Lena Dunham was in London this week on tour for her debut book, Not That Kind Of Girl.
Back in August, when Dunham announced the event, she tweeted this:
She told the audience: "I started watching Call The Midwife this past summer because I was actually researching for a scene in Girls–spoiler alert–because there are these really great, explicit birth scenes on the show."
"I watched every episode in the course of three days. I was sick for two of them, and then fake-sick for the third. I loved it.
"I tweeted about it and I was sent a special and exclusive Call The Midwife Bicycle Bell. I don't have a bicycle so I just kind of walk around my house like *ding ding* at my dog and my boyfriend and whoever else will accept the behaviour."
Moran had a surprise in store for her friend: "I sent some emails, and now in the audience we have Jessica Raine, Helen George, Charlotte Ritchie (who will appear in the new series), and Miranda Hart."
A visibly delighted Dunham said: "I’m really thrilled, thank you for being here, ladies. It means more than you’ll ever know.”
At the end of Season 3 we found out Adam's sister Caroline was pregnant.
Until then, here's a Season 4 teaser.
Edited to clarify that the character of Caroline Sackler is pregnant, as noted in the comments, not one of the four main characters.