Annie Lööf, 31, has announced that she is having a baby with her husband Carl-Johan Lööf and is set to take six months of parental leave.
But she has said that she will still do "certain things that party leaders do during that time" such as making a Christmas speech.
The Centre Party has said that Anders W. Jonsson, an MP and former doctor in his fifties, will take over most of her duties including party leadership debates.
In Sweden, parents are entitled to 480 days of paid parental leave and her long term partner, whom she married in 2011 is also expected to take several months off work.
Lööf has made no secret of her desire to become a parent.
In an interview with Swedish newspaper Aftonbladet in 2012 she said: "Someone asked what title I was hoping for after 2014 [an election year in Sweden] and I answered 'mum'. It would be great".
Lööf became MP for Jönköping County in southern Sweden when she was just 23 years old. She followed her father Hans-Göran Johansson’s footsteps into politics; he is also a Centre Party politician and is the current mayor of Värnamo Municipality. Lööf was selected to become leader of the party in 2011 and was Minister for Enterprise in the Alliance government. She has a degree in law and lives in Nacka, Stockholm, with her husband.
Writing about her news in more detail on Facebook, Lööf said: "It's amazing. I have been feeling good so far, so we hope it continues. Our plan is to share the parental leave."
Asked if her time away from her daily duties could have an impact on her party, the leader's press secretary Oscar Sundesvall told Swedish public broadcaster SVT: "Annie Lööf is perceived as very trustworthy even outside the party and she is the face of the party. It wouldn't be wrong for more [Centre Party] people to be seen by the Swedish people."
The Centre Party has rural roots, emerging from Sweden’s Farmers' League, which was set up more than one hundred years ago. Agricultural and environmental issues remain key concerns alongside allowing local communities to make their own decisions. More recently the party has tried to attract urban voters by promising help for small businesses.
Lööf is not the only party leader who is expecting. Ebba Busch Thor, 28, the new head of the Christian Democrats, the smallest party in the Alliance, is set to have a baby in May.
Busch Thor recently told Swedish newspaper Expressen in March that her husband, Niklas Thor, a football player for IK Sirius FK, would claim the major part of their parental leave. She said she would like to go on leave for "a shorter period" this summer.
Sweden has four female party leaders in government. Anna Kinberg Batra took over from former Prime Minister Fredrik Reinfeldt at the helm of the Moderates earlier this year and Åsa Romsen is co-spokesperson for the Greens.
Gudrun Schyman leads the Feminist Initiative, which just missed out on its first seat in parliament in Sweden's last general election in September 2014.