Weeks 0-4 of Pregnancy


Fertilisation occurs when one of the millions of sperm penetrates the outer layers of the egg and fuses with its nucleus. At this point your baby’s entire genetic coding, including behaviour, eye colour, height, hair colour, intelligence and sex, is determined.

The cluster of cells, called a morula, rapidly multiplies as it travels down the fallopian tube towards the uterus or “womb”.

On its arrival in the womb, the morula becomes known as a blastocyst and floats freely within the cavity for about three days before embedding in the wall lining and linking to the blood supply. From this moment your growing baby is called an embryo. Already it has grown from one cell to a mass of hundreds of cells and a placenta begins to form around it, although this will not be fully functional until about week 14.

A plug of mucus has formed at the entrance to the womb acting as a barrier to infection. Seven days after implantation, chemical signals called hormones prevent a period from starting. The primitive placenta produces a hormone called human chorionic gonadotrophin (HCG) that passes into your urine. This can be detected by a pregnancy test that will confirm a positive result 12-16 days after fertilisation. Some women can tell instinctively when they have conceived although most remain unaware.


This is the most crucial time of your baby’s development. Start taking 500mcg of folic acid daily. This B vitamin has been proven to reduce the risk of your baby being born with skeletal deformities and neural tube defects by up to 70 per cent. Folic acid deficiency has been linked to cleft palate, skeletal deformities, undeveloped organs, paralysis of the legs, incontinence, malformations of the heart and blood vessels, nervous system disorders and mental retardation.

You can find an abundance of folic acid in bright green leafy vegetables, particularly broccoli and spinach, as well as pumpkin, avocados, peas, dried beans and wholegrain breads. For a fabulous collection of nutritious and tasty recipes, click here .

Your baby’s major organs are now forming. At this stage, your baby is vulnerable to alcohol, drugs, smoking and infections. There are plenty of grounds to quit smoking and cut down on coffee and alcohol during pregnancy. All have been linked to abnormalities and growth deficiencies in your developing baby. Also, check with your doctor to see if you have been immunised against German Measles/Rubella.

Listen to your body. If you are really worried call your doctor, no matter how trivial your concern may seem.

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