{"id":1404,"date":"2020-02-10T15:58:54","date_gmt":"2020-02-10T15:58:54","guid":{"rendered":"https:\/\/staging.theduff.co.uk\/?p=1404"},"modified":"2020-10-01T15:43:49","modified_gmt":"2020-10-01T15:43:49","slug":"menstrual-cycle-explained","status":"publish","type":"post","link":"https:\/\/theduff.co.uk\/menstrual-cycle-explained\/","title":{"rendered":"The menstrual cycle<\/strong> explained"},"content":{"rendered":"\n

YOU KNOW WHAT I FIND WEIRD?<\/strong> The fact that most of us wouldn\u2019t be able to explain how menstruation works \u2013 let alone namecheck all the hormones involved \u2013 despite the fact that it happens to us in a very visual, physical and emotional way every single month. <\/em><\/p>\n\n\n\n

Until I read up on it, all I knew was that an egg finds its way into the fallopian tube somehow, and if it doesn\u2019t mate up with some sperm coming from the other direction, the uterus lining breaks down and that\u2019s known as a period. Did I manage to pass GCSE Biology with that <\/em>level of understanding? Sheesh. <\/p>\n\n\n\n

Obviously, there\u2019s a lot more to menstruation than that \u2013 and having a basic understanding of the process will come in particularly helpful if you\u2019re undergoing fertility treatment. Why? Because if you know what happens during a \u201cnormal\u201d cycle, you\u2019ll be far better able to grasp what they\u2019re trying to achieve (and why) when you read other articles on this site about IVF. <\/p>\n\n\n\n

The following explanation isn\u2019t a comprehensive, blow-by-blow account of everything that happens: that would use up far too many pages of the internet. Instead, it\u2019s a nutshellised version of the need-to-know stuff. <\/p>\n\n\n\n

Enjoy! <\/p>\n\n\n\n

Follicles! Growing! <\/strong><\/h2>\n\n\n\n

1: Inside your ovaries are hundreds of thousands of follicles \u2013 and most of those follicles (about 90% of them) contain something called an oocyte, which is an immature egg cell. (It\u2019s pronounced \u201coh-iss-site\u201d but I prefer \u201cOOOOH!-site\u201d.) The other follicles are empty, useless, poor excuses for follicles \u2013 but at least they\u2019re in the minority.<\/p>\n\n\n\n

\"Follicle<\/figure><\/div>\n\n\n\n

2: Many follicles<\/a> begin to develop\/grow at the same time \u2013 and the oocytes inside them begin to develop too. This is thanks to a hormone called \u201cfollicle-stimulating hormone\u201d (FSH), which is released by the pituitary gland. (In case you\u2019re wondering, the pituitary gland can be found behind the bridge of your nose.) <\/p>\n\n\n\n

How does the pituitary gland know what to do? Well, the hypothalamus in your brain produces a hormone called \u201cgonadotrophin-releasing hormone\u201d (GnRh). This hormone travels to the pituitary gland and tells it to release FSH. If you\u2019re wondering how the hypothalamus <\/em>knows what to do\u2026 just think of it as the all-knowing, all-powerful ruler of your brain. <\/p>\n\n\n\n

3: While the follicles are developing, the cells around the eggs inside those follicles will produce another hormone, oestradiol (a type of oestrogen), which causes the lining of the uterus to thicken and prepare for an exciting new visitor: a fertilised egg.<\/p>\n\n\n\n

\"Chart<\/figure><\/div>\n\n\n\n

One follicle takes the lead<\/strong><\/h2>\n\n\n\n

4: Even though lots of follicles started to develop at the same time, there\u2019s one standout, chest-thumping MVP of a follicle that grows faster than all the others \u2013 and it\u2019s known as the \u201cdominant follicle\u201d. The cells inside that follicle will produce a buttload more oestradiol, which in turn sends a signal to decrease the amount of FSH being produced. The decrease in FSH has the effect of quieting all the other follicles, leaving only that one dominant follicle to continue growing. <\/p>\n\n\n\n

5: Once that follicle reaches about 15\u201324mm in diameter, the oocyte inside it is pretty much ready to be fertilised. Only one ovary will produce the \u201cdominant follicle\u201d each time, and (pub quiz trivia time), the right ovary is more likely to be the winner<\/a>.<\/p>\n\n\n\n

\"\"<\/figure><\/div>\n\n\n\n

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