Up to three months

The incredible, rapid development of the foetus continues throughout this month. At the beginning of the ninth week the foetus is around five centimetres, but by twelve weeks it will have reached up to eight centimetres in length, weighing about two ounces.

At nine weeks, most of the internal organs are present although not fully developed. Eyes and ears also develop quickly at this stage and the beginnings of a skeleton starts to evolve. By week ten the foetus is capable of making lots of movements with its limbs, which the mother will not yet be able to feel internally. The beginnings of fingers and toes are also just about visible, though by week twelve this will have moved on to the growth of fingernails. At week ten, the foetus can also wee, discharging urine into the amniotic fluid. Crucially, the external genitals of the foetus are also visible, differentiating the boys from the girls.

Mums-to-be may notice that their waistlines start to get a little thicker during their third month. This is not due to the size of the baby: it is more likely to be from fluid retention. It is also quite normal to gain some weight at this stage - a healthy development. In addition, some mums-to-be find that they are feeling particularly emotional and even close to tears. This is an entirely natural way to feel, brought about by increased levels of hormones. The great news is that from the third month onwards, miscarriage is much less of a risk and also that at around this time morning sickness should start to disappear.

In terms of planning, make sure that you have established contact with your midwife and think ahead to the type of birth you would like to have, whether at a hospital or elsewhere. Also, think about booking antenatal classes - they are available through the NHS, but courses such as the NCTs fill up quickly.