Contraception Flashcards
Why use contraception?
- To prevent unwanted pregnancies
- Worldwide, on a big scale, there is a high maternal mortality rate in developing countries (particularly Africa). The risk of mortality increases with the amount of pregnancies (eventually, something will go wrong).
- Developed nations have always had less pregnancies than the rest of the world. They aren’t having less sex, they are using contraception.
- Highest rates of pregnancy are in Africa, then Latin America, then Asia; no contraception available. Looking at modern day, the results are starting to narrow, but Africa is narrowing the least (this is because of the geopolitics). There are whole countries where there is no contraception provision.
- Contraception is free in this country; from a public health perspective, it is more beneficial to provide contraception (people are more likely to use it).
- Lack of provision is the biggest issue.
What factors would make the perfect contraceptive?
1) 100% Reliable
2) 100% Safe
3) Non User Dependent
4) Unrelated to Coitus = does not ruin the sex
5) Visible to the Woman = i.e. women would have to trust men if they were on a pill. The person who is at risk of getting pregnant will want to be in control.
6) No ongoing Medical Input
7) Completely reversible within 24 hours. Effects of the copper coil are reversed immediately with the next cycle. When coming off the combined pill, the next cycle will begin within 10 days. It is only the progesterone injection (Depo-Provera) that has a significant hangover; takes about 5-6 months to be reversed.
8) No Discomfort
- The perfect contraceptive does not exist; abstinence is the least effective (shown in some countries).
What are the four different scenarios when someone comes in for contraception?
1) Requesting contraception with a method in mind
2) Requesting contraception with no method in mind
3) Returning for repeat contraception with no problems
4) Returning for repeat contraception with problems
What are the two broad types of contraception?
1) Methods which require ongoing action by the individual
- Oral Contraception
- Vaginal contraception
- Barrier Methods
- Fertility awareness = very low chance of getting pregnant on day 2 (1-2%) of the cycle compared to day 14 (30%). There is no day on the cycle that a woman will not conceive, but there are different likelihoods. There are retrospective contraception forms (mostly oral) that women can use too.
- Coitus interruptus
- Oral Emergency contraception
2) Methods which prevent conception by default (are carried out by a clinician).
- IUD = copper-releasing coil
- Progesterone implant/IUS/injection. IUS = progesterone-releasing coil.
Progestogens are a family of hormones that can be used as an implant in the arm or an injectable, e.g. Depo-Provera every 12 weeks.
- Male Sterilisation. If there is a couple requesting sterilisation, the man is the ideal person to get sterilised as it is easier, safer (more accessible) and has a lower failure rate. If there is any indication that a man undergoing sterilisation wants to reverse it later, alternative methods should be explored (low success rate of reversal).
- Female sterilisation
How reliable are different methods of contraception?
- Some are affected by real use and some aren’t.
- 85% of couples who have sex unprotected will achieve pregnancy.
- Diaphragms are another example of perfect use (6%) being a lot more effective than typical use (12%). One of the most common problems is getting them in the right place.
- The major cause of typical use with condoms (18% vs 2%) is not using it or putting it on too late. Human behaviour means we are less likely to do it when it ruins the fun.
- Injectables are effective contraceptives (0.2% vs 6%). The biggest reason for error is patients delaying come back after 12 weeks.
- Progesterone-only pill is very effective (0.3%), but this is only in cases of perfect use. Realistically, people forget to take pills (9%) etc.
- When the method of contraception requires no ongoing input from the user, the real use is the same as perfect use.
- LARCs (long-acting reversible contraceptives) = Progestogen-only injectable (DMPA), Cu-IUD, LNG-IUS, progestogen-only implant. More and more young women now use these LARCs and there has now been a decrease in unwanted pregnancies.
Over 90% of people are still preventing pregnancy, but it could still be better.
What is the eligibility criteria for contraception?
- There are certain conditions that make certain contraceptives more or less suitable (national eligibility criteria).
- Most of the population who use contraception (young, healthy women) can use any kind. The vast majority of women are in the first category (UKMEC 1) whereby they have no/minor pre-existing conditions = Always usable.
