LONDONThe second series of Brit drama “Call the Midwife” will bow on PBS in March, following a deal between BBC Worldwide America and PBS. The first of six episodes will air March 31 at 8 p.m. ET. Season one was a strong performer for PBS winning 3 million viewers, 50% above PBS’ primetime average for the 2011-12 season, according to the BBC. Season two of “Midwife” will be followed on PBS by ITV Studios’ “Mr Selfridge” in the Masterpiece slot. “Midwife,” written by Heidi Thomas and helmed by Philippa Lowthorpe, was the highest-rated BBC drama launch on record when it bowed in January.