By Alina Selyukh
WASHINGTON (Reuters) - A record number of women will serve in the U.S. Senate and House of Representatives after sweeping victories in Tuesday's election that challenged the traditional male makeup of the U.S. legislative branch.
Twenty women will serve in the 100-member Senate and at least 81 of the 435 members of the House of Representatives will be women. A few races still await final results from Tuesday's voting.
Female representation in Congress has now been increased tenfold in the past two decades, according to Emily's List, a liberal political group.
For several states, women won Senate seats for the first time, including in close races in Massachusetts, where Democrat Elizabeth Warren defeated Republican incumbent Scott Brown; in Nebraska, where Republican Deb Fischer upset former Democratic Senator Bob Kerrey; and in Wisconsin, where another Democrat Tammy Baldwin also became the first openly gay senator.
A number of congressional districts will also be represented by women for the first time.
In another first, three women Democrats - Governor-elect Maggie Hassan and Representatives-elect Carol Shea-Porter and Annie Kuster - made New Hampshire the first state to vote for an all-female congressional delegation and governor, according to Emily's List.
"This election provided a clear choice between those who want to move forward and those who would turn back the clock to deny women equal pay and access to preventive health services and birth control," said a statement from the group.
While the main policy theme of the presidential election was the poor state of the U.S. economy, issues that predominantly affect women - contraception, abortion, rape and others - often came to the forefront in the White House and congressional contests.
Some of the most memorable gaffes of the 2012 races involved male politicians talking about women's health and abortion.
Missouri Republican Todd Akin, who had been a favorite to unseat Democratic Senator Claire McCaskill, is seen as having sabotaged his campaign with a comment that women had biological defenses against pregnancy in cases of "legitimate rape." He lost on Tuesday.
Similarly, Illinois Republican Joe Walsh lost a House seat to Democrat Tammy Duckworth after saying that abortion was never necessary to save a woman's life. Indiana Republican Richard Mourdock lost his bid for a Senate seat to Democrat Joe Donnelly after saying that a pregnancy resulting from rape was "something God intended to happen."
Nearly twice as many women as men rank social issues, such as abortion and same-sex marriage, as most important for their vote, according to Reuters/Ipsos polling data.
The data showed those views as well as high turnout among women also helped President Barack Obama to defeat Republican challenger Mitt Romney.
Democrats denounced Romney for shifting positions on abortion and contraceptive rights since his 2002 election as governor of Democratic-leaning Massachusetts and for failing to support Obama-backed legislation which guarantees equal pay for women.
(Editing by Alistair Bell and Christopher Wilson)