After asking for some time off in September 2004 to complete the procedure, the lifelong Catholic gave her boss an update about a month later: She was pregnant.
But only days after that, she said, she got a pink slip from the Catholic school system. Administrators, according to her lawyer James C. Jones, claimed Romenesko violated a provision of her employment contract saying a teacher has to act in accordance with Catholic doctrine.
"All she was trying to do was have a child, which of course should be a wonderful thing," Jones said Tuesday.
In vitro fertilization involves extracting eggs from a woman's ovaries and fertilizing them with sperm in a laboratory dish or test tube. The fertilized eggs are implanted into the woman's uterus.
Catholic teaching holds that the procedure is morally wrong because it replaces the "natural" conjugal union between husband and wife and often results in destruction of embryos.
Even though Jones said the couple used their own eggs and sperm and none of the embryos were destroyed in the process, the church forbids such donations and condemns all forms of experimentation on human embryos.
Romenesko, 37, filed a discrimination complaint against Appleton Catholic Educational System, Inc./Xavier, which runs seven Catholic schools in Appleton, about 100 miles north of Milwaukee.
An investigator from the Equal Rights Division of the state Department of Workforce Development upheld the firing in December and Romenesko appealed. A hearing was set for Friday but was postponed, probably until September, Jones said.
"I believe that discrimination occurred," Jones said, contending school officials knew for a month before the firing that she had undergone the procedure. "It was only after she was pregnant that she was terminated."
If the administrative law judge sides with Romenesko, the state could award payment for back wages, benefits, attorneys' fees and other expenses, Jones said.
School district president Tony Abts referred inquiries to lawyer Gregory Gill Sr., who didn't immediately return a call Wednesday. Diocese spokesman Tony Kuick did not return calls seeking comment.
Romenesko, reached by phone Tuesday night, said others in the school system, including a board member, had children through the procedure without repercussions.
Romenesko tells her story on a Web site, complete with pictures of her twin girls, Alexandria and Allison, born in March 2005, 2 1/2 months premature.
"They're just doing superb. It's a miracle," she said.
The in vitro fertilization issue was first highlighted for Catholics in "Donum Vitae," a 1987 church instruction written by the cabinet of Cardinal Joseph Ratzinger, now Pope Benedict XVI, on "respect for human life in its origin and the dignity of procreation."
Mark Johnson, who teaches moral theology at Marquette University in Milwaukee, said the 1987 document was the first serious official church writing on the subject, and modifications could be possible.
"This is brand spanking new stuff in the life of a church that is 2,000 years old," Johnson said, noting that the Vatican now is considering allowing the use of condoms to help battle AIDS in Africa despite its longtime opposition to contraceptive devices.
Romenesko said she now attends Lutheran services and holds a part-time job unrelated to teaching. She lives in Darboy, near Appleton, with her husband, Eric, and the girls.
On her Web site, she said she wanted to make her story public for the sake of her children and others born through the procedure.
"I want them to know that just because their parents had them through in vitro fertilization, that we are not evil sinners," she wrote.