- A common condition, like asthma, does not affect the contraception used. This would come under the first category where anything can be used.
- Simple migraines are quite common medical problems that may affect the combined oral contraceptive pill. If the combined oral pill was the best option and what the woman wanted, the clinician may decide that the advantages of using it outweigh the risks of a migraine, so they are broadly usable. This fits into the second category (UKMEC 2) = Broadly usable.
- The third category is the reverse; the risks outweigh the advantages, e.g. a migraine with aura premonition with focal signs. Should try to avoid using it (Counsel/caution)!
- Lastly, the combined oral pill can absolutely not be used for women who have a condition which represents an unacceptable health risk if the contraceptive method is used. If they have had a proven deep vein thrombosis before, they cannot use the combined oral pill because the risks of getting another one are too high and it can kill them = Do not use (UKMEC 4).
- Fortunately, the vast majority of women are in the first category where they have either no conditions or minor ones that do not matter.
What is used in combined oral contraception?
1) Oestrogen EthinylOestradiol - 20,30,35,50 micrograms (synthetic oestrogen)
2) Progestogens
- Older (2nd generation) – Norethisterone (Norethindrone) & Levonorgestrel
- Newer (3rd generation) – Desogestrel, Gestodene & Norgestimate
(Noregestromin)
Latest (derived from Spironolactone) - Drospirenone
How does combined oral contraception act overall?
- One of the most common methods of contraception.
- There is oestrogen and progesterone (as opposed to the progesterone-only pill). When people say “I’m on the pill”, this is usually the one that they’re referring to.
- Oestrogens act in two main areas; the hypothalamus and the pituitary. They enter the bloodstream, reach the hypothalamus and pituitary and the high level causes negative feedback. If administered on its own, it would cause proliferation.
- It is given in pills, a transdermal patch or a vagina ring (absorbed through the vagina instead).
- The combination of oestrogen and progesterone acts in three places; causes negative feedback and switches off the HPO axis to prevent ovulation, it thickens the cervical mucus which prevents sperm entering and the net effect of the oestrogen and progesterone doses is atrophy of the endometrium so it is not secretory. The tubes also do not work very well, so it is harder for the egg and sperm to meet.
- The doses of hormones in the pill are much higher than those found physiologically. This is important; the body assumes this is pregnancy and suppresses the HPO axis (pseudopregnancy).
- There is not total suppression of the HPO axis in everyone. The effects vary between people; when taking oral tablets (more common with pills), the liver will immediately metabolise the drug. Some people are genetically very good at metabolising pills and others are not. When women are very good at breaking pills down, their serum levels are lower than someone who has got much higher levels. Women on the pill will have varying oestrogen and progesterone levels. This does not mean that it is not working. As individual levels vary, there may not be absolute suppression of the ovaries. Many people get follicular activity (can see follicles developing in scans), but they don’t have the proper FSH/LH cycle, so they are still not ovulating (even with follicular activity).
- One of the most common problems with the COCP is spotting and bleeding between (breakthrough bleeding). Bleeding should only occur when the pill has been stopped, but spotting is quite common. This is because women with lower levels (who break the pill down quicker) have less control of their endometrium and tend to get funny bleeding. This can be overcome by increasing their dose to manipulate it.
- They tend not to ovulate, regardless of their serum levels. Progesterone is still around, so it still causes a thin endometrium and thickened cervical mucus. There are multiple levels at which it works, making it a very effective contraceptive. Even if the woman was ovulating, they are very unlikely to get pregnant because of the other factors.
- A common theme of all the progestogen-containing contraceptives is that they work on a number of levels.
How do progestogens act in the COCP?
- Progestogens act on anterior pituitary and hypothalamus, endometrium, fallopian tubes and cervical mucus.
- High progesterone levels cause more negative feedback. Both hormones will do this together.
- Progesterone has the opposite effect on the endometrium to oestrogen; it is anti-mitotic and switches off the oestrogen receptors to cause atrophy.
- It thins the endometrium.
- It is a smooth muscle relaxant. It stops the uterine tubes from functioning and peristalsing.
