Did you know there are some methods of birth control that last up to five years! Or, if that is too long, some that last three months at a time? Learn about these two options in this lesson on contraceptive injections and IUDs.
So, we all know about the birds and the bees; I'm sure many of you had that somewhat awkward talk with your parents or in health class. And, hopefully, that talk included something about birth control. Or, perhaps you've been to your doctor lately, and they've asked you, 'what methods of birth control do you use?' Or, maybe they used a less familiar term, contraceptives.
See, what many commonly call birth control, often referring to things like condoms and birth control pills, is also called contraception or contraceptive methods. Contraceptives are methods that can be used to manage fertility or prevent conception (or fertilization), the fusion of the female's egg with the male's sperm. See, the prefix 'contra-' means against or opposite, so 'contra'ception is against conception, making its goal to prevent the sperm from meeting the egg, thus preventing conception!
The doctor may have also explained there are different types of contraceptives and that some of these use hormones. These are called hormonal forms of contraception. They accomplish the goal of contraception by altering the levels of the female hormones estrogen and progesterone to prevent fertilization and pregnancy. These can come in the forms of pills, patches saturated with the hormones, implants and other methods that allow the hormones to enter the body.
But, for some women, having to remember to take a pill every day, or change a skin patch once a week, or even getting an implant put under the skin is too much to worry about. That's where the option of getting a hormone injection may come in handy! It's quick, convenient and, once done, you don't have to think about it for another 12 weeks.
The most common hormone injection used for contraception in the United States is called Depo-Provera. It's a progesterone-based injection, given in the arm or buttocks, that provides contraception for 12 weeks at a time. You can think of it like it's depositing progesterone into the body. The progesterone enters the bloodstream where one of its jobs is to fool the body into thinking it's already pregnant.
When you're pregnant, the ovaries start producing higher levels of natural progesterone to let the brain and the rest of the reproductive system know that 'a baby is on the way, so halt the production of more eggs and get ready!' By injecting the body with man-made (or synthetic) progesterone, we're trying to imitate or mimic this process. Our synthetic progesterone looks similar to natural progesterone, kind of like it's wearing a mask to help fool the body into thinking it's the real thing.
So, how exactly does it work? Well, the progesterone-only forms of contraceptives use a few different methods to achieve contraception:
- They prevent ovulation, or the release of a mature egg from the female's ovary.
- Thicken the mucus in the cervix, the area circled below, to prevent sperm from passing through and into the uterus. This helps prevent fertilization because the sperm cannot reach the egg.
- They thin the lining of the uterus, making it more difficult for a fertilized egg to attach to it.
The cervix is circled in yellow.
And, of course, like all hormonal forms of birth control, the Depo injections have both advantages and disadvantages. Let's start with the good! Advantages:
- First, as you've already learned, it's convenient - one injection every three months!
- It also doesn't interfere with sex or daily activities.
- It has less side effects than estrogen/progesterone combination pills.
- It can be used by nursing mothers.
- It even has some health benefits, including a reduction in pain and bleeding for those suffering from certain conditions of the reproductive tract, such as endometriosis or uterine fibroids.
But, of course, these come alongside some potential disadvantages. Depo injections, like other forms of hormonal contraception, do not provide protection against STDs. In addition to many common side-effects of hormonal contraceptives, such as headaches, nausea and breast tenderness, Depo-Provera can also cause:
- Slight weight gain
- Irregular menstrual bleeding or spotting
- Possible bone loss (however, this is reversed once injections are stopped)
- An increased risk of blood clots and cardiovascular disease, especially in women who smoke or have a history of cardiovascular disease or circulatory problems
Women on Depo injections also take longer to return to normal fertility than other methods of contraception - around 10-12 months after the injections have stopped. And, of course, our patient just has to make sure she schedules an appointment for her next injection every 12-13 weeks to keep the progesterone levels in her body consistent. If this schedule is followed, Depo-Provera injections are 99.7% effective in preventing pregnancy; however, the average failure rate during the first year is closer to three percent.
