Contraception Flashcards
What is the pearl index (PI)?
measure of a contraception risk of pregnancy per 100 woman-years of using the given contraception method
How is contraception affected in breast feeding women?
• In a women is who fully breastfeeding, amenorrhoeic and less than 6 months postpartum- breastfeeding is
>98% effective at preventing pregnancy
• If a women has unprotected sex <21 days postpartum she will not require emergency contraception
• The COCP affects breastmilk volume and is avoided before 6 weeks postpartum- relatively contraindicated between 6 weeks and 6 months postpartum
• Progesterone-only methods have no effect on milk production
• The IUD can be inserted from 4 weeks postpartum
How does contraception change in later life?
- Women <50yrs should continue contraception for at least 2 years after the last period
- Women >50yrs should continue contraception for 1 year after the last period
What are the types of hormonal contraception?
o Progestogen as a tablet- POP ‘mini-pill’
o Progeston as a depot- Nexplanon, Depo-Provera or in the levonorgestrel-containing IUS
o Combined hormonal contraception (CHC)
COC- mono/bi/triphasic pill
Transdermal patch
Vaginal ring
How do COCP work?
• COCs act by exerting –ve feedback on gonadotrophin release and thereby inhibiting ovulation
they also thin the endometrium and thicken cervical mucus
• Most COC preparations contain a synthetic oestrogen (ethinyloestradiol)- newer COCs (Qlaira or Zoely) contain natural oestrogen (oestradiol valerate) which is metabolised to the naturally occurring oestradiol in the body
How are COCP taken?
• A single tablet, containing oestrogen and progestogen is taken every day for 3 weeks- then stopped for 1 week
• Vaginal bleeding occurs at the end of the pill packet as a result of hormone withdrawal on the endometrium-the cycle is then restarted
• Pill packets can be take consecutively without a break to reduce the frequency of the withdrawal bleed although increased irregular spotting may occur
Failure rate of 0.2 per 100 woman years
What is the COCP also useful for?
o Menstrual cycle control o Menorrhagia o Premenstrual symptoms o Dysmenorrhoea o Acne/hirsutism o Recurrent simple ovarian cysts o Protection against endometriosis & fibroids o Reduced risk of PID Reduced incidence of ovarian, endometrial and bowel CA
When can reduced absorption of the COCP occur?
suffering from diarrhoea, vomiting or taking some oral antibiotics
What are the major complications of the COCP?
o Venous thrombosis o Myocardial infarction o Cerebrovascular accidents o Focal migraine o Hypertension o Jaundice o Liver, cervical and breast carcinoma
What are the side effects of the COCP?
o Nausea
o Headache
o Breast tenderness
o Breakthrough bleeding- first few months
o Suppressed lactation- contraindicated <6 weeks postpartum
What is the combines transdermal patch?
Evra
released ethinyoestradiol plus the progestogen norelgestromin
• A new patch is applied weekly for 3 consecutive weeks- followed by a patch-free week
• Efficacy, side effects and contraindications are similar to the COCP
What is the combined vaginal ring? (Nuvaring)
- Latex-free Nuvaring releases a daily dose of erthinyloestradiol and etonogestrel to inhibit ovulation
- It is easily inserted into the vagina by patient- worn for 3 weeks, then removed to allow for a 7-day ring free break and withdrawal bleed- a new ring can then be inserted
- May be better tolerated than the COC due to lower systemic oestrogenic side effect
- Ring should not be removed during intercourse- can be removed for a max. 3hrs
- When used properly, it has similar efficacy to the COCP- it has the same metabolic and coagulation effects as other combined hormonal methods
What is the POP?
contains a low dose of norethisterone
must be taken every day without a break and at the same time (±3hrs)
• It makes cervical mucus hostile to sperm- 50% of women inhibit ovulation too
• Failure rates are 1 per 100 woman-years- higher than the combined pill
What are the side effects of the POP?
o Vaginal spotting o Weight gain o Mastalgia o Premenstrual-like symptoms o Functional ovarian cyst can occur
When is the POP used?
• Particularly suitable for older women and those in whom the combined pill is contraindicated (eg. lactating mothers)
there is no risk of thromboembolism and it can be used in almost all situations where the combined pill is contraindicated
