It wasn’t a big topic in the first two debates, but abortion finally came up as a major point of contention between Donald Trump and Hillary Clinton in the third debate, and Trump made a major mistake while discussing the topic. Trump gave the impression during the debate that he believes abortion can happen in the ninth month of pregnancy, but that is completely incorrect.

“I think it’s terrible if you go with what Hillary is saying… in the ninth month you can take the baby and rip the baby out of the womb of the mother just prior to the birth of the baby,” Trump said during the debate. “Now, you can say that that’s okay, and Hillary can say that that’s okay, but it’s not okay with me. Because based on what she’s saying and based on where she’s going and where she’s been, you can take the baby and rip the baby out of the womb in the ninth month, on the final day. And that’s not acceptable.”

But not only do ninth month abortions not happen, even abortions after 21 weeks are incredibly rare. Only 1.3 percent of abortions happen after that point, and about 80 percent of them are for birth defects, which could include anything from Down syndrome to conditions that would present problems down the road that would threaten the child’s life. Any birth defects that crop up after 24 weeks are very severe and may be completely incompatible with a normal, health life, or life at all.

In addition, such situations can also threaten the health of the mother.

A small portion of the already tiny 0.3 percent of abortions after 21 weeks will be elective abortions. But even in this case, there are no ninth month abortions.

Trump has said he was pro-choice for much of his life, until accepting the Republican nomination for president. Although he did say in a 2000 book that he supported bans on partial-birth abortion.

“I support a woman’s right to choose, but I am uncomfortable with the procedures,” he said according to the book. “When Tim Russert asked me on Meet the Press if I would ban partial-birth abortion, my pro-choice instincts led me to say no. After the show, I consulted two doctors I respect and, upon learning more about this procedure, I have concluded that I would support a ban.”