Changes

A '''human embryo''' is the first stage of human development.   

A '''human embryo''' is the first stage of human development.   

    

    

It is develops by cell multiplication of a zygote, formed by the fusion of the male [[gamete]] (spermatozoon or "[[sperm]]") and female gamete ([[ovum]] or "egg"). This is called [[fertilization]] and usually occurs in the proximal portion of the female reproductive tract. After fertilization, an embryo must implant in the lining of the uterus.  If it does not, several problems can occur.  The pregnancy can be lost via miscarriage. This often occurs without the knowledge of the mother. A tubal pregnancy can occur. This is a medical emergency requiring prompt intervention.   

It is developed by cell multiplication of a zygote, formed by the fusion of the male [[gamete]] (spermatozoon or "[[sperm]]") and female gamete ([[ovum]] or "egg"). This is called [[fertilization]] and usually occurs in the proximal portion of the female reproductive tract. After fertilization, an embryo must implant in the lining of the uterus.  If it does not, several problems can occur.  The pregnancy can be lost via miscarriage. This often occurs without the knowledge of the mother. A tubal pregnancy can occur. This is a medical emergency requiring prompt intervention.   

== Controversies ==

== Controversies ==