Google shows it's International Women's Day, celebration and call to action for an often oppressed majority.
It's possible to do an episode about the treatment of different sexes without being preachy or offensive, or silly, but it's certainly a fine line. An adventure focusing on a female PC would probably be a safer bet, or a Celebrity Historical about a woman you admire or would find entertaining to feature, or maybe something referencing it in passing, like a Women's Lib meeting in a late 60s adventure. Perhaps a trip to the first IWD at a pinch.
Or something more metaphorical about the oppression of a vital group?
Hmm. Daleks all sound male, so do Cybermen despite presumably being about 51% female brains in their armour, and there are no female Sontarans nowadays...
Then there's the possibility of a female Doctor.
Who would you cast? It depends if it's a new Lumley-style regeneration (Tilda Swinton!) or a female version of a current Doctor (Jaime Winstone as Eleven, replacing Sue Perkins as Ten) or some other way of switching him over for a session or so, if not permanently.
Kammerice's 38 Farscape Barenaked Ladies Song Plots includes "I’ll Be That Girl" about switching the crew's genders to catch them in discriminatory laws and traditions. That could make for a funny one-week-only treatment of the idea. I can imagine the Doctor being pretty casual about the whole thing.
"Hey! Look at this! I'm a woman! Big flash of light, turned into a woman! Isn't that odd?"
"... You're taking this very well, Doctor."
"Course! It's a new experience, a new frontier! All these things to try - ooh, kissing men, what do you think?"
"I didn't necessarily mean you, Rory."
"Typical. Twenty minutes as a woman and I've been kidnapped. I always used to wonder why women get kidnapped more than men. I suppose it makes sense, we're not as fast and we're more portable..."
"I see, turn me into a woman so the authorities won't listen to me. Very clever. And also rather rude. Don't think I approve."
"I wear a dress now. Dresses are cool! Whoops! Not so sure about the shoes, though."