- High doses of progesterone also thicken the cervical mucus. Mucus plug acts as a barrier to keep sperm out.
What are the advantages of the COCP?
- Rapidly reversible = within 10 days of stopping it, the next normal cycle will begin and the negative feedback is lifted (FSH and LH will be produced again).
- Reliable (if taken properly!)
- Safe
- Unrelated to coitus
- Woman in control
- Halve ca ovary = long term use, as it prevents ovulation, halves risk of ovarian cancer.
- Thins out the endometrium, since it is not proliferating for a long time, also halving the risk of endometrial cancer. Uncontrolled estrogen production causes hyperplasia and then cancer.
- Helps endometriosis, premenstrual syndrome, dysmenorrhoea, menorrhagia. For example, menstrual symptoms, such as painful periods; periods will be much lighter and less painful (thin endometrium). A woman with PMS (premenstrual syndrome), the physical and psychological symptoms building up to a period that ease when bleeding, won’t get this on the pill because the cycle is switched off.
- Women can take the pill continuously (without a week off) to stop periods/pain too. The pill can be taken indefinitely.
What are the disadvantages of the COCP?
1) Cardiovascular risks are some of the most important = both sides of the circulation affected (the venous side and the arterial side). Blood pressure is measured and about 2% of women on the COCP become hypertensive (likely due to the progesterone).
- Young women tend not to get ischemic heart disease (protected by their ovaries), tends to be in 50+. However, the odds slowly rise from the age of 35. With other risk factors at the age of 35, such as smoker, family history, obese, risks associated with cardiovascular disease etc., the combined oral pill will not be given (has a known effect on arteries).
- The major one is on the venous side of the circulation. Oestrogen (naturally in pregnancy or supraphysiological levels like in the pill) acts on the liver, increasing production of coagulation factors. Blood can become hypercoagulable. There will be a small proportion of the population who have other underlying conditions that make them more prone to a thrombosis when their oestrogen levels are increased. Often, these predisposing conditions are familial, so family history is asked. If there is a family history, the patient can be tested for the potential associated risk before being given the pill (if negative).
2) Neoplastic = Recent data has shown that long term pill use is unlikely to increase the risk of breast cancer. The previous data was quite flawed and biased. The risk of cervical cancer is also not increased. Cervical cancer is caused by HPV and women on the pill do not use protection. Therefore, there is an apparent increase in pill users but it has nothing to do with the pill.
- The only cancer that does seem to be more common is users is hepatic cancer, but this is a very rare cancer (especially compared to breast cancer). There is no doubt that oestrogen interferes with sugar metabolism (induces insulin resistance). Patients who are borderline pre-diabetic or diabetic would not use the pill.
3) Gastrointestinal = When objectively measuring weight gain on the combined oral pill, it has never been demonstrated, but it is not as simple as this. Thin people are more likely to contribute to this data, so it is slightly bias, but there is no evidence supporting weight gain. Progesterone increases hunger which is a likely answer.
4) Hepatic = seems to be an increased risk of subsequent gallstones and the need for surgery. This is likely to do with hepatic metabolism again.
5) Dermatological =
- Chloasma = pregnancy glow (oestrogen effect) – flushed face (not harmful)
- The cause of the acne is important. Some of the progesterone in the combined pill, e.g. norethisterone, is quite androgenic (progesterone and testosterone are quite close to each other chemically). There are some women who will get more androgenic effects, like acne, if they go on certain types of pill (still reversible). If the acne is due to polycystic ovaries, using the pill will switch the ovaries off and the acne will get better. It depends on the background of the problem; if a patient with acne and polycystic ovaries needs contraception, the combined pill will be helpful.
6 ) Psychological effects
- Some women get many of these problems, such as mood swings, in their natural cycles and the pill can help improve this by abolishing the cycle. There are other people who are okay until they are put on the pill. Both oestrogen and progesterone have lots of receptors in the brain, so it is not surprising that the differential effect is huge.
- Depression
- Most people don’t have any significant libido effects, but there are some who it will affect differentially (not well understood)
What are the contraindications for taking oestrogen and progesterone?
