A California professor has issued a grovelling apology to his students for telling them that only women can get pregnant.

The professor on an endocrinology course used the term "pregnant women" during his lecture, but then quickly backtracked and apologised.

In a recording of the lecture, he can be heard saying, "I'm very sorry for that. It was clearly not my intention to offend anyone. The worst thing that I can do as a human being is be offensive.

"I said 'when a woman is pregnant,' which implies that only women can get pregnant and I most sincerely apologise to all of you," he said.

The recording was shared by journalist Katie Herzog, who received them from a medical student attending the lecture. The student has admitted that some of her classmates consider it transphobic if someone acknowledges biological sex.

In her piece, Herzog wrote that "when sex is acknowledged by her (the student's) instructors, it's sometimes portrayed as a social construct, not a biological reality."

The medical student revealed that she and her fellow trainee medics had access to an online forum where students can correct their professors for using gender-specific terms such as "male", "female", or "breastfeed" instead of gender-neutral terms like "chestfeed."

The online forum allows students to "lodge their complaints in real time during lectures."

The student recalled how one time a professor started crying because she "upset by students calling her out for using 'male' and 'female'."

She told Herzog that other students had circulated petitions at the start of a school year to "name and shame" professors for engaging in "wrongspeak".

"Wrongspeak" according to the petitions included use of the pronouns "she" and "her" or the terms "father" and "son."

The student also spoke about another professor who became the subject of a petition for calling a transgender male "a man changing into a woman," which upset some students because "it implies that the trans woman wasn't always a woman".

She added that "since the petitions were sent out, instructors have been far more proactive about 'correcting' their slides in advance or sending out emails to the school listserv if any upcoming material has 'outdated' terminology." 

The ideology sweeping through medical schools and the medical community as a whole, Herzog says, has led to a reduced emphasis on the different medical experiences faced by males and females.

Herzog's piece, titled "Med Schools Are Now Denying Biological Sex", includes quotes from established medical professionals, who agree that the imposition of "woke ideology" into the medical community that ignores or downplays the real differences between the two biological genders will have disastrous consequences.