Introduction

To many, ovulation remains a confusing and mysterious topic, not quite understanding its purpose and importance. Understanding ovulation and how it works is not only crucial for getting pregnant, but also for your general health. In this short article, we are going to dive into the science of ovulation, understand the key hormones that play a part in it, and how it is a part of how your body prepares for conception. 

Understanding the fundamentals

What is ovulation?

The simple definition of ovulation is the process of an egg being released from one of the ovaries into the fallopian tubes. ¹

Why does ovulation happen?

In people assigned female at birth (AFAB) of reproductive/childbearing age (from 15 to 49 years old), ovulation is the body’s physiological process to create offspring.

How often does ovulation happen?

Ovulation typically happens once per menstrual cycle. It is a key part of the menstrual cycle, and for it to happen, there is a series of hormonal processes that take place to prepare the body to release a mature egg.¹

The menstrual cycle

On average, a menstrual cycle lasts approximately 28 days but can range between 21 to 35 days. It consists of 4 stages: 

• Menstrual phase (days 1-8): the endometrial lining (uterine wall) sheds, in case pregnancy did not occur, and you get your period. The number of days can vary between each person; however, within a range
• Follicular phase (days 1-13): During this stage, some of the follicles in the ovaries are “selected” to grow. Towards the end of this stage, there is one dominant follicle, bigger and more mature than the rest
• Ovulation phase (around Day 14): the dominant follicle ruptures, and the mature egg is released
• Luteal phase (days 15-28): The dominant follicle turns into the corpus luteum

If the egg is not fertilised, the menstrual cycle resumes again.²

Main hormones during ovulation 

Hormones are the body’s message carriers. They transfer chemical information that controls many body functions. During ovulation, there are 4 main hormones. The interplay of these 4 main hormones is important to orchestrate the start and end of ovulation during the menstrual cycle. ¹

FSH (follicle-stimulating hormone)

FSH (Follicle-Stimulating Hormone) stimulates the growth of ovarian follicles, which contain the developing oocytes (eggs), which grow alongside the follicles.

Estrogen 

Estrogen is a key player in the induction of ovulation. When estrogen levels rise to a certain level, LH (Luteinizing Hormone) is induced, signalling the onset of ovulation.

LH (Luteinizing hormone)

LH surge is what triggers ovulation. LH has some other functions too, including preparing the uterus for a potential implantation of the fertilised egg and progesterone stimulation.

Progesterone

When ovulation happens, the follicle bursts and the egg is released from the ovary to the fallopian tube, then to the uterus. The residual follicle secretes progesterone to make the uterus a welcoming environment for implantation and support a potential pregnancy. If a fertilised egg successfully attaches, the corpus luteum produces progesterone during the initial stages of pregnancy until the placenta forms and assumes responsibility for progesterone production for the duration of the pregnancy.

The fertile window

Throughout a typical menstrual cycle for women, there are 6 days when sexual intercourse may lead to pregnancy. This is called the "fertile window" and includes the five days preceding ovulation and the day of ovulation. The timing of both ovulation and the six fertile days can differ from one cycle to another.

This is because sperm can survive in the female reproductive tract for up to 5 days. On the other hand, the ovulated egg survives for up to 24 hours. If sperm is present in the body within the days of the fertile window, there are high chances that it can fertilise the egg.⁴

Signs your body might be ovulating

Sometimes your period might be delayed, or it might last longer/shorter than usual, affecting the other phases of your cycle. In such cases, or in case your menstrual cycle is generally irregular, tracking your ovulation can be difficult, as you cannot rely on the typical 28-day cycle patterns.

Your body gives you cues that you might be ovulating, such as:

• Changes in cervical mucus: During ovulation, you might notice an increasing quantity of cervical mucus that appears clear and slippery. This is because the body produces more estrogen during the follicular phase, changing the consistency of cervical mucus to help sperm swim towards the egg^5,6
• Pelvic cramps (Mittelschmerz): A lot of AFAB report pain in their lower abdomen during ovulation. The pain is usually described as sudden and sharp, affecting one side of the belly, depending on which ovary releases an egg. Minimal vaginal bleeding may also be observed in some cases⁷
• Increase in basal body temperature (BBT): The rise of estrogen during the follicular phase causes a drop in the body’s lower resting temperature, known as BBT, which remains low until ovulation. After ovulation, hormone levels change. Estrogen no longer rises, but drops. Progesterone, on the other hand, rises, and BBT also has a slight increase. It is best to measure BBT in the morning, as your body is the most rested at that time. If you notice a change in your body temperature, you have likely ovulated⁸
• Changes in libido or mood: The rapid change in hormonal levels can cause a change in libido (sex drive) and mood. This is attributed to increased estrogen levels during ovulation, which enhance libido by increasing the blood flow to the pelvic area and vaginal lubrication⁹

How to track ovulation

Apart from measuring your BBT, you can track your ovulation with specialised apps and over-the-counter ovulation predictor kits. If you are trying to get pregnant, tracking your ovulation and coordinating it with timed, unprotected intercourse maximises your chances of conceiving. 

