Contraception (Week 7--Davtyan)

Question 1

Contraception use and unplanned pregnancies

Answer 1

1 in 10 don’t use contraception

6 in 10 pregnancies unplanned (3 million annually)

53% unplanned pregnancies happen in women who “use” contraception

Question 2

Likelihood of pregnancy if no contraceptive method

Answer 2

85%

Compared to 12.5% if using reversible method of contraception

Question 3

Methods of withdrawal and abstinence during fertile phase of menstrual cycle

Answer 3

Fertile phase is 4 days before ovulation and 1 day after

Calendar

Symptothermal (body temp, ovulation related symptoms)

Ovulation prediction kit (detects LH surge via urine or saliva)

Electronic fertility monitor (detects estrogen metabolites and LH surge)

Question 4

Barrier methods

Answer 4

Spermicides (nonoxyl-9: sponge, gel, cream, film, vaginal tablet)

Condom

Diaphragm (take out within 6 hours to prevent TSS)

Cervical cap

Femcap (can be left in for 24 hours)

Lea’s shield (one way valve lets out cervical secretions)

Question 5

Male sterilization

Answer 5

Vasectomy

Vasclip (less bleeding and less pain but still effective)

Question 6

Surgical female sterilization

Answer 6

Tubal ligation (interrupt fallopian tube)

Risk: higher than vasectomy because requires general anesthesia

Question 7

Nonsurgical female sterilization

Answer 7

Essure: place metallic microcoil in both fallopian tubes and get a fibrotic/foreign body response to occlude tubes; within 6 months 100% patients occluded (came out 2002)

Adiana: place polymer matrix in proximal fallopian tube then use radiofrequency to stimulate vascular tissue growth; 98.9% effective (came out 2009)

Question 8

Intrauterine device (IUD)

Answer 8

ParaGard: works for 10 years; copper; mechanism not understood but prevents implantation (prostaglandins could allow uterine contractions?)

Mirena: works for 5 years; protestin

Question 9

Hormonal oral contraception

Answer 9

Targets pituitary LH and FSH–keep these low so no ovulation can occur

Estrogen and Progestin daily with 7 out of 28 inactive

Progestin daily

Extended cycle–can even take continuous E and P (in 66% have amenorrhea after a few months but spotting/bleeding can occur in others)

Question 10

Other non-oral hormonal contraceptives

Answer 10

Depo-Provera, DMPA-104 injection (progestin IM every 3 months; SQ every month)

Implanon (SQ progestin implant)

OrthoEvra (E and P patch to change weekly)

Nuvaring (E and P vaginal ring to change monthly)

Question 11

Emergency contraception

Answer 11

Within 2-3 days (up to 5 days) after unprotected intercourse has 75% efficacy in preventing pregnancy

Preven: 2 doses of E and P 12 hours

Plan B: 2 doses P 2 hours apart or 1 high dose progestin (OTC for women older than 17 only)

IUD within 5 days of intercourse prevents implantation

RU-486 (Mifepristone) effective but not in clinical use (is progesterone antagonist)

EllaOne delays ovulation via LH inhibition but if have already ovulated this will not work; works 5 days after sex (selective progesterone receptor modulator–agonist and antagonist depending on tissue)

Question 12

Risks of E and P hormonal contraceptives

Answer 12

Breast cancer: no increase if older than 35, small increase if younger than 35

Cardiovascular (stroke, MI): no increased risk with low dose in normotensive nonsmokers

Venous thromboembolism: yes, very small risk but lower risk than if you’re pregnant

Question 13

Benefits of E and P hormonal contraceptives

Answer 13

Improvement of menstrual/premenstrual symptoms

Preserves bone density

Improvement in rheumatoid arthritis

Improves symptoms of acne, hirsutism, endometriosis, fibroids, ovarian cysts, benigh breast diseases, PCOS

Reduces risk for uterine, ovarian, colorectal cancer

No weight gain (only w/injectable progestin)

Question 14

Categories of safety

Answer 14

Category 1: no restriction

Category 2: advantages outweigh risks (OCP for smoker under 35)

Category 3: risks outweigh advantages (smoker older than 35, less than 15 cigarettes per day)

Category 4: method unacceptable with risk (smoker older than 35, more than 15 cigarettes per day)

Question 15

What are FSH and LH levels like on a patient taking OCP?

Answer 15

FSH and LH are high right after menstruation but get suppressed and decrease throughout the 21 “on” days

When you start taking placebo pills, FSH and LH shoot up

If you miss a pill, small LH surge could cause ovulation

Since you never have a CL, you never have an increase in progesterone

Question 16

Why does method of drug delivery matter (OCP vs. patch vs. vaginal ring)?

Answer 16

OCP is metabolized daily so get peak when you take it (30ug), then decreases throughout the day (peaks every day)

Patch is constant moderate supply (20ug)

Vaginal ring (Mirena IUD similar) is constant low supply (15ug)

Since estradiol is what causes most of side effects, pill is probably worst and vaginal ring the best

Question 17

Progestin-only contraception

Answer 17

Attenuates peak levels of LH surge and pre-ovulatory rise in estradiol

Blocks ovulation in most patients (not all)

Thickens cervical mucus

Decreases thickness of uterine endometrial wall

(multiple effects that prevent pregnancy even if ovulation does occur!!)

However, some patients get naueous with progestin only (with pill, this reduces compliance!)