contraception的方式很多，有激素（藥物），宮內節育器，物理性隔離（比如condom），化學性隔離（殺精劑），生理避孕，結扎等。 在RN/CGFNS考試中經常會考到這一類的知識，但是有的書上對這些內容描述很不全面，因此我總結了一些相關的避孕方式，副作用，禁忌癥等，希望大家能 掌握這些知識，在考試中能順利地答對題目。

Hormonal contraceptives(pill,避孕藥):
主要包括Estrogen, Progesterone, Androgen
Side effect(especially estrogen):  abnormal menstruation，breast cancer，liver    toxicity, fluid  retension,thromboembolism, migraine headaches 
Contraindication: liver disease, thromboembolic, coronary artery disease, hypertension,decrease in glucose tolerance(diabetics), renal disease, gallbladder disease
note: emergency postcoital contraceptives should be taken within 72 hours of unprotected coitus

Intrauterine devices (IUDs,也就是我們常說的上環)
side effect: Uterine perforation, infection, heavy bleeding, spotting between periods,prolonged periods, cramping
Contraindications: PID, pregnancy, undiagnosed genital bleeding, genital malignancy, abnormal uterine cavity

Diaphragm (避孕隔膜,性交前置入女性陰道內)
No side effects from well-fitted device if woman is not allergic to diaphragm or spermicide
Contraindications: vaginal bleeding , hard to fit, genital infection, allergy,toxic shock syndrome
Note: Insert up to 6 hr before intercourse and leaving in place for 6 hr after last intercourse, but no longer than 24 hr；Size/fit must be checked after term birth, second/third trimester abortion, weight gain or loss of 15-20 Ib, every 2 years；clean with warm water and mild sop, powder with cornstarch and store away from heat

Cervical cap(宮頸帽,性交前置入女性宮頸處,注意事項類似避孕隔膜)
Contraindications: abnormal Pap smear, hard to fit, genital infection, allergy, toxic shock syndrome
Note: Worn for 8 hr but not longer than 48 hr.Size/fit must be checked after term birth, second/third trimester abortion, weight gain or loss of 15-20 Ib, every 2 years
clean with warm water and mild sop, powder with cornstarch and store away from heat
Pap smear every year

Condom(安全套)
No side effect except allergy to latex
Protect from STDs(the only method).
Use with water soluble jelly, cream, spermicidal foam

Spermicide(殺精劑)
Side effecti: allergy
Note: each intercourse should be preceded (30 min) by a fresh application

Natural family planing(自然避孕,安全期避孕)
BBT each morning before any physical activity
Body T decrease slightly when ovulating then decreased 0.5 degree below base T
Requireds sexual abstinence(or use of condom) during woman's fertile period ( 4 days before ovulation and 3-4 days after ovulation)

Ligation(結扎）
Male: Vas deferens is occluded with band or clip to prevent passage of sperm
side effect: some men become impotent due to psychological response to procedure, fertility after tubal reconstruction
Female: Both fallopian tubes are ligated and severed with bands or clip to prevent passage of eggs.
complications: infection, hemorrhage, trauma to other organs