A biological parent is a person who is genetically linked to a child. This typically refers to the individuals who contributed the egg and sperm used to conceive a child. To others, it may also refer to the biological link that is formed by physically carrying a donor egg or donor embryo pregnancy to term.
FertilitySmarts explains Biological Parent
The language behind the many approaches to family-building is complex and typically without consensus. The preferred terminology of one individual may not be that of another.
While not a genetic parent, in the case of a reciprocal IVF and a donor egg or embryo pregnancy, the mother carrying the pregnancy may be considered a biological parent because of the physiological influence her body has on the developing fetus.
In the case of adoption, the parent who has given birth may be referred to as a biological mother or a first or natural mother. Likewise, a father who helped conceive a child may be known as a biological father or a first or natural father.