- There are some patients who cannot have estrogen and progesterone!
1) Previous breast cancer is an absolute no
2) Find the cause of undiagnosed abnormal genital bleeding first before introducing hormones
3) Pregnancy is always a contraindication to everything
4) <3 weeks post partum = risk of thromboembolism. Maximum period of risk is actually postnatally.
5) Breastfeeding = Increased oestrogen levels will switch milk production off
6) Active liver disease as the pill is metabolised by the liver.
7) PH thromboembolism
8) Migraine with aura
9) Thrombophilia
10) Age >35
Relative contraindications: BMI>35;migraine without aura; hypertension; diabetes; hyperprolactinoma;
What drugs induce liver metabolism and reduce hormone levels?
- Griseofulvin
- Barbiturates
- Lamogitrine
- Topiramate
- Carbamazepine
- Oxcarbazepine
- Phenytoin
- Primidone
- Rifampicin
- Modafinil
- Certain antiretrovirals
- Cytochrome P450 complexes = hepatic enzymes that will break drugs down. These drugs, many of them being antiepileptic drugs, activate the cytochrome P450 complexes in the liver. They make the enzymes more active so they break down the oestrogen and progesterone faster, serum levels drop and then there are contraceptive failures.
- Always check any new drug if on COCP !!!!!!
How is the COCP taken?
- Start 1st packet 1st day of a menstrual period (First day of bleeding when all hormone levels are basal)
- Take 21 pills and stop for 7 day break (PFI)
- Restart each new packet on 8th day (same day of the week as started)
- Do not start new packets late
- If late or missed pills in 1st 7 days, condomsIf a woman is later starting her next pack, her cycle will soon begin again (fertility returns); too long without negative feedback. Most unwanted pregnancies on the pill are caused by an extended PFI.
- If missed pills in last 7 days, no PFI
- PFI = Pill-free interval
- A few days into the PFI, there is normally a light bleed for 2 to 3 days. This should be reliable if it is taken properly.
- If the pill affects blood pressure, it is likely to occur in the first 6 months. At minimum, there is an annual BMI and BP check, but it is every 6 months in most places.
What is the combined vaginal contraceptive (adv and disadv)?
- Same as COCP except vaginal delivery (ring) for 21 days. Placed at the top of the vagina with the finger.
- Remove for 7 days
- Releases oestrogen and progesterone. Same drugs but absorbed through the vagina (rather than orally).
- New one put in on day 8
Adv – don’t have to take every day
Disadv - don’t have to take every day!!
What are the progestogen-only methods of contraception?
- Progestogens are a family of compounds that mainly have progesterone-type action. They mainly behave like progesterone, but progesterone itself is not used as it is not biochemically ideal to work with.
1) User-dependent methods = POPs Progestogens (all similar) - Desogestrel (Cerazette)
- Norethisterone
- Ethynodiol diacetate
- Levonorgestrel
- Norgestrel
- With many of the pills, the oestrogen is the same but the progestogen is often different.
- There are pills in all of these, but desogestrel is the only one that is used a decent amount in pills (in Cerazette).
- Injectables are 150 mg of the drug into the buttock (intramuscular). High concentration in the serum; by the time the levels are low, the next injection is taken. Depo Provera (MPA) is taken every 12 weeks, NOT 3 months.
2) Default methods
- Implants, e.g. Nexplanon is a 3 year device that sits under the skin of the arm.
- Hormone releasing IUCD =
Mirena IUS (LNG) (5 years), Jaydess IUS (3 years), Kyleena IUS (4 years
- They all have the same effects; they are all designed to be there in higher than physiological levels to cause negative feedback on the hypothalamus and pituitary, thin the endometrium, reduce the motility in tubes and thicken the cervical mucus. They all work on all of these levels.
How do progestogens act?
- They all have the same effects; they are all designed to be there in higher than physiological levels to cause negative feedback on the hypothalamus and anterior pituitary, thin the endometrium, reduce the motility in tubes and thicken the cervical mucus. They all work on all of these levels.
- Hopefully no ovulation
