Codex: Egg Splicing

When two females want to have a child with the genetic traits of both mothers but don't want a sperm donor, this technique is used. It is also used to create more stable hybrid children, say two completely incompatible races want to have a hybrid baby. Egg Splicing. With this technique, the child will always inherit more traits from the host mother over the spliced in DNA. Say that a human woman and a Martian woman want a child together. If the Martian woman is the host mother, with the human DNA spliced in, then the child will have more Martian traits. If you reverse this, then the child will have more human traits. Multiple DNA samples can be spliced in, it's not limited to two and the ratios can be tweaked if the species are similar enough. The technique is a gift from the Automaton race as a token of good faith.