In this session, Dr Jessica García, Gynaecologist, and Fertility Specialist at Clinica Tambre, Madrid, Spain, discussed the menstrual cycle. Dr García explained all the phases of the cycle.
Dr Jessica García mentions the following situations in which it’s important to understand how the menstrual cycle works:
The menstrual cycle is the monthly hormonal cycle that women have. Its main function is to prepare them for pregnancy, therefore, every month the body changes and prepares for a pregnancy.
The menstrual cycle starts with menstruation, and it can be counted since the first day that a woman has her menstruation or period. Sometimes, women can have a small spotting or bleeding before the actual menstrual cycle starts. Nevertheless, it can be counted when red blood can be seen, not the brown one that women sometimes have before the menstrual cycle.
The typical menstrual cycle is about 28 days long, but it can also last between 21 and 35 days. It’s also normal that every month is slightly different: in one month a woman can have it 28 days, then 29, then maybe 30 and then again 28. This is still counted as a regular menstrual cycle.
The most important thing that happens during the menstrual cycle is that one egg will be developed and released from the ovary. In addition to this, the lining of the uterus will also prepare for a pregnancy in case it happens. This is the biggest function of the menstrual cycle and the most important to know when a woman is trying to conceive or, especially, when undergoing fertility treatment.
According to Dr García:
This is important to understand why we are doing the scans, doing the menstruation, why do I have to inject some medication?, why do we have to do the embryo transfer on a specific date?, or why do I have to use estrogen or progesterone during the cycle?
Dr García mentions and describes the most important female reproductive organs that are essential to know about:
Even though it’s not a female reproductive organ, Dr García talks about the importance of the brain and the structure called the hypothalamus as well as the pituitary gland, or hypophysis, for the menstrual cycle to happen correctly. They are considered very important because they will produce hormones that will control the function of the ovaries as well as the endometrium, and then the ovaries will produce more hormones. Everything is connected.
The menstrual cycle is separated into two cycles: The ovarian cycle and the menstrual cycle. These are very different, but they’re extremely connected and happen at the same time.
During the menstrual cycle, there’s communication between the brain and the ovaries with hormones. Dr García states that her explanation will be based on a cycle of 28 days as this is the average, however, it can be slightly different as it depends on the length of the cycle.
During a 28-day cycle, the main event is the ovulation. The main hormone produced before this is estrogen, which will prepare the egg to be released and also will build the lining of the uterus. After the ovulation, women will have mostly progesterone that will prepare the endometrium for implantation and, if the pregnancy is unsuccessful, this will prepare all the tissue to shed and have the next menstruation to start all over again.
This cycle is really important because in the ovaries, at the start of the cycle, there are some tiny structures called follicles. The follicles contain eggs inside and, even though every month women only ovulate one egg, they will start with lots of follicles in the ovaries. These are very small at the beginning of the cycle and then, to respond to the hormones, they will start producing estrogen. This is the follicular phase of the ovarian cycle.
One of the follicles will be the dominant one because it will get bigger than the rest as it responds better to the hormones produced by the brain, and will be the most prepared one. This follicle will be selected for that month to get ovulated.
After ovulation, explains Dr García, comes the luteal phase. The selected follicle, which has the egg inside, will release it and then remain empty, becoming the corpus luteum. This structure will produce progesterone and the egg will travel around the fallopian tube and, probably, become fertilized.
This cycle happens in response to the hormones.
Between days 1-4:
Between day 4-14:
Day 14: Ovulation
This is considered important because when a woman is undergoing fertility treatment, the medication used before retrieval or the preparation for an embryo transfer during the natural cycle, will be very similar or have the same function as the LH. For this reason, Dr García explains that they use medication that day.
Day 14-28:
After explaining the cycles in detail, Dr Jessica García shares the following overview:
Dr García goes on by saying that:
Every month is what happens is that our body is trying to achieve a pregnancy, over and over again.
Related reading:
One way of checking ovulation is by measuring the LH. When we do the ovulation test, it detects the LH levels because before the ovulation, we will have a peak in this hormone, and this is the one that we can check with the ovulation test. Another method is checking the temperature daily because when we have progesterone, the temperature rises a little, it’s not so accurate, though. We can also check the vaginal mucus, and because it will be changing during the whole cycle, maybe we can notice it because, during ovulation, it can be super flexible, and you can check if you’re ovulating.
The ovulation can be monitored with the levels of progesterone, it’s also one of the best methods to see the ovulation, and I would say the most accurate one is to follow the ovulation or the development of the follicle with scans. It’s impossible to do so when we’re trying at home to have a scan every other day, so I would recommend doing what we can do at home.
The best thing is to do the ovulation test, but I always recommend not to focus that much on the ovulation, but to try to have sexual intercourse around those dates, in the middle of the cycle without trying to check it that much because they will be more relaxed, and I think the pregnancy is more likely to happen when we’re relaxed and not focusing on finding the right time for the ovulation.
