 Modern medicine is a wonderful thing and allows us to take more control over our bodies. From our video in the menstrual cycle, you should know all about how estrogen, progesterone, luteinizing hormone and follicle stimulating hormones work in the menstrual cycle. In this video, we are going to look at how these hormones can be used in contraception and compare them to non-hormonal methods. We are also going to look at the use of hormones in treating infertility. Today we are lucky enough to live in a world where we can control when we have children. Women can have a career and do not have to worry about getting pregnant at the wrong time. And this is all because of our understanding of the hormones involved in the menstrual cycle. Because female fertility is controlled by hormones, this means that knowledge of these hormones can be used to increase or decrease the chances of fertilization and pregnancy. It is actually pretty simple. FSH causes the egg to mature in the ovary. So if we can stop the production of FSH happening, then we can prevent pregnancy happening. And we already know that estrogen prevents the production of FSH. So contraceptive pools just need to contain estrogen. Progesterone also can act as a contraceptive. It makes the mucus in the uterus very thick and so the sperm cannot get through to the egg to fertilize it. Pills are either estrogen only, combined estrogen and progesterone, or nowadays there is a mini pool which is progesterone only. Each contraceptive pool contained much higher amounts of estrogen. This caused quite significant side effects such as weight gain, mood and blood pressure. More modern pools contain much less estrogen and some are even just progesterone. Progesterone is a lot more gentle on the body. Estrogen pools make the body think that it is in a permanent state of pregnancy. Oral contraceptives are great in many ways. They give people the freedom to choose when to have a child and when not to have children. But as mentioned above, even the more modern versions can cause side effects in people. There is also an increased risk of developing blood clots. So they are not perfect. And so people do seek out other methods of contraception instead. Interuterine devices, IUDs or coils are another contraceptive option. They must be fitted by a doctor and have spermicidal properties and prevent implantation. Or they are also contraceptive implants which work by releasing progesterone into the body and last for 3 years. Whereas the contraceptive injections also make use of progesterone, but they only last for between 8 and 13 weeks. Non-hormonal methods of contraception include condoms and other barrier methods, which stop the sperm from reaching the ovum. How effective these methods of contraception are depends on whether you use it correctly. The IUDs and implants are great because they do not have human error. You cannot forget to take it or put it on. If taken correctly, the contraceptive pull is over 99% effective. But you need to take it at a similar time each day and remember to take it daily. Other than condoms and barrier methods, all forms of contraceptives come with differing side effects and goals should consider the different options when deciding which one suits them best. So that is how we use our knowledge of hormones to prevent pregnancy. But what about helping women conceive? Some women don't produce enough FSH to allow their eggs to mature and so have difficulty becoming pregnant. Fertility drugs contain FSH and also LH, which stimulate the egg to mature in the ovary. Remember that LH causes the mature egg to be released from the ovary. Because fertility drugs contain FSH and LH, this can cause multiple eggs to be released and so increases the chance of multiple conceptions, twins or even triplets. Fertility treatments do increase a woman's chances of becoming pregnant, but it's not 100% assured and there can be other factors to consider. So from this video you should know that we can use our knowledge of estrogen and progesterone to act as contraceptive pools and we can make use of FSH and LH in fertility treatments.