Everyone understands that you can't tell in the first few weeks but the question remains at the back of your head and is normally the first thing uttered, after 'congratulations', by people you inform of your pregnancy. You're also bound to have family members or friends of the family say things like 'By your shape it's definitely going to be a girl' or something similar.

But how much truth is there in these remarks and are any reliable?

Belief: The shape of your belly indicates the sex of the baby - lower and fuller a boy, wider and higher for a girl.

Truth: In actual fact the height of the baby and the shape of your 'bump' is determined by the baby's position and your uterine and muscle tone.

Belief: You can determine the fetal sex by it's heart rate.

Truth: Studies have actually been conducted in this area although there has been no conclusive evidence to support the theory. The normal heart rate of an unborn child is 110-160 beats per minute. People think that if it's over 140 it's a girl, less for a boy.

Belief: The necklace trick - get a ring place it on a necklace and hang this over your belly. If it sways from side to side it's a girl, if it goes in a circular motion it's a boy.

Truth: There is no truth in this whatsoever - although it may be a fun game. The likelihood is that you are subconsciously moving the necklace in the direction you want to - this might be an interesting thing to get your partner to do - after asking him if he's any preference of course!

The real truth: There are only 3 effective ways to tell the sex of your unborn child -

Method 1 - Chorionic Villus Sampling (CVS) This is only normally done if there is a chance of a serious gender related problem. It is usually performed around 10-12 weeks.

Method 2 - Amniocentesis Again this is only normally done if there is a risk of a serious genetic condition and is performed around 18-20 weeks by taking a sample from the amniotic fluid and analysing the babies cells.

Method 3 - An Ultrasound Scan A baby's sex can be determined from around 18 weeks and this is normally an effective way to determine the sex of your baby. Bear in mind that on the day of your scan that the baby may be facing the wrong way or another part of its body could be covering its genitalia. Some hospitals won't tell you the sex of your baby for fear of making a mistake or for worry that in a small number of cases it may lead to a termination request. If you are told when you have your scan be aware that it's not always 100%.

The 100% Method After giving birth look down or ask the midwife or doctor!