But, maybe the thought of a needle every few months is too much for our patient, or maybe she wants something she can forget about for a few years - then an intrauterine device (IUD) might be the right choice. This small, plastic, T-shaped device is placed inside the uterus just like the name 'intra-uterine' suggests, and is left there for up to five or ten years. It has small strings that hang outside the cervix that allow the doctor to check the IUD and help in its removal from the uterus. But don't worry, while it may sound a little uncomfortable, most women only experience slight discomfort for the first few days and then don't even notice it's there.
Currently, there are two types of IUDs commonly recommended by doctors: one that uses hormones and another that uses the metal copper. The levonorgestrel (or Mirena) IUD slowly releases small amounts of synthetic progesterone that work in the same ways that the Depo-Provera injections work - by introducing a synthetic progesterone to the body to help fool it into thinking it's pregnant. This synthetic progesterone does this by preventing ovulation. It also prevents fertilization by impeding sperm passage and prevents pregnancy by preventing implantation of the egg in the uterus.
The other type of IUD can stay in place for up to ten years at a time! This is the copper-based IUD called ParaGard. This type of IUD does not contain any hormones; instead, it uses the metal copper to cause biochemical changes in the uterus that interfere with the movements of the sperm and the eggs, and prevent implantation of the egg in the uterus. You see, to sperm, copper is like a toxin. It causes the female's reproductive tract to make a fluid that kills the sperm before they can make it to the egg - like the sperm version of kryptonite! And, of course, both come with some advantages and disadvantages. Both IUDs:
- Offer long-term contraception that is both reliable and convenient. The average failure rate of IUDs is around .8% for ParaGard and 0.2% for Mirena during the first year, but with long-term use, IUDs are more than 20 times more effective than other forms of birth control.
- Doesn't interfere with sex or daily activities.
- Can be used by almost all women, including nursing mothers who can't use any form of contraceptive that includes the hormone estrogen.
- Some research suggests they can reduce the risk of uterine cancer.
The hormonal IUD, Mirena, also reduces menstrual cramps and bleeding, but it comes with more potential side-effects, including headaches, nausea, depression and breast tenderness. Serious complications, however, are rare. But, when they do occur they can include:
- Migration of the IUD into the uterine wall. Therefore, the placement of the IUD should be checked by your doctor periodically.
- Movement of the IUD out of the uterus occurs in about five percent of patients.
- Pelvic inflammatory disease, or infection and inflammation of the uterus and uterine tubes (which are all located in the pelvic area). This has been shown to occur in around one percent of patients.
- In very rare cases, ectopic pregnancy can occur; this is when the fertilized egg attaches outside the uterus.
Importantly, younger women are more susceptible to some side-effects, including risk of infection, which, if left untreated, may result in a reduction in fertility. Therefore, most doctors suggest that women who are planning on pregnancy in the near future should not use IUDs as their contraceptive of choice.
For younger women, there are still many options for birth control, but his lesson just focused on two of the many options out there. The Depo-Provera injection is a progesterone-only injection, administered every 12 weeks, while the intrauterine device (IUD) is a small, T-shaped plastic device inserted into the uterus that provides contraception for up to five years.
Both the Depo-Provera shot and the IUD can be considered hormonal forms of contraception. This means that they alter the levels of the female hormones to prevent fertilization and pregnancy. Specifically, both the Depo injection and the Mirena IUD use a synthetic form of the female hormone progesterone to:
- Prevent ovulation
- Impede sperm passage
- Prevent implantation of the egg in the uterus
But, there's another type of IUD called ParaGard. This is a copper-based IUD that alters the chemistry of the uterus to kill sperm and prevent implantation and can be left in place for up to ten years. And, of course, both of these contraceptives have both advantages and disadvantages to their use, and both need a doctor to either administer injections or insert and remove the IUD.
After you have finished with this lesson, you'll be able to:
- Define contraception
- Describe how the Depo-Provera shot and the two types of IUDs prevent pregnancy
- Explain the advantages and disadvantages of Depo-Provera and IUDs
- Summarize the effectiveness of these two types of contraceptives