) thus it does not allow the zygote to implant
- endometrium does not build up because the combo of estrogen and progestin is not what you need to grow endometrium
- endometrium is thin like this in pregnancy
- one of the most effective reversible types of birth control
- failure is 0.7 per woman years
- one or two pills are enough to cause the endometrium to proliferate and allow ovulation
- most combination preparations involve taking 21 days of hormones and 7 days without hormones where endometrium will likely come off (withdrawal bleed)
- some pills have extended the time between withdrawal bleeds
11
Q
Why do the combination pills cause women to have more bleeding episodes than in history?
A
- historically, women married and started having intercourse young
- they would get pregnant then exclusively breastfeed the child
- effects of prolactin during breastfeeding prevent ovulation
- every few years a child would come along
- relatively few cycles because they are pregnant and lacting more often
12
Q
How does the contraceptive patch work?
A
- work the same as OC except the delivery of steroids is transdermal
- this should allow for low levels of steroids since the drug enters the system very slowly
- it is hard to be uncompliant with this system unless the patch falls off
- the patch is put on once a week
13
Q
How does the contraceptive ring work?
A
- combined steroid contraceptives
- it is put into the vagina for three weeks and removed for one
- it does not provide any sort of barrier to the movement of the sperm, it is just a way to deliver steroids
14
Q
What are injectable combined contraceptives?
A
- medroxyprogesterone acetate and estradiol cypionate are combined in a once monthly injection
- sold as Lunelle or Cyclofem
- not available in US or Canada though it was available for a while in the US
15
Q
What is progestin-only contraception?
A
- formulated to avoid the side effects of estrogen (mainly nausea and vomiting but also breast tenderness and increased rates of deep vein thrombosis)
- do not reliably suppress ovulation but cause thick and scanty cervical mucus and prevent the movement of sperm across the cervix
- the endometrium is also kept in a pregnant or atrophic state which will not usually allow a zygote to implant
24
Q
What is postcoital contraception?
A
- Morning After Pills (MAPs) or Emergency Contraceptive Pills (EPC)
- high dose progestin (Plan B):
- administered within 72 hours of coitus and two pills are taken, one right away and the other within 12 hours
- it is about 90% effective (instead of a 6-8% chance of becoming pregnant you have a 1% chance)
- appears to inhibit natural progesterone and estrogen production and ovulation
- selective progesterone receptor modulator (SPRM):
- ulipristal acetate blocks the progesterone receptors and thus the effects of progesterone (uterus becomes irritable and endometrium stops being secretory) and inhibits ovulation for a number of days (inhibits LH and FSH surge)
- an IUD can also be fitted after unprotected intercourse
31
Q
What is an essure?
A
- inserted into the isthmus of the uterine tube
- a non-surgical transcervical or hysteroscopic procedure
- causes an essentially irreversible obstruction in the uterine tube when scars form over the inserts
- can be surgically reversed but fertility may not be restored and there is a chance of tubal and uterine penetration because of erosion
- spring expands and work its way through the wall
- removed from market in 2018
