Definition and Types In 2007 the Committee on Ethical Aspects of Human Reproduction and Women’s Health of the International Federation of Gynecology and Obstetrics (FIGO) defined the pregnancy as part of the human reproduction process that begins with the conceptus implantation in women. Pregnancy begins at the time of implantation and ending with delivery. The legal definition of pregnancy is the medical definition: for the World Health Organization (WHO) pregnancy begins when the deployment ends, which is the process that begins when the blastocyst adheres to the wall of the uterus (about 5 or 6 days after fertilization). Then the blastocyst through the uterine lining and invades the stroma. The implementation process ends when the defects in the surface epithelium is closed and completes the process of implantation, beginning then the pregnancy. This occurs between days 12-16 after fertilization.In humans, women go through a process that lasts about 40 weeks from the first day of last menstrual period or 38 weeks from the day of fertilization, equivalent to about 9 months. It is called ectopic or tubal pregnancy that occurs outside the uterus, abnormal implantation of the fertilized egg (usually one of the two fallopian tubes).