In the cases where the women are pregnant, that pledge extends to their unborn child.
Woman No 1
A woman in a committed lesbian relationship now believes she is pregnant. Her cycle never extended beyond 26 days and, this week, was three days late. She had felt ill and shown other physical signs of pregnancy.
She spoke to the Herald on Sunday after getting approval from Bill Johnson to do so. The three had signed a contract which featured a clause he had written into it to protect his identity.
She said that at the time of the donation - two weeks ago - he had only told her and her partner of one other woman he had donated to who was three months pregnant.
Johnson met the couple initially in a public place and told them he would be overseas for Christmas.
"He was in a hurry," she said. "We were looking at December. He said 'If you want it done, we'll do it now'."
Her partner said the couple turned to the internet after finding fertility treatment was too expensive.
She said it was also difficult for lesbian couples to find men who were willing to donate to same-sex parents.
Lesbian couples were often the last people donors considered, she said.
The couple were aware the internet meant it was harder to screen donors. She said Johnson arrived with a copy of a sexually transmitted infection test showing a clean bill of health - but the name had been deleted to obscure his identity until they signed a contract protecting his confidentiality.
The couple were still unsure if it was genuine and sought help from the Herald on Sunday to confirm details on the form.
They asked Johnson if he was in a relationship. "He said it was not an issue." The woman said she specifically looked for a wedding ring and could not see one.
She said Johnson would have been in no doubt the couple were in a committed relationship - he made no comment on the issue. She laughed when she was told he had campaigned against gay marriage.
The pair were still excited about the impending child. "We found Bill to be really nice. He's a really supportive guy."
Woman No 2
A single woman in her late 30s said she had attempted to become pregnant from sperm donations made by Johnson over the past four months.
She said she became aware during the donations Johnson was helping two other women and one was pregnant.
"I was a little bit shocked he hadn't mentioned it earlier."
Then, recently, she told him she was surprised to see his profile on one of the online sperm donation sites. She said Johnson told her he had intended to remove it from the website.
She said Johnson had told her of a partner, who was informed of his practice as a donor. "As far as I was aware, she did know it was happening."
Woman No 3
Another woman, waiting on conception, said she was aware there were other women he was helping and "other children".
"He said his wife was aware of what he was doing."
