BBC has renewed Call the Midwife for Season 4 and has also confirmed that there will be a Christmas Day Special episode later this year, according to reports.  

Call the Midwife is one of the BBC's highest rated dramas, and has experienced success on both television and DVD sales.  So it was no surprise when the show was renewed for a Season 4, and in cast rumors surrounding the upcoming season, it has been claimed that actress Vanessa Redgrave will appear on-screen as Jennifer Worth, the narrator whose life has become the basis of the story.

The Mirror UK reported that Redgrave will specifically appear on the show's Christmas Special, and then continue in Season 4 as the narrator. Lead actress Jessica Raine also played Worth's role when she was younger. 

The new cast lineup includes Linda Bassett (East is East, Lark Rise to Candleford) and Charlotte Ritchie (Fresh Meat). 

Unfortunately for Raine's fans, her role as Jenny Lee will not be reprised.  In her interview with The Independent, she said that she is exploring career options other than Call the Midwife. 

"It's been a real privilege to help bring Jenny Lee's story alive and amazingly satisfying to see how the public have embraced the series, but as is in keeping with Jenny's story, it's time for me to explore pastures new," Raine added.

Call the Midwife first aired on BBC in the UK on January 15, 2012 while the second season had its premiere on January 20, 2013.  The show's fourth season is expected to air in January 2015 shortly after its Christmas 2014 Special episode.