This Luteal phase, which is happening just after ovulation, usually lasts 14 days long. When we have a cycle that lasts more than 28 days, usually, the ovulation happens 14 days before we have the next menstruation. That’s why it’s not so easy to know when we don’t have the cycle is not always 28 days, but when we’re trying to conceive, try to do it when we know that it’s going to be 14 days before the next menstruation as well.
Yes, they are. I think they are not the most accurate, as I told you, but doing it at home is helpful. Depending on the kind of periods that you have, we can try to have sexual intercourse like 14 days before when we expect the next period, but I always recommend having it very frequently, maybe between two and three times every week, just to try to have some sperm right there. Having sexual intercourse two or three times every week, we will always have some sperm in the area ready. In case we have the ovulation, it will be waiting for the egg.
Not necessarily. Usually, if you have long menstrual cycles, but you are having them regularly, so if you have them every 40 days, maybe that’s normal for you. It’s a little longer than normal, but not necessarily it’s a cycle without ovulation.
Sometimes you may first check the mucus because it will change during the whole time, then also knowing if you are ovulating or not is by feeling some pain around the ovulation days, a pain that comes and goes. I would recommend doing a progesterone test after day 21, just to check if you’re ovulating or not, that will be a good idea.
Not exactly, in all women. That’s the average, the Luteal phase is always more stable than the first part of the cycle, so we can think about it that it lasts 14 days, not exactly every month and in every woman, but the majority of us will have a more stable Luteal phase for 14 days.
I would recommend staying as healthy as possible, try to eat healthily, try to exercise. Some patients with PCOS, for instance, tend to have longer periods or irregular periods and sometimes the medication can help them to have more regular periods. Some medication, with vitamins, will help them as well, such as Inositol is good to regulate the periods.
When we don’t have PCOS, I will say a healthy lifestyle will be the best option to have a regular period. The period can be affected by the stress as well, or maybe we’re exercising too much, is also not good, so everything done in moderation will help us to have a regular period.
Usually, when you have a 26-day cycle, you’re supposed to have ovulation around day 12. The LH can variate a little, so the ovulation kit is not that accurate as I would like it to be. We cannot trust it 100%, about that period of 26 days, I think your ovulation will occur around day 12.
You could do the ovulation test a little earlier and check what happens because I don’t think you’re going to ovulate on day 14. The luteal phase is usually 14 days long in the majority of the patients, but maybe you are a little different. I would recommend checking other things, such as the mucus, the temperature, also try to understand your body a bit more and try to be more receptive, and maybe you can feel something around the day of the ovulation.
It’s very rare to have a short luteal phase. Some patients have low levels of progesterone, in that case, you could have a little bleeding during the luteal phase. It’s not necessarily weak ovulation, maybe the corpus luteum is not functioning in the right way.
What we can do when we have this kind of short luteal phase is that we can support it with progesterone, after the day of the ovulation, we can start using a very small dose of progesterone to support the luteal phase. There are just a few patients that have this issue, but sometimes it could happen.
Usually, what happens after the egg retrieval is that you will have menstruation earlier than expected. Having it eight days earlier will be normal because of the drop of the hormones.
The cycle will start with this menstruation, so if the length of your menstruation is 28 days, the next cycle will be very close to the normal, and we can count this menstruation even when it was earlier, we can count it as day one. Usually, every cycle after the egg retrieval will be more and more regular until we have a normal cycle back again, so I will say maybe your next menstruation will arrive around 28 days later.
On day 21. We can check the progesterone two days after ovulation, and the progesterone will be rising. The day just to confirm when we’re doing an ovulation test is to check it on day 21, that will be a perfect day because the progesterone will be picking, and we will see the levels are higher. You can check it since day 16 when we’re talking about a 28-day cycle.
That depends on many factors. A lot of pain during menstruation is not normal, so if the pain is super high, I would recommend checking it and maybe doing one scan or just checking it with your doctor. The pain during menstruation occurs because the endometrium is like contracting.
It’s normal to have some more painful periods than the others, and this is by the contractions of the uterus. The hormonal levels could also be implicated in the difference in the pain in two cycles, but it is normal to have a different amount of pain during menstruation.
These are the symptoms caused by the progesterone levels, so we can feel a little bloated, there can be some more humour changes. We can be a little sadder or feeling like crying, or we’re a bit moody. Some patients don’t have any symptoms at all, some others are very sensitive to progesterone. You might feel depressed, you might feel some discomfort, so these are the premenstrual symptoms, and they’re caused by progesterone.
Most of the time, it is more normal to have it the days before the period. Maybe it can occur at the beginning of the period as well because of progesterone.
It could also be because the progesterone levels are dropping, and that could cause a little pain in the breast. It is normal, it’s a part of the hormonal changes during menstruation and the menstrual cycle.
