There are several key points to understand about ovulation:
- Ovulation involves the release of an egg from a follicle in the ovary. Follicles are small sacs that contain eggs.
- The growth and release of an egg from a follicle is influenced by a number of factors, including your overall health and well-being, your environment, and your behaviors.
- To determine when you are ovulating, you can track your menstrual cycle, pay attention to changes in your cervical fluid, take your basal body temperature, or use ovulation tests.
- Some people may experience ovulation bleeding or ovulation pain around the time of ovulation.
What is ovulation?
Ovulation is the process by which an egg is released from the ovary and travels down the fallopian tube. It usually occurs about halfway through the menstrual cycle, or about 13-15 days before the start of the next period. The timing of ovulation can fluctuate from one cycle to the next, and it is possible to have a cycle where ovulation does not occur.
How ovulation can be a powerful tool for your health
It is not uncommon for people to learn about ovulation only when they are trying to become pregnant. However, understanding the ovulation process can provide insight into more than just fertility. Knowing about ovulation can help you understand any hormonal changes that may occur in your body during this time, and can also help you understand how certain factors, such as stress, can affect the timing of ovulation.
According to research, people in the Northern hemisphere tend to ovulate approximately 400 times throughout their lifetimes. This number can be influenced by the use of contraceptives (some of which block ovulation), pregnancy and breastfeeding, and certain behaviors or health conditions that affect reproductive hormones, such as eating disorders or polycystic ovary syndrome (PCOS). In pre-historic times, women would have ovulated much less frequently.
If the conditions are not favorable, ovulation will not occur
The production and release of an egg each cycle is regulated by complex changes in reproductive hormones. Ovulation and the menstrual cycle as a whole can be affected by various factors, including energy levels, nutrition, emotional well-being, and socio-economic factors. Both short-term factors, such as jet lag, seasonal changes, stress, and smoking, and long-term factors, such as polycystic ovary syndrome (PCOS) and thyroid disorders, can impact ovulation.
How does ovulation work?
Ovulation involves the release of an egg from a follicle in the ovary. Follicles are small sacs that contain eggs and take several months to develop before they are ready to release an egg, which is estimated to be around 175 days or around 6 menstrual cycles. At any given time, there are follicles at various stages of development in the ovaries. However, most follicles will not reach the ovulation stage and will die off at different phases of development or pre-development.
At the beginning of each menstrual cycle, a few (around 10) developing follicles are considered candidates for ovulation. By the midpoint of the follicular phase, one of these follicles becomes dominant. When it is ready, the follicle releases its egg, which is then picked up by the fallopian tube. The egg has a window of about 12-24 hours to be fertilized by sperm in the fallopian tube before it begins to degrade. If the egg is fertilized, it travels to the uterus over the next 6-12 days, where it may implant and result in pregnancy.
The release of an egg and the preparation of the uterus for possible implantation are all regulated by changes in reproductive hormones. The first part of the menstrual cycle, during which the follicles develop and the egg is released, is called the follicular phase.
How do your brain and hormones interact with ovulation?
The brain, hormones, and ovaries are all connected and work together to regulate the menstrual cycle and ovulation. The hypothalamic-pituitary-ovarian (HPO) axis is the system that coordinates this process. Follicle-stimulating hormone (FSH) produced by the brain stimulates the growth of follicles in the ovaries, which produce estrogen. When estrogen levels reach a certain threshold, the brain releases a surge of luteinizing hormone (LH), which causes the dominant follicle to release an egg (ovulation). After ovulation, the follicle is transformed into a corpus luteum, which produces progesterone (as well as estrogen). If the egg is not fertilized, the corpus luteum will degrade and hormone levels will drop, resulting in the start of a period. If the egg is fertilized and implants in the uterine lining, the corpus luteum will continue to produce progesterone until the placenta can take over during pregnancy.
Is ovulation a clock?
Changes in the hormonal signals produced by the brain, which can be influenced by various internal and external factors such as stress, diet, and exercise, can affect ovulation and alter the timing and characteristics of your menstrual period. Ovulation may occur earlier or later than usual, or not at all, and your period may also be affected, potentially coming earlier or later than normal and being lighter or heavier in flow.
The 'plastic' phase (Follicular)
The phase of your menstrual cycle when your follicles are developing and preparing to release an egg is called the follicular phase. This phase is known to be "plastic," meaning it can vary in length from cycle to cycle. The length of the luteal phase, which is the phase after ovulation, is typically between 13-15 days. You can estimate when you ovulated by counting backwards from the start of your luteal phase. The length of the follicular phase can vary and is often the cause of changes in the overall length of the menstrual cycle. It is normal for ovulation to be irregular when you first start menstruating, after pregnancy and breastfeeding, and as you approach menopause.
Ovulation: Why does it matter
Not ovulating regularly or not ovulating at all (unless you are taking hormone replacement therapy) can lead to serious health problems. Ovulation helps maintain healthy levels of estrogen and progesterone, which are important hormones that affect many bodily functions including bone density, heart health, metabolism, sleep quality, and mental health. Insufficient levels of these hormones, which can result from anovulation (absence of ovulation) during childbearing years, have been linked to an increased risk of osteoporosis, cardiovascular disease, and certain cancers later in life. Additionally, athletes with menstrual dysfunction, such as a lack of ovulation, have a higher likelihood of experiencing stress fractures.
How do I know if I'm ovulating?
If your menstrual cycle falls within a normal range (a length of 24-38 days with less than 7-9 days of variation from cycle to cycle and a period lasting 2-7 days), it is likely that you are ovulating regularly. On the other hand, if your cycles are consistently longer, shorter, or irregular, it could be a sign of anovulation and you should speak with a healthcare provider. There are several ways to determine if you are ovulating and when it occurs during your cycle, including tracking your cycle length and regularity, using ovulation predictor kits, observing physical signs of fertility such as basal body temperature and cervical fluid, and having a healthcare provider check your hormonal profile through a blood test taken during the mid-luteal phase.
Taking an ovulation test
Ovulation predictor kits can be used at any time, but it is best to test at the same time each day. It is recommended to avoid urinating or drinking large amounts of fluids for at least four hours prior to testing. LH levels tend to rise in the morning between 4-8am. If you test before the LH level has risen, you may get a negative result, but you should still get a positive result the following day. If you are trying to detect the earliest rise of LH or if you are having difficulty getting a positive result, you can try testing at different times of the day to see what works best for your body.