Democratic vice presidential candidate Tim Walz has repeatedly told the story of him and his wife, Gwen Walz, struggling to have children and turning to fertility treatments for help.

On Tuesday, Gwen Walz offered more detail, specifying that they did not use in vitro fertilization, or IVF.

In a statement from the Democratic presidential campaign, Gwen Walz said she and her husband used a process called intrauterine insemination ― and that they hadn’t told anybody except a next-door neighbor about what they were going through.

“She was a nurse and helped me with the shots I needed as part of the IUI process,” Gwen Walz said. “I’d rush home from school, and she would give me the shots to ensure we stayed on track. Many of our closest family and friends were surprised when we shared these experiences so many years later.”

In public comments, Tim Walz has usually brought up his own family’s infertility in the context of IVF without specifying that they used IVF, instead using the terms “fertility treatment” or “things like IVF.”

On at least two occasions, however, Walz has been less precise, leaving the impression they had used IVF, which is more intensive than IUI and involves retrieving eggs and fertilizing them outside of the womb.

“Thank God for IVF ― my wife and I have two beautiful children,” Walz said last month on MSNBC.

And in a clip circulated this month by the Kamala Harris-Tim Walz campaign, Walz said if it were up to Republicans like vice presidential candidate JD Vance, he wouldn’t be a father.

“If it was up to him, I wouldn’t have a family because of IVF and the things that we need to do reproductive ― my kids were born through that way,” Walz said.

Vance, who has accused Walz of lying about his military service, said Tuesday that Walz had lied about IVF, referring to stories with the new information from Gwen Walz.

“Today it came out that Tim Walz had lied about having a family via IVF,” Vance said on social media. “Who lies about something like that?”

A spokesperson for the Harriz-Walz campaign said Walz was not intentionally trying to mislead with the less precise statements, saying people use IVF to mean all the types of fertility treatments.

“Governor Walz talks how normal people talk. He was using commonly understood shorthand for fertility treatments,” campaign spokeswoman Mia Ehrenberg said.

“The Trump campaign’s attacks on Mrs. Walz are just another example of how cruel and out of touch Donald Trump and JD Vance are when it comes to women’s healthcare,” Ehrenberg said. “Infertility is a deeply personal journey, but the Governor and Mrs. Walz came forward to share their story because they know that MAGA attacks on reproductive rights are putting all fertility treatments at risk.”

IVF became a political flashpoint in February after the Alabama Supreme Court ruled that embryos are children, meaning the intentional disposal of unused embryos from IVF patients was murder. The ruling followed the U.S. Supreme Court overturning the federal right to abortion in 2022 and prompted several Alabama IVF clinics to pause operations.

Democrats in Congress have since sought to protect IVF access, but Senate Republicans blocked a bill last month, arguing that it was not necessary. Former President Donald Trump, who appointed the Supreme Court justices who overturned Roe v. Wade, has insisted that Republicans support IVF.

Gwen Walz said the Alabama episode prompted her family to speak out.

“After seeing the extreme attacks on reproductive health care across the country ― particularly, the efforts in Alabama that jeopardized access to fertility treatments ― Tim and I agreed that it was time to formally speak out about our experience,” she said. “Our experience taught us that there is always hope and we hope other families find solace in our story.”