Human pregnancy lasts for nine months and it officially begins after implantation i.e. 8th day after fertilization.The sign of developing foetus is first recorded at the end of 1st month as heart sounds are cleary audible. The foetus develops limbs and digits by the end of 60 days. Major systems also develop in the third month of pregnancy.Hence as the first trimester (3 months or 12 weeks) is completed the foetus has developed organ systems and limbs and digits. The first movements of the foetus and appearance of hair on the head are usually observed during the fifth month. By the end of 24 weeks (second trimester), the body is covered with fine hair, eye-lids separate, and eyelashes are formed.