Welcome to brain stuff from how stuff works. Hey, I'm Christian Sager. Welcome to brain stuff. Have you ever thought to yourself, there are a lot of different forms of birth control. I wonder which one works best well? Outside of abstinence. It turns out that inter uterine devices or i u d s are the most effective keeping babies from being made of the time. I u d s are the most popular form of contraception in the world, but in the United States only one point three percent
of women use them as birth control. Now you're probably saying, but Christian, why haven't I heard more about these i u d s if they're so effective. Well, in the nineteen seventies, there was a similar looking device called the Dalkon Shield that gave its users pelvic infections and internal scarring. Some women even became infertile. A class action lawsuit was brought against the A. H. Robbins Company, the makers of the Dalcon, and they got their pants suit off, forcing
them into bankruptcy. The consumer mistrust that the delcn created is still lingering in women's and doctor's minds forty years later. But ladies and gentlemen, calm your fears, because the new I u d s are actually better and safer than their predecessors. So what is this magic baby shield and how does it work well? The i u D is shaped like a T with a string attached that leads into the cervix so women can make sure the device
is still in place. While widely available, you'll still need to go to a medical professional to get one inserted. You can't just go and pick these things up at hobby lobby. First, a doctor will measure the length of your uterus what's also called the uterine sound. If your uterus is too small and i u D might not fit, which is why they're often easier to equip in women who have given birth before. If you've never had a baby,
they may give you a medicine that softens the cervics. First, the fitting is usually done during a woman's menstrual period, when her cervix is slightly open and dilated. Now, I won't lie. You might feel some pain while an iu D is being put in place, but your doctor may give you pain relievers or anesthetic to lower the discomfort. Now, there are two kinds of i u D s. One is coated in copper and can be left in the uterus for up to ten years. The other kind releases
the hormone progesterone and it lasts for five years. So how does copper or progesterone keep you from getting pregnant? Well, doctors today think i u d s prevent fertilization. Either the copper makes the uterus toxic to sperm while slowing and damaging eggs, or the progestin makes a woman's cervical mucus thicker and hostile to sperm. It's like a guard dog for your uterus. It changes the lining and disrupts
the normal environment for an egg. It keeps sperm from reaching your eggs, slows the movement of eggs to your uterus, makes eggs unable to be fertilized, and keeps any fertilized eggs from implanting in the uterus. Iu d s are so active that they can be used as emergency birth control up to five days after unprotected sex. But contrary to popular myth, i u d s do not induce abortions. There's lots of advantages to using an io D as
birth control. First of all, you don't have to worry about contraception every day, and like I said, the effectiveness is very high, with less than one percent of a chance of pregnancy occurring. The hormone releasing version of the io D can even make your periods lighten or stop altogether. After a year, though you might find that bleeding and cramps are worse at first. The copper one will actually make your periods heavier, but some women prefer to have
a hormone free option. Overall, i u D s are discreetly hidden from view, low cost, very low maintenance, and highly effective. But nothing's perfect and there are a few disadvantages to them. Like I mentioned earlier, sometimes they make menstrual cramps and bleeding worse just after insertion. If these
symptoms continue, a physician may have to remove the device. Also, while they're nowhere near as bad as the Dalkon shield, modern i u D s are thought to increase the probability of pelvic infections after the first few months post insertion. If you're one of the less than one percent of i u D users who actually do get pregnant with it, you should see a doctor right away. The device can increase your risk of a miscarriage, infection in the uterus,
and pre term birth of a baby. I u d s also increase the risk of a fertilized egg developing somewhere outside of the uterus, leading to what's known as ectotopic pregnancy. Check out the brain stuff channel on YouTube, and for more on this and thousands of other topics, visit how stuff works dot com.