So, you don’t want to get pregnant: the science behind birth control

My body, my birth control

Understanding how birth control works is virtually impossible without a discussion of ovulation. “Well. Duh. That’s a no-brainer. I was one of the few people who had access to a comprehensive sex education while I grew up, and that makes total sense to me,” you might say. Or you might say, “society has impeded me from obtaining an adequate sex education and therefore I have no friggin clue what ovulation is.” Don’t worry. These are all legitimate things to think. Hopefully, no matter your level of knowledge, you will find useful information on this page whether that’s an introduction to something you’ve never studied before, or a review of something you’re completely familiar with. Knowledge is power. So, stick with me and we will learn what ovulation is, and how certain types of birth control stop it from happening.

Ovulation

Ovulation occurs when an egg is expelled from an ovary and enters into the fallopian tubes. In your brain, there’s a tiny region called the hypothalamus. This little guy is located just above the brainstem, and though it be but little it is fierce. Before ovulation begins, the hypothalamus releases a hormone called gonadotropin releasing hormone. Fancy science people call it GnRH for short. This hormone travels to the anterior pituitary gland (which is just below the hypothalamus) wherein two more hormones are released into a woman’s bloodstream. These hormones are called follicle stimulating hormone (FSH for short) and luteinizing hormone (LH for short). I like to imagine these two hormones as little text messages the brain sends to a follicle (which surrounds the egg) in the ovary. These “text messages” tell the most mature follicle in the ovary to start growing more rapidly. As both the follicle and the egg it surrounds begins to grow, the follicle sends text messages back to the brain in the form of the hormones estrogen and progesterone. The back-and-forth “text messaging” between the follicle and the brain results in a large increase in the amount of estrogen excreted by the follicle. These large levels of estrogen peak right as the follicle begins to increase its secretion of the hormone progesterone. This increase in progesterone signals the pituitary gland to pump out a ton of LH. Imagine this as a stream of texts that you’ve received on your phone from your mom who is telling you that you need to get home. NOW. All I know is that if MY mom sent me text after text, telling me to come home, I would follow her instructions to the T. So, the surge in LH means the egg has just been bombarded with a shit ton of text messages from its mom telling it to ovulate. NOW. The egg is then expelled from the ovary, and travels into the fallopian tube. Thus, ovulation has occurred!!!

The science of contraception

Now to the meat of the problem. There are two different types of birth control that exist: hormonal methods and barrier methods. Barrier methods (such as your typical and well-known male condom, lesser known female condom, cervical caps, cervical sponges, spermicide, etc.) create a physical obstruction that effectively blocks sperm from reaching an egg. These methods are safe, affordable, and some have the added benefit of protecting against STIs. However, they are not the most effective means of preventing pregnancy because there is a high instance of user error. The more effective forms of contraception are definitely hormonal ones! And among those, the IUDs, also known as intrauterine devices, and arm implants result in the fewest pregnancies. Less than 1% of users become pregnant within a year of using them.

So, how do these hormonal methods of birth control work exactly? Simply put, hormonal contraception prevents ovulation from happening. No egg leaves the ovary. None. As long as you are using your contraception correctly, your egg will not be released from your ovary and will never meet up with any sperm hanging out in your uterus.

Remember LH and FSH? The “text messages” that the brain sends to the egg in the ovary that tells it to start growing, and eventually causes it to explode out from the ovary? Well, hormonal contraception suppresses large amounts of LH and FSH from ever being sent in the first place. Hormonal contraception is made up of estrogens or progestin, a synthetic form of progesterone. The low levels of estrogen (found in combined oral contraceptive pills, the shot, the patch, and the Nuva ring) regulate the amount of LH and FSH that are released into the person’s body. Progestin-only hormonal methods (such as some IUDs, the implant, and progestin-only pills) prevent a surge in the LH hormone by inhibiting an increase in the body’s progesterone.

Okay, so now what?

To wrap things up, here is what you should absolutely, 100% takeaway from the nonsense described above:

–Hormonal contraception prevents ovulation from ever happening. This means my eggs stay nice and comfy inside my ovaries.

-Barrier methods of contraception physically block sperm from meeting with an egg. They do not prevent ovulation.

-Choose a method of birth control that is right for your body and your behavior. Be smart about it. You’ve got this.

If you are shopping for birth control, and want to have a complete list of available contraception with explanations that discuss the benefits and drawbacks of each method, check out the website bedsider.org. Seriously. I cannot plug this website enough. Just go to it. It’s amazing.

originally posted on https://comprehensivecontraception.wordpress.com/science-and-shit/