This free course, Early development, looks at the human being in the context of an individual life cycle, examining some of the processes that contribute to the formation of a new person. After a brief discussion of historical ideas about human conception, and about contraception to the present day, we look at the cells involved in the conception and development of a new individual. Gamete production (that is, production of mature cells able to unite with another in sexual reproduction) in both men and women is introduced and the role gametes in fertility and, when things go wrong, infertility is explained. We then discuss the early development of a new individual, along with some thoughts on women's experience of pregnancy.