Dossier: Planning a family

Five key questions on ovulation

If you’re trying to fall pregnant and don’t want to leave it entirely to chance, it’s important to familiarise yourself with ovulation, because this is what determines your fertile days. We answer five key questions on ovulation.

What is ovulation?

Ovulation refers to the release of a mature egg from the ovaries. After release, the egg travels down the Fallopian tube towards the uterus. It is only at this point that the egg can be fertilised by a sperm, resulting in pregnancy.

This process is triggered by increasing oestrogen levels during the cycle. As soon as the oestrogen level reach a specific value, the concentration of luteinising hormone (LH) increases. This is the signal for the ovaries to release an egg. Ovulation kits can be used to determine the increase in the LH value to determine the time of ovulation around 24 hours in advance.

When does ovulation take place?

Release of the egg generally occurs on the 14th day of a cycle, with a standard cycle lasting 28 days. However, the body doesn’t tend to stick to theoretical guidelines, which means that a woman’s cycle can vary. Furthermore, ovulation is the result of a complex hormonal chain reaction that starts in the previous cycle, and it can be different each time. In other words, most women don’t ovulate on the 14th day, and ovulation doesn’t always occur on the same day of their cycle. As a result, it’s not easy to determine the exact moment of ovulation.

When and how long are you fertile?

An egg cell can only be fertilised when it has been released from the ovary. This is known as ovulation. After ovulation an egg cell can survive for a maximum of 24 hours. However, the fertile window begins five days before this. This is because, in good conditions, sperm can survive up to five days and wait for the egg to appear. In other words, there are a total of 6 fertile days (5 + 1 = 6) per cycle. Studies indicate that you have the best chances of conceiving if you have sex on the two days before ovulation.

When is a fertilised egg implanted?

Once an egg is fertilised, its genetic material merges with that of the sperm cell. The result of this merger is a blastocyst, which migrates through the Fallopian tube to the uterus during the first three days of development. Once the blastocyst arrives in the uterus, it can take a few days to embed itself in the uterine wall. In general, the time from ovulation to implantation of the blastocyst and closure of the cervix can last from seven to twelve days.

What are the common signs of ovulation?

Unfortunately, there’s no way of being 100% sure that you’re ovulating. However, with a little experience and by listening to your body, there are a number of telltale signs you can pick up on:

  • Your resting pulse increases by about two beats a minute two to five days before ovulation. You can measure your pulse at your wrist or carotid artery.
  • Your breasts and nipples can feel sensitive in the days before and after ovulation. 
  • About 70% of women experience inguinal swelling during ovulation. You can feel the glands on both sides of the groin near the pelvis. The gland is only swollen on the side of the body from which the egg is released. 
  • Spotting may occur during ovulation, making it possible to determine your fertile window. 
  • The cervical mucus changes consistency in the days before ovulation due to the increased oestrogen levels. This is the body preparing for ovulation. The discharge should be clear and smooth, similar to raw egg white. 
  • Many women feel a dull ache around their pelvis during ovulation, known as Mittelschmerz. 
  • Measuring your basal body temperature (BBT) is not 100% accurate, because errors can easily occur. Even handling the thermometer can distort the results. Apart from this there’s a lack of scientific evidence. It’s proven that your temperature increases following ovulation, but by then it’s already too late to fall pregnant in that particular cycle.