Transcript for:
Hormonal Contraception

hello and welcome to the presentation on hormonal contraception all exam questions on this content will be derived from the objectives listed here to understand how hormonal contraceptives work we must first understand the normal menstrual cycle we'll start at the bottom of this diagram which depicts the thickness of the inner lining of the uterus also known as the endometrium day zero is when a woman's period begins or when she begins bleeding this is a result of the fluffing of the endometrial lining as you can see in this picture the lining of the endometrium begins to thin at day zero the lining continues to thin until about day five in the menstrual cycle when it begins to thicken again and bleeding slows this is in preparation for the implantation of a fertilized egg now looking at the top diagram of the ovary the egg begins the ovulation cycle small and immature it matures until about day 14 in the cycle when it is released which is called ovulation now looking at the middle picture we know that the ovarian hormones play a large role in both the ovarian and the menstrual cycle there is a spike in estrogen prior to ovulation that tells the body that the uterus is ready to host a fertilized egg this causes the ovaries to release an egg which travels through the fallopian tubes and into the uterus after this the estrogen level decreases and progesterone levels increase progesterone is important for maintaining pregnancy in this case the woman is not pregnant so the progesterone decreases and causes the endometrium to slough again the pregnancy rates for women who have intercourse without using a prevention method are actually quite high 25 percent of women become pregnant after one month and 85 percent of women become pregnant after one year there are a number of different methods that can be used to prevent pregnancy both hormonal chemical and physical barriers this chart shows some of the available methods with the more effective methods at the top and the less effective methods at the bottom this presentation will focus on hormonal contraceptives now that we have a basic understanding of the normal menstrual cycle we can start discussing hormonal contraceptives the most common are oral contraceptives also known as the pill the pill is taken daily the other options listed on the slide are changed injected or inserted less frequently from once weekly to every five years the patch has changed once weekly but is not used as often as there have been issues with the patches falling off and there has been a higher incidence of blood clots in this lecture we will cover the other options on the slide oral contraceptives depo-provera injection nuvaring vaginal ring implanon implant iuds as well as emergency contraceptives hormonal contraceptives can contain a single hormone or a combination of two hormones single hormone contraceptives contain only progestin there are no hormonal contraceptives that contain only estrogen combined contraception contains both progestin and estrogen using the two hormones together is more effective but estrogen can cause side effects and is not appropriate in some women in these women progestin only methods are preferred for example we use progestin only pills while women are breastfeeding using combined contraceptives results in higher than normal levels of estrogen and progestin in the body this causes the body to turn off the chemicals that trigger hormone release resulting in the prevention of ovulation or the release of an egg if an egg is not released from the ovary conception cannot occur combined contraceptives also work by thickening the cervical mucus this makes it more difficult for the sperm to reach the egg in addition the pills make it difficult for the egg to attach to the uterine lining oral contraceptives differ by the amount of hormones they contain the progestin only which we mentioned previously only contain a single type of hormone they are slightly less effective than the combination hormonal contraceptives as you see here however among the different types of combination products there is no difference in efficacy instead they differ by the amount of each hormone in each pill based on where the woman is within her cycle with monophasic pills all 21 days of the active pills have the same amount of hormones biphasic has two phases of hormones in each month these products have really fallen out of favor and are not used very much anymore finally triphasic pills mimic the body's natural release of hormones more closely having three different levels of hormones in the active pills an example of triphasic pills is ortho tricyclin as mentioned previously there is no benefit in terms of preventing conception when considering one type of phase over the others but some phases may help to alleviate symptoms of menstruation such as swollen breasts and migraines more than the other types like all medications oral contraceptives can cause side effects these side effects can be broken down into the estrogen related side effects and the progestin related side effects too much estrogen can cause headache or nausea whereas too little estrogen can cause mid-cycle breakthrough bleeding this bleeding occurs in the middle of a woman's cycle and is not associated with menstruation too much progestin can cause fatigue acne and weight gain while too little progestin can cause late-cycle breakthrough bleeding the serious side effects that we worry most about with oral contraceptives are related to estrogen increased levels of estrogen can lead to a stroke heart attack or blood clots in the legs or lungs for this reason we advise many women who are at an increased risk of blood clots not to use estrogen-containing oral contraceptives we'll discuss specific examples of these women shortly all oral contraceptives are taken similarly they contain active pills and placebo pills the active pills contain hormones these pills are taken daily for 21 days for most oral contraceptives some products known as extended cycle products have the active pill taken continuously for three to six months during that time a woman would not have her period placebo pills follow the active pills when a woman is taking the placebo pills menstruation will occur placebo pills are really used as a reminder to take the pills every day by continuing the routine rather than not taking a pill for the entire week there are two ways to start oral contraceptives the first is to simply take the first pill and in the pack on the first day of menstruation or the first day of the woman's cycle the second way is to start the first sunday after menstruation occurs the benefit of the sunday start is that women's menstruation will occur during the week and a woman could have period-free weekends there are some contraindications to oral contraceptives this means that women with these conditions or characteristics should not use hormonal birth control the first is breast cancer this is because some breast cancers actually feed off estrogen and are hormone dependent taking oral contraceptives