What is Fertilisation?

11th April 2022

While it may not always be at the forefront of anyone’s mind, fertilisation is something that, for some, could play a huge role in a person's life. 

People will often assume that fertilisation is just something that happens as and when it does, and many people will not understand the process that occurs during fertilisation, or the factors that can affect it. In this article, we will explain what exactly fertilisation is, as well as the process behind fertilisation. We will also explain the full cycle of fertilisation, from conception all the way to birth, as well as providing helpful tips that you can use if you are struggling with conceiving a child. 

How does fertilisation work?

A pregnant woman holding her stomach.

Simply put, human fertilisation is when the nucleus of a sperm cell fuses with the nucleus of a fertile female egg inside of a woman’s fallopian tubes. Whilst there are a few ways of this process occurring, the most common is when a man ejaculates inside of a woman during unprotected vaginal sex. Other ways that fertilisation can occur include IVF treatment, where an egg and sperm cell are removed from the human body and fertilised in a laboratory. 

Whilst some couples may find it easier to conceive naturally, others may turn to treatments such as IVF when they are ready to start a family. However, these treatments can be lengthy and expensive, so couples may look for other ways to boost their fertility. Understanding the process of fertilisation can help with this, and knowing if there are any factors that could potentially be hindering chances of conception can be useful information for a couple to know. Check out our previous blog regarding five factors that can affect your fertility. 

Fertilisation can only occur during certain times of the month, according to a woman’s ovulation cycle. Whilst you should always practice safe sex to avoid STIs, you should also be careful if you are not yet ready to start a family. If a woman knows when she is most fertile, she will be able to adapt her and her partner's sex lives around to further boost their chances of conception. To find out when you are most fertile, there are ovulation tests you can use that will provide further detail into your cycle.

What happens when a woman gets pregnant?

Following the egg and sperm cells nuclei fusing together, the process of growing a child can begin. For a human woman, the gestation period will be around 9 months, however, some can be longer and some can be shorter. Following the fertilisation of an egg, a woman may begin to notice signs that she may be pregnant. 

The most common signs of pregnancy include missing a period, nausea, vomiting, and increased fatigue. Once a woman has a positive pregnancy test she should then book in to see her doctor. Pregnancy is split up into trimesters, periods of around 12 weeks in which the baby will develop. The first trimester is from weeks one to 12, trimester two is from weeks 13 to 26, and the third trimester is from week 27 until the delivery of the baby. At the end of the first trimester, the baby will be around three to four inches long. At the end of the second, however, the baby will be between 13 to 16 inches long and will weigh roughly around 1.3kg. 

How long is a woman fertile for?

The average fertility period for a woman during her ovulation cycle will be from around the 12th day of menstruation and will last for around four to six days. This period is known as your fertile window. It is important to note that all women’s bodies will behave differently, and the time when a woman is most fertile can vary from person to person. There are ways to test when you are most fertile, with Babystart products being available to test both fertility and ovulation. 

A woman fanning herself.

In general, a woman is in her fertile years from when she first gets her period until the age of around 45. A woman’s peak fertile years will be around her mid-20s, and she will begin to decline in fertility from around the age of 34/35. This does not however mean that she is unable to get pregnant, and safe sex should be practised if she is not wanting to have a child. At around the age of 45, the body will begin to enter menopause. This is when the female body will stop producing fertile eggs and periods will end. This also marks an end to the woman being able to naturally conceive. Again, it is important to note that these ages do not apply to all women as a whole and will vary from person to person. 

How can you boost fertilisation?

Previously we have touched upon ways that you can both boost your sperm quality as well as the quality of egg a woman produces. Knowing about the process of fertilisation is already a good step in helping your chances of conceiving. Far too often people will be attempting to have sex either not enough or too often, and most of the time they will be having unprotected sex during the wrong time period. If you understand how the human body works and the process it needs to take in order to conceive naturally then you are already ahead of the curve. 

Of course, there are the usual things that you can do in order to live a healthier life. Regular exercise and cutting out bad habits such as drinking or smoking can lead to an overall healthier body and thus healthier, more natural bodily functions. Changing your diet can also attribute to having an easier process of fertilisation. Steer clear of fatty unhealthy foods and ensure you are eating and drinking vitamin-rich foods and drinks such as fruit and fruit juices.

There are also supplements for both men and women that can be purchased that can aid with fertility. These supplements are designed to give your body the essentials it needs in order to boost fertility. Taken when trying to conceive, or taken on a regular basis whether you are trying or not, these supplements can give your body a kick start.