Conception: the Facts

Conception is when a woman's egg is fertilised by a man's sperm which is then implanted into the woman's womb. 

A woman’s monthly cycle

Every month, hormonal changes in a woman’s body cause the ovaries to release a single egg. This egg passes into the fallopian tubes, which link the ovaries to the uterus (womb).
At the same time, the lining of the womb thickens. This is to prepare it for the possibility of receiving a fertilised egg.

If fertilisation does not occur, the womb lining will break down and will be shed through the vagina. This is a woman’s period. The period is made up of the womb lining and a small amount of blood.

Women of childbearing age have a period approximately every 28 days, although the length of the cycle can vary and between 24 and 35 days is common.

If a woman has unprotected sex with a man around the time of her egg being released, sperm from her partner may fertilise her egg while it is in the fallopian tube. The fertilised egg will then travel to the womb and become embedded in its lining, where it will start to grow.

How Conception Happens

An egg can be fertilised by sperm during the 12 to 24 hours after it has been released from the ovaries.

Sperm can survive in the fallopian tubes for up to seven days, so fertilisation can occur even if sperm entered the fallopian tubes before an egg was released.

During conception, a single sperm from a man penetrates the egg of a woman. The sperm carries the father’s genes, while the mother’s genes are contained in the egg. Once the egg has been fertilised by a single sperm, no more sperm can enter.

The fertilised egg, called a zygote, continues to move down the fallopian tubes, until it reaches the womb. Here, it will implant itself into the lining of the womb (about 6-10 days after ovulation), where it begins to grow.

Until eight weeks after conception, the implanted zygote is called an embryo. After this it is called a foetus.

For most women, the first sign that they are pregnant is a missed period. A few days after that missed period, a urine test can confirm the pregnancy.

Trying to conceive

It is important for women of child bearing age to understand their monthly cycle to understand when you are ovulating.

Every month, hormonal changes in a woman’s body cause an egg to be released from the ovaries. This egg travels into the fallopian tubes, which connect the ovaries to the uterus (womb). This is called ovulation.

You’re most likely to get pregnant if you have sex within a day or so of ovulation. Ovulation usually happens about 14 days after the first day of your last period.

An egg lives for about 12-24 hours after it’s released and in order to conceive,  a sperm must fertilise the egg within this time. Sperm can live for up to seven days inside your body, which means an egg is often fertilised by sperm that entered the body before the egg was released.

Many professionals would recommend couples who are trying to conceive to have frequent sex, every two to three days, and to focus on taking the stress out of trying for a baby.

Some information taken from:

http://www.nhs.uk/Livewell/Fertility/Pages/Fertilitythefacts.aspx


ConceptionCatriona Barry