23 - Contraception Flashcards
What do contraceptives do
block “conception” of a fetus
work to keep sperm and ovum from being united
What do contra-gestational agents
they work to keep the fertilized egg from implanting
What do abortifacients do
they cause the termination of an established pregnancy
How to prevent pregnancy at the transport of viable sperm
vasectomy
How to prevent pregnancy at the deposit of sperm in vagina
condom or coitus interrptus
How to prevent pregnancy at the survival of sperm in vagina
spermicides
How to prevent pregnancy at the movement of sperm to uterine tubes
cervical cap
Diaphragm
How to prevent pregnancy at the production of viable
oral contraceptives (OCs)
How to prevent pregnancy at ovulation
oral contraceptives
How to prevent pregnancy at movement of oocytes to uterine tubes
tubal ligation
How to prevent pregnancy at the implantation of zygote
MAP, OCs, IUDs
How to prevent pregnancy at growth of the embryo/fetus
abortion, surgical (D&C)
or medical (RU 486)
What are the calendar methods of birth control
Rhythm Method:
- practicing abstinence from sexual intercourse (usually 3 days before and 3 days after) the likely date of ovulation
Fertility Awareness:
- relies on noticing the signs of ovulation
–> a slight drop in body temperature occurs just before ovulation and a slight increase occurs after ovulation
–> cervix produced a thin, clear, watery, and elastic mucus that shows maximal ferning
–> ovulation is associated with mittelschmerz (one-sided, cyclical abdominal pain)
–> position of cervix changes throughout the menstural cycle
What are oral contraceptives, what do they do
combination pills
- combine an estrogen and a progestin
- they suppress the hypothalamic-pituitary-gonadal axis
- the estrogen and progestin inhibit the release of GnRH
- low FSH = little follicular development
- no LH surge = no ovulation
What are the combined steroid contraceptives
contraceptive patches (Evra)
- work the same as pills except the delivery of steroids is transdermal
- difficult to be noncompliant with this system unless the patch falls off
- patch is put on once a week
contraceptive ring (Nuvaring)
- placed in the vagina for three weeks and removed for one
- does not provide any sort of a barrier to the movement of sperm – it is just a way of delivering steroids
What are progestin only contraceptives
formulated to avoid the side effects of estrogen
do not reliably suppress ovulation but cause thick and scanty cervical mucus and prevent the movment of sperm across the cervix
endometrium is kept in a “pseudo-pregnant”/atrophic state which hinders the implantation fo the zygote
What are the forms of progestin only contraceptives
mini-pills
injectable
IUD
implant
Describe the mini pill
use a synthetic progesterone (progestin)
taken PO every day except for 7 days in a 28 day cycle
risk of contraceptive is failure greater than combination pills
Describe the depo-provera
use of synthetic progesterone given IM to the buttock or deltoid
What are the risks of progestin only contraceptives
increased risk of abnormal uterine bleeding (AUB) – iatrogenic cause
decreased libido
slightly more ectopic pregnancies
physiology centers on:
- stimulation of endometrial growth by estrogens
- stimulates estradiol conversion to estrone
- decreases estrogen production by inhibiting
What are the postcoital contraception
high dose progestin (plan B)
- administered within 72 hours of coitus and two pills are taken (one right away, other within 12 hours)
- 90% effective
- appears to inhibit natural progesterone and estrogen production
Selective progesterone receptor modulator (SPRM)
- prevent ovulation
- alter endometrial physiology
What are medical abortion
Mifepristone: antagonizes the effects of progesterone
- progesterone causes the uterus to be quiescent, then antagonism causes the myometrium to become active
- often a prostaglandin is often given to increase uterine contractions
=
What is a vasectomy
less invasive surgery
