Conservative groups have expressed dismay at news that US Vice-President Dick Cheney's lesbian daughter is pregnant.
Mary Cheney, left, is expecting a baby in spring 2007
Mary Cheney, 37, and partner Heather Poe are expecting a baby in late spring 2007, the vice president's office said.
Concerned Women for America said the pregnancy was "unconscionable".
Meanwhile, a gay-rights group said Mr Cheney faced "a lifetime of sleepless nights" for serving in a White House opposed to same-sex marriage.
Correspondents say that Mary Cheney's openness about her sexual orientation has for years posed a dilemma for conservative activists who admire Dick Cheney's stance on many issues, but consider homosexuality a sin.
The CWA's Janice Crouse told the Associated Press news agency: "It's very disappointing that a celebrity couple like this would deliberately bring into the world a child that will never have a father.
"They are encouraging people who don't have the advantages they have."
The vice president's office has declined to elaborate on the circumstances of Mary Cheney's pregnancy.
The vice-president has opposed a federal ban on gay marriage
"The vice president and Mrs. Cheney are looking forward with eager anticipation" to the arrival of their sixth grandchild, a spokeswoman said.
Mary Cheney has been with her partner for about 15 years.
She was an aide to her father during the 2004 election campaign, and now is vice-president for consumer advocacy at AOL.
News of her pregnancy was welcomed by Joe Solmonese, president of gay rights group the Human Rights Campaign.
"Mary and Heather's decision to have a child is an example that families in America come in all different shapes and sizes," he was quoted as saying by AP.
"The bottom line is that a family is made up of love and commitment."
But Jennifer Chrisler, executive director of gay advocacy group Family Pride, said: "Grandfather Cheney will no doubt face a lifetime of sleepless nights as he reflects on the irreparable harm he and his administration have done to the millions of American gay and lesbian parents and their children."