Phases of the menstrual Cycle – 2. The Ovulatory Phase.

Young woman in grey linen blouse lies on her back and holds both hands on her stomach.

What is ovulation?

Very simply, roughly once a month a follicle ripens and releases an egg. Ovulation is a process that happens in the female body when an egg is released from the ovary and travels down the fallopian tube, where it can potentially be fertilized by sperm. This usually happens once a month, around the middle of a woman’s menstrual cycle. Hormones in the body trigger the release of the egg and prepare the uterus for a possible pregnancy. If the egg is not fertilized, it will break down and be expelled from the body during menstruation. Ovulation typically occurs around day 14 of the menstrual cycle, based on a 28-day cycle. Although it is very important to remember that this is an “average”. Every woman is an individual with her own cycle length and this cycle length can also vary from month to month depending on lifestyle influences, sickness, stress, travel etc.

The process of ovulation begins with the release of the follicle-stimulation hormone (FSH) which causes several follicles, each containing a single immature egg, to rise to the surface of the ovary. A surge in luteinising hormone levels causes the ovarian follicle to tear and release a mature oocyte (egg) from the ovary. Each cycle sees many eggs mature - but only one (occasionally a second) reaches the point where it is released from the ovary. All the others die and are absorbed by the body. A woman can expect to ovulate about 500 times in her lifetime, until all her eggs are used up and she enters menopause.

After release the egg travels down the fallopian tube towards the uterus. Ovulation is the only time in your cycle that you can get pregnant. If the egg isn’t fertilized and pregnancy doesn´t occur the egg will be absorbed into the body. After the follicle releases its egg, it changes into the corpus luteum. This structure releases hormones, mostly progesterone and some oestrogen, the progesterone causes a minute rise in basal body temperature which lasts until the next period. It is this tiny rise in temperature that femSense can measure and which confirms ovulation. The rise in temperature is a direct result of ovulation – the follicle changes into the corpus luteum, which in turn causes a rise in basal body temperature – and is therefore a reliable confirmation that ovulation has taken place. After ovulation the levels of oestrogen fall and the levels of progesterone rise. If an egg has been fertilised progesterone will continue to rise, if there has been no fertilisation the progesterone will drop, the lining of the womb sheds and leaves the body as a period.

The time shortly before and immediately after ovulation is a woman’s most fertile period. This ertile window is shorter than most people realise - it only lasts a few days. Shortly before and during ovulation the environment inside the uterus is very sperm-friendly, so that sperm can survive for up to 4 days waiting for an egg to arrive. The egg itself is fertile for about 24 hours after ovulation, after which it dies. This means you have approximately 5 days per cycle where you are at your most fertile and pregnancy is likely.

Symptoms of Ovulation

What does ovulation feel like? There are a few common physical indications of ovulation that you can monitor, if you want to know if and when you ovulate. The hormonal changes which cause ovulation also cause other symptoms in your body, which can be so mild that you may not even be aware of them. You can learn to watch for them to help recognize when ovulation might be happening

  • A rise in basal body temperature
  • Cervical Mucus Changes
  • Mittelschmerz
  • LH surge

Fun Fact: Did you know that little girls are born with all their eggs? The developing female fetus has about 7 million eggs, weeks before they are even born! The body absorbs most of the eggs before birth but about 2 million eggs are still there when a baby girl is born and about 500,000 are still there when she enters puberty and starts to menstruate. A woman’s remaining egg supply, capable of producing a baby, is known as her “ovarian reserve”. This basically means that a woman’s eggs are always a few months older than she is.