containing estrogen can make these types of breast cancer worse combined oral contraceptives are also contraindicated in women who smoke and are over the age of 35. this is because smoking increases the risk of blood clots as does increased age the combination of estrogen smoking and age greatly increases the risk of the clot these clots can occur anywhere in the body and may cause heart attacks or strokes oral contraceptives should not be used in pregnancy in order to avoid necessary hormonal changes for a successful pregnancy estrogen can interfere with milk production so estrogen-containing pills should not be used while breastfeeding as mentioned previously women may use progestin only pills or other progestin products while breastfeeding oral contraceptive pills have other uses besides contraception one is the treatment of acne we talked earlier that too much progestin can cause acne some oral contraceptives contain a specific progestin that actually makes acne better another use is endometriosis endometriosis is an overgrowth of the endometrium or the lining of the uterus often this occurs outside of the uterus and can cause a lot of inflammation and pain oral contraceptives decreases overgrowth thereby treating the pain and inflammation associated with endometriosis oral contraceptives can also be used to treat painful menstruation or dysmenorrhea using birth control decreases the pain of menstruation for many women some women have very irregular periods with periods either occurring more or less frequently than every 28 days the hormones and oral contraceptives can help regulate the period to occur every 28 days now we'll talk about nuvaring nuvaring is a combination hormonal contraceptive that comes in the form of a flexible transparent vaginal ring this ring is inserted into the vagina for three weeks at the beginning of the fourth week of the month the woman removes the ring and then she has her period a new ring is used every month it works similarly to combination oral contraceptives by preventing ovulation thickening the cervical mucus and making implantation of a fertilized egg on the uterine lining more difficult side effects are also similar to birth control pills but women may also experience vaginal infections changes in vaginal discharge and vaginal irritation depo provera is a longer term progestin only contraceptive it is injected into the muscle of the arm or buttocks every three months the medication forms a deposit of drug in the muscle and that deposit slowly releases a steady stream of progestin into the bloodstream side effects with this medication are common and usually include weight gain and acne that should make sense since both of these symptoms are associated with excess progestin as we discussed earlier depo provera also causes amenorrhea which is when a woman stops menstruating altogether this can be a big benefit for women who choose this method of contraception a more recent discovery is that long-term use greater than two years can cause a decrease in bone density putting the woman at risk of fracture thankfully when the drug is stopped bone density returns to normal however it is recommended that women who use depoprovera for more than two years have their bone density checked yearly implanon is another progestin-only long-term contraceptive it is a matchstick-sized flexible rod that is implanted under the skin of the upper arm and left in place for up to three years the implant releases the constant stream of progestin into the bloodstream so similarly to depo-provera however since the progestin is different in implanon than in depo-provera implanon does not cause a loss of bone density it can cause other progesterone-related side effects though such as weight gain acne depression and changes in the menstrual cycle there are a number of different intrauterine devices or iuds on the market today there are both hormonal and non-hormonal iuds like paragard which is a copper iud for the purpose of this course we will only cover the hormonal iuds as they are most commonly used mirena is likely the one that you have heard of but skyla loletta and kyleena are also approved iuds on the market these products only differ in size the amount of hormone and the length of use they are all progestin only devices containing the hormone levonogestral iuds are plastic t-shaped devices inserted into the uterus as seen in the picture there are short soft threads that are left out of the cervix so the device can be removed later on like the implanon implant hormonal iuds work by releasing a constant amount of progestin in the body to prevent pregnancy each of these products mentioned differs by their length of use but is generally anywhere from a maximum of three to five years however the iud can be safely removed before then the most common side effect is cramping upon insertion as well as changes in bleeding on your period some women may notice an increase in bleeding right away but this will generally slow over time often women with iuds notice very light very few or even a lack of periods completely over time women with hormonal iuds are also more prone to developing ovarian cysts however many women don't notice them and they go they safely go away over time finally while rare the insert does put you at a greater risk of developing an infection known as pelvic inflammatory disease there are two kinds of emergency contraception available one contains the same progesterone hormone we just discussed levone or gestural and is known as plan b or plan b one step in order to be effective it must be taken within 72 hours of unprotected intercourse but the sooner it is taken the better plan b used to be prescription but is now available to anyone of any age over the counter another product used much less commonly is ella ella contains a medication that binds the progesterone receptor in the body meaning that it acts like progesterone but isn't it can be taken up to five days after unprotective intercourse however it is prescription only and approved only for women greater than 18 years old studies have also shown that ella may be less effective in women with a bmi greater than 30. remember that a bmi between 25 and 30 is classified as overweight and a bmi of greater than 30 is classified as obese it is also important to note that emergency contraceptives should only be used in cases of emergency it is not appropriate to use emergency contraceptives as a regular means of preventing pregnancy once a woman stops using contraceptives how soon can she get pregnant well it depends on the contraceptive she was using some like nuvaring implanon and plan b ella lose effectiveness immediately after they are stopped or removed others like progesterone only pills can lose effectiveness even if a single dose is missed by more than three hours on the other hand return to fertility can be delayed by up to one year for women stopping depo provera the most common time frame for women on combination oral contraceptives is one to six months with the majority becoming fertile within three months after stopping the medication