External genital organs are formed in the foetus by the end of

By the end of 12 weeks (first trimester), external genital organs are well-developed in the foetus.

After one month of pregnancy, the embryonic heart is formed. By the end of second month of pregnancy, the foetus develops limbs and digits. The first movements of the foetus and appearance of hair on the head are observed during the fifth month. By the end of about 24 weeks (end of second trimester), the body is covered with fine hair, eyelids separate, and eyelashes are formed. By the end of nine months of pregnancy, the foetus is fully developed and is ready for delivery