Voting in the by-elections went relatively smoothly
Kenya's coalition partners have remained on roughly level terms after by-elections in five constituencies.
Prime Minister Raila Odinga's Orange Democratic Movement (ODM) won three seats, while President Mwai Kibaki's Party of National Unity (PNU) won two.
The ODM lost one Nairobi seat to the PNU, and now has 103 parliamentary seats to the PNU's 104.
Kenya's coalition government was formed after disputed elections sparked weeks of political violence.
The coalition has been looking decidedly fragile and political analysts say the by-election results could have upset the delicate balance of power in parliament.
Supporters of Mr Kibaki and Mr Odinga have differed over several key areas, which include suggestions of granting an amnesty to youths arrested after the post-election violence.
Calls for reform
Despite a handful of incidents reported in one of the constituencies close to the border with Tanzania, Wednesday's polls seem to have gone relatively smoothly, the BBC's Karen Allen reports from the capital, Nairobi.
Even so, she says that calls for the reform of the discredited electoral commission are unlikely to go away.
ODM retained the seats of Emuhaya in the west and Ainamoi in the Rift Valley, but lost Embakasi in Nairobi to the PNU.
By-elections do not traditionally attract high numbers of voters, and there was a low turn-out in all the constituencies.
The battle for parliamentary dominance is far from over, following the deaths of two ODM MPs on Tuesday in a plane crash.
Roads Minister Kipkalya Kones and Assistant Home Affairs Minister Lorna Laboso were killed a day before the by-elections.
No date has been set for the election of their replacements.
Some 1,500 people died and more than 300,000 others were displaced in the violence that followed December's presidential poll.
Two of the seats being contested in the by-elections were left empty after the MPs were killed in the unrest.
The government has set up a number of commissions to investigate the violence.