In this post i'll talk about something important that we talk way too little about: birth control pills! Just imagine how many girls and women who take these each and every day, and how few of them that knows what they do with our bodies and whats in them. Many are very positive to the pills while others hate them. They are hormones after all that will have effect on not only your egg-production, but also other systems in your body and your brain. For some to the better and for some to the worse! But let's get this started!
As you can see in the picture above women go through different hormonal phases each month. Depending on hormonal levels, the mucosa wall in the uterus will differ in thickness throughout the month. This happens in case the woman would become pregnant and then the fertilised egg can attach easier to the mucosa wall and bury itself there and an embryo could take form. In most cases, you don't get pregnant and the wall becomes so thick the small arteries in the wall can't reach all the way out and the mucosa there literally dies and falls off. As it falls off, small veins will break and you get you start to bleed from the uterus.
There are mainly 4 different and important hormones to keep track on when it comes to menstrual cycles: LH and FSH from the brain, and estradiol (oestrogen) and progesteron from the ovaries.
During the first days of the cycle, FSH - follicle stimulating hormone will be released from a pituitary gland in your brain. This will make your so called follicles in the ovaries start to grow. Only the biggest of them will grow. Here survival of the fittest is definitely applied! The rest of the follicles will stop growing completely. As this chosen follicle matures it will become a tertiary with an ovum in it. This is what will be known as the egg later. The follicle aslo produces estradiol - more and more as it grows, and this will suppress LH (lutenizing hormone) from the pituitary from the brain. The estradiol will also make the secretion from the uterus change - it will become more "watery" and make it easier for sperm to move towards the egg.
The second phase here is called ovulation. The "egg" is about to be set free from the follicle and potentially be able to be fertilised. The estradiol levels peak now and suddenly this makes the pituitary gland start to produce a hell of a lot LH! This is a so called positive feedback mechanism. This makes the soon-to-be egg fully matured. The egg is then released into the oviduct and start its journey through the Fallopian tube. This is normally about 14 days after your period ends.
The fertilisation normally takes place in the ampulla which is the widest part of the Fallopian tube. Or mostly it's not fertilised and will just race its way down and out through your vagina and you will never notice.
At this stage the leftovers from the egg, its old pal the follicle, which is left in the ovaries start to wonder wtf is going on and transforms with help from LH and FSH into a corpus luteum. This yellow ball will produce lots of progesteron. This increases estradiol production. Progesteron and estradiol will then suppress the production of LH and FSH from the pituitary gland. Poor old friend the follicle/corpus luteum did a not so smart thing because now it will die in a process called atrophy since LH and FSH was keeping it alive and growing.
An actual histologic image of a corpus luteum
When the corpus luteum dies and disappears the production of progesteron and oestrogen stops as well, and there comes your period at about day 28-35 into your cycle. Then the process repeats itself.
What do birth control pills do in this hormone chaos then?
Well, normally they contain progesteron which will keep the FSH and LH levels down. This inhibits follicular development and prevents increase of estradiol. The inhibition of follicular development and the absence of LH drop in the cycle will completely inhibit the ovulation. Birth control pills do NOT however make you produce less follicles compared to if you would've not taken pills. We are all born with a pre-set number of follicles in our ovaries and pills won't change that number and therefore neither the start of your menopause.
The hormone levels in your body becomes more stable and many experience improvement of skin with less acne and improvement in temper and also feel better knowing they can't get pregnant for now. Others feel they get depressed and very emotionally unstable from the pills. There's a slight increase of blood plugs from birth control pills, normal risk is about 0,3 % or so and with pills the risk increases to about 0,6 % maximum. It all depends a bit if you have a higher risk genetically or not for blood plugs (trombosis).
There are also different so called generations of birth control pills.
- First generation - no longer available in most countries. They contained higher levels of artificial progestin and oestrogen.
- Second generation - came to use in the 1970s, had a much lower amount of hormones. They contain progestins such as levonorgestrel and norethisterone. Many of these pills are still prescribed today. For instance Loestrin, Microgynon and Logynon.
- Third generation - came about a decade after the second generation came. This group of pills uses progestins such as norgestimate, desogestrel, gestodene and cyproterone acetate. For instance Cilest,Yasmin,Dianette and others.
- Fourth generation -The most recent type of combined oral contraceptives contain the progestin called drospirenone. This transform into a natural form av oestrogen in the body. For instance Qlaira and Zoely.
So hope this helped you a bit in this jungle of hormones and pills!