Contraception and Fertility Flashcards
What are the key hormones in oral contraceptives
Estrogen and progestin
How do combo estrogen progestin OC work
Combinations of estrogen and progestin work by preventing ovulation. They also change the lining of the uterus (womb) to prevent pregnancy from developing and change the mucus at the cervix (opening of the uterus) to prevent sperm from entering.
Two types of preparations for estrogen progestin combo OC
combinations of estrogens and progestins
continuous progestin therapy without concomitant administration of estrogens
Can estrogen be given alone for BC?
No, estrogen-only contraception is not an option due to “unopposed estrogen” causing uterine hyperplasia and eventually uterine cancer! If estrogen is given chronically for birth control, it will always be accomanied by an progestin. In contrast, progestins can be very effective alone for birth control without causing dangerous side effects/adverse events. However, they have to be given in a way that guarantees a relatively constant serum level of progesterone, or breakthrough ovulation occurs and then pregnancy.
What is the most common synthetic estrogen used in BC
Ethinyl estradiol, which has the ethinyl at C-17 to avoid first pass (seen in natural steroid hormones)
What are the two estrogen agonists
Ethinyl estradiol
Mestranol
Progestin that is antiandrogenic and also antimineralcorticoid
Drospirone, derived from 17-alpha spironolactone
Yaz
Hydroxyprogesterone derivatives
Hydroxypregesterone
Medroxypregesterone
19-Nortestosterones
Levonorgestrel
Norethynodrel
Norethindrone/Norethindrone acetate
Ethynodiol
Norgestrel
Norgestimate
Desogestrel
Four types of oral contraception
Instructions for progestin only “minipill”
Critical to take at the same time, every day to maintain a constant level of progesterone receptor activity! Or will fail and result in pregnancy.
What is the recommended first-line BC for most women
Long-acting subdermal implantable or depot forms of progesterone
These are very effective forms of contraception, with the long-acting implantable subdermal forms being even more effective in preventing pregnancy than surgical sterilization of male or female partners.
What is the usual level opf estrogen in combo pills
Typically, the pill with the least amount of estrogen that is still effective is prescribed, due to increase venous thromboembolism (VTE) concerns.
What is mifepristone and what is its mechanism
Progesterone receptor antagonist
Mifepristone has luteolytic properties in 80% of women when given in the midluteal period, but the mechanism is unknown. Mifeprestone has a long half-life, large doses may prolong the follicular phase of the cycle and make it difficult to use continuously as a contraceptive.
Most common use of mifepristone
To terminate early pregnancy
Doses of 400-600 mg/d for 4 days or 800 mg/d for 2 days successfully terminated pregnancies in 85% of women.
What is Plan B
Progestin-only levonorgestrel
What is Ulipristal acetate
A progestin antagonist, may impact sperm motility. Used as emergency contraception
Most effective form of emergency contraception
Copper IUD
What is ulipristal
Selective Progesterone Receptor Modulator - Ulipristal potently antagonizes progesterone receptor. It also binds the androgen and glucocorticoid receptors, but has weak antagonistic activity.
What are the 4 IUDs
ParaGard is a copper containing IUD, FDA-approved for 10 years of use, but shown to be effective for up to 20. No progestin or estrogens in this preparation.
Mirena provides continual release of levonorgestrel is FDA-approved for 5 years (effective for up to 7). Mirena is approved for those with heavy bleeding. It releases 20 mcg/day of levonogestrol initially and tapers to 10 mcg/day.
Skyla is FDA approved for up to 3 years of use. Skyla is slightly smaller which is advantageous for nulliparous women. The smaller device has less reported pain. This preparation initially releases 14 mcg/day and tapers to 5 mcg/day.
Liletta is similar in size to Mirena. It is FDA approved for up to 3 years. Mirena releases 18.6 mcg/day and decreases to 12.6 mcg/day.
What is nexplanon
Arm implant, containing the progestin etonogestrel
What is Medroxyprogesterone acetate
Injectable contraception, injected intramuscularly
Side effects of estrogen
nausea and breast tenderness and enlargement. OC with lower levels of ethinyl estradiol are associated with higher incidence of bleeding disturbances.
What lab tests can be altered with contraceptions
Increased Clotting factors
Lipid alterations
Increased Thyroxine-binding globulin (TBG) and total T4
Drug interactions of significance for BC
anticoagulants, anticonvulsants, antibiotics (rifampin), antiretroviral (Efavirenz)
Tips for too little or too much estrogen and progestin
If the problem is a menstrual irregularity, your probably have a deficiency in one or other of the components.
If the problem is due to excess estrogen, think “ salt and water retention “
If the problem is excess progestin, think “ anabolic/masculinizing side effects of the 19-nortestosterones “ and choose a later generation progesterone
Mild adverse effects of OCPs
Nausea, change in serum proteins, withdrawal bleeding, headache
Moderate adverse effects of OCPs
Breakthrough bleeding, weight gain, increased skin pigmentation, acne, hirsutism, ureteral dialtion, vaginal infections, ammenhorea
Significant side effects of OCPs
Vascular disorders, GI disorders, depression, cancer
Other, less evidence: alopecia, erythema multiforme, erythema nodosum, and other skin disorders
Must ask questions before giving oral contraception
- >35 and smoker
- History of venous thromboembolism (VTE)/strong family history
Contraindications for OC
Organic causes of female infertility
Adrenal (lack of androgen precursor)
Pituitary/hypothalamic dysfunction - lose ovarian stimulation
Anatomic - e.g. obstruction of the Fallopian tubes
Conditions of infertility amenable to pharmacological treatment
What is clomiphene and when is it used
Clomiphene is a partial agonist of the estrogen receptor and inhibits the actions of stronger estrogens. Blocks estradiol’s negative feedback effect on gonadotropins leading to a surge gonadotropin release and ovulation.
used to normalize/reboot feedback communication when anovulation occurs
