<P> The idea of adapting Worth's books for television was initially dismissed by the BBC, but revived after Danny Cohen took over the post of Controller of BBC One . A full series was commissioned in 2011 and writer Heidi Thomas adapted Worth's books for the screen . The first episode was broadcast on 15 January 2012 and the initial series of six episodes drew positive reviews and large viewing figures, said by the BBC to be the highest audiences achieved by a new drama series on BBC One since the corporation's current method of measuring audiences began in 2001 . Following the second episode, the BBC announced that a second series, expanded from six to eight episodes, had been commissioned . In September 2012 the programme won the Best New Drama award and Hart was named Best Actress at the TV Choice Awards . </P> <P> The second series began on 20 January 2013, and during the run BBC Controller for Drama Ben Stephenson announced that he had commissioned a 2013 Christmas special and a third series of eight episodes to be broadcast in 2014, despite the fact that all the original source material had been exhausted by the end of the second series . The series has also achieved success outside the UK . In the United States, the first series' transmission on PBS in the autumn of 2012 drew an average audience of three million viewers . This figure was 50% higher than the network's primetime average for the 2011--12 season . </P> <P> In December 2015, BBC director general Tony Hall announced that the series had already been commissioned for a 2016 Christmas special and a sixth series, set to consist of eight episodes . The Christmas special was set in a missionary hospital in South Africa, and subsequent episodes would see the characters adapting after their return to Poplar as they move into 1962 . In November 2016, the BBC announced it has commissioned three further series and Christmas specials, through to a ninth series in 2020, moving the plot into the mid-sixties . As of 12 March 2017, 51 episodes of Call the Midwife have aired, concluding the sixth series . </P> <Table> <Tr> <Th_colspan="2"> Series </Th> <Th_colspan="2"> Episodes </Th> <Th_colspan="2"> Originally aired </Th> <Th> Ave . UK viewers (millions) </Th> </Tr> <Tr> <Th> First aired </Th> <Th> Last aired </Th> </Tr> <Tr> <Td> </Td> <Td_colspan="1"> 1 </Td> <Td_colspan="2"> 6 </Td> <Td_colspan="1"> 15 January 2012 (2012 - 01 - 15) </Td> <Td> 19 February 2012 (2012 - 02 - 19) </Td> <Td> 10.61 </Td> </Tr> <Tr> <Td> </Td> <Td_colspan="1"> 2 </Td> <Td_colspan="2"> 8 (+ 1) </Td> <Td_colspan="1"> 25 December 2012 (special) 20 January 2013 (2013 - 01 - 20) </Td> <Td> 10 March 2013 (2013 - 03 - 10) </Td> <Td> 10.47 </Td> </Tr> <Tr> <Td> </Td> <Td_colspan="1"> 3 </Td> <Td_colspan="2"> 8 (+ 1) </Td> <Td_colspan="1"> 25 December 2013 (special) 19 January 2014 (2014 - 01 - 19) </Td> <Td> 9 March 2014 (2014 - 03 - 09) </Td> <Td> 10.54 </Td> </Tr> <Tr> <Td> </Td> <Td_colspan="1"> 4 </Td> <Td_colspan="2"> 8 (+ 1) </Td> <Td_colspan="1"> 25 December 2014 (special) 18 January 2015 (2015 - 01 - 18) </Td> <Td> 8 March 2015 (2015 - 03 - 08) </Td> <Td> 10.82 </Td> </Tr> <Tr> <Td> </Td> <Td_colspan="1"> 5 </Td> <Td_colspan="2"> 8 (+ 1) </Td> <Td_colspan="1"> 25 December 2015 (special) 17 January 2016 (2016 - 01 - 17) </Td> <Td> 6 March 2016 (2016 - 03 - 06) </Td> <Td> 10.54 </Td> </Tr> <Tr> <Td> </Td> <Td_colspan="1"> 6 </Td> <Td_colspan="2"> 8 (+ 1) </Td> <Td_colspan="1"> 25 December 2016 (special) 22 January 2017 (2017 - 01 - 22) </Td> <Td> 12 March 2017 (2017 - 03 - 12) </Td> <Td> 10.75 </Td> </Tr> </Table>

Call of the midwife season 3 episode 1