Six ways to be a parent.

As far as I can tell, there are six (orthogonal) ways to be a parent, consisting of four modes of motherhood, and two of fatherhood.

How to be a mother:
1. Contribute the ovum: "mitochondrial motherhood" (since the child will inherit her mitochondria).
2. Contribute one half of the nuclear DNA: "chromosomal motherhood".
3. Provide the site of gestation: "uterine motherhood".
4. Raise the child as its mother: "social motherhood" (there's probably a better term).
One might like to also consider the breast-feeder as a motherhood role, in which case this could be called "mammary motherhood" (or "wet nurse" if this is the only role played).

When a women plays all of the first three roles, she can be called the "biological mother". When she plays the second role we may call her the "genetic mother" ("chromosomal" would be used when it is necessary to indicate that the first role was not played). When she plays the third role, but not the second, we would call her the "surrogate mother". If she plays only the fourth, she would tend to be the "adoptive mother".

How to be a father:
1. Contribute one half of the nuclear DNA: "biological fatherhood" (no need to specify "chromosomal").
2. Raise the child as its father: "social fatherhood".

There are fewer fatherhood roles, and hence less scope for further terminology. We may only say that non-biological father would tend to be an "adoptive father".

Strengths:
This model provides recognition for up to six different parents of a child, illustrated by the following (rather tragic) example:

Example 1:
Allison and Arthur want to have children. An unfortunate set of circumstances prevent them from this. Allison's ova somehow lack the mechanisms to allow them to divide when fertilised, and her uterus is unfit for gestation. Allison is able to find an egg donor, Belinda, and procures several ova. The nuclear material of these ova is removed, and replaced with nuclear material from Allison's ova. These are then fertilised with Arthur's sperm. Allison's good friend, Cordelia, offers to be surrogate mother. Seven months into the pregnancy, Allison and Arthur die in a car accident. Cordelia, in extreme distress, goes into labour, and dies in childbirth. In accordance with the very meticulous will of Allison and Arthur, the child, Eileen, is given up for adoption, and taken in my Delilah and Brendan. Thus, Eileen grows up with the knowledge that she has six parents, Allison, her chromosomal mother, Belinda, her mitochondrial mother, Cordelia, her uterine mother, Arthur, her biological father, and Delilah and Brendan, her adoptive parents.