However, tracking ovulation goes beyond pregnancy. Ovulation is a powerful indicator of your overall body health, so understanding whether it happens and when it happens can offer many benefits, including increased awareness of potential health issues. Recurrent missed ovulations can be a sign of thyroid problems or Polycystic Ovary Syndrome (PCOS). ¹⁰

Recognising when you ovulate can enhance your mind-body connection. You become attuned to the changes and gain insights into how your cycle affects your mood, energy, and appetite. This awareness enables you to plan more effectively, which in turn helps to organise your workouts, social events, and self-care routines.

Common misconceptions

Many people, including AFAB, are not properly educated about menstrual cycles. There are a few myths about ovulation, with the most common being:

Myth 1: You can only get pregnant 1 day a month, and that is the day you ovulate. 

Sperm can last in the female reproductive tract for up to 5 days. Taking this into account, you have high chances of getting pregnant during the whole length of the fertile window, which is 5 days before ovulation, the day of ovulation, and 1 day after. 

Myth 2: Ovulation is on day 14 of the menstrual cycle

While it is common to have a menstrual cycle of 28 days, this is not standard for all women. 

The menstrual cycle varies in individuals, and some women report their regular cycles to be shorter than 28 days or longer than 28 days. Others experience irregular periods recurrently. 

In such cases, ovulation does not occur on day 14. There are different methods that can help you get an estimate of your ovulation.

When to talk to a healthcare provider

Ovulation is an important signal of your overall health. If you experience any of the following, it is advisable to talk to a healthcare provider:

• Suspicions of not ovulating (anovulation)
• Irregular and painful menstrual cycles
• Multiple failed attempts to conceive

With the right expert guidance, you can achieve your goals, whether that is having a regular cycle or getting pregnant. 

Summary

Ovulation is an important phase of the menstrual cycle, and it serves as a sign for reproductive and physical health. Ovulation is part of the fertile window, which is the 6 days per menstrual cycle when there is a high potential to get pregnant. Ovulation occurs under the coordinated activity of many hormones, including FSH, LH, estrogen, and progesterone, and there are usually external signs your body gives you when ovulating (e.g. changes in cervical mucus). When ovulation does not happen, this can signify reproductive issues worth investigating, such as PCOS, or even further complications, such as thyroid issues. Nowadays, mobile apps and over-the-counter ovulation predictor kits make tracking ovulation fast and efficient. Whether you are trying to conceive or not, if you suspect a lack of ovulation, it is important to investigate this further with a healthcare provider to ensure your hormonal and reproductive health is properly assessed and managed.

Ovulation is the process by which an egg is released from one of the ovaries into the fallopian tubes. It usually occurs once per menstrual cycle, which typically lasts about 28 days. The cycle has four stages: the menstrual phase, the follicular phase, the ovulation phase, and the luteal phase. During ovulation, a mature egg is released from the dominant follicle, and if it is not fertilised, the cycle begins anew. Hormones play a crucial role in ovulation.

The four main hormones involved are FSH (Follicle-Stimulating Hormone), which stimulates follicle growth; estrogen, which helps trigger ovulation; LH (Luteinizing Hormone), which causes the egg to be released; and progesterone, which prepares the uterus for possible implantation of a fertilised egg. If the egg is fertilised, the corpus luteum produces progesterone until the placenta takes over. There is a six-day "fertile window" each cycle, including five days before ovulation and the day of ovulation. For pregnancy to occur, sperm must be present during this window, as sperm can survive for up to five days, while the egg lasts about 24 hours after ovulation. Signs of ovulation may include changes in cervical mucus, pelvic cramps, an increase in basal body temperature, and shifts in libido or mood.

People can track ovulation through temperature measurements, apps, and over-the-counter ovulation tests. This tracking can aid in conceiving and also highlight potential health issues, as irregular ovulation may indicate medical conditions like thyroid problems or Polycystic Ovary Syndrome (PCOS). Common myths about ovulation include the belief that one can only get pregnant on the day of ovulation and that ovulation always occurs on day 14 of the cycle. In reality, cycles vary widely among individuals, and ovulation timing is not fixed.