#SECGuidance The beginning of the capacity to use is marked by the moment of the person's birth. This is the rule stated in Article 35, paragraph 1 of the Civil Code. Until birth, the child does not have a distinct individuality but is merely a part of the mother's biological system (pars viscerum matris). The embryo or fetus — the distinction being made according to the stage of development of the unborn child — does not have an autonomous existence, is not a complete human being and, as a result, does not have legal personality.

The date of birth is specified in the birth certificate, which includes a special section for this purpose and which generally constitutes the means of proof of this fact generating civil status.

From this rule, there is also an exception, established by Article 36, paragraph 1 of the Civil Code, according to which the rights of the child are recognized from conception, but only if he is born alive. To determine the moment of conception — that is,