Call the Midwife is a period drama broadcast on BBC One.
The cast appeared in a comedy sketch for 2013's Comic Relief which combined elements of the series with that of the Channel 4 documentary series One Born Every Minute, and also featured Matt Smith in character as the Eleventh Doctor.
A number of cast members have also appeared in Doctor Who productions individually; Jessica Raine portrayed Emma Grayling in the Series 7 episode Hide, and Jenny Agutter and Pam Ferris have also voiced characters for audio dramas.