WHAT TO EXPECT WHEN YOU’RE EXPECTING: Leigh Mallonee (left) and Megan Slater prepare for a new addition in the Philadelphia Theatre Workshop’s production of “Incoming,” through April 29 at the Walnut Street Theatre Studio 5, Ninth and Market streets.

When out New Jersey playwright Kathy Anderson overheard a lesbian acquaintance tell a story about ordering donor sperm over the Internet, it planted the seed of an idea in her head.

“It just got lodged in my subconscious,” Anderson said.

That idea slowly developed into “Incoming,” presented through April 29 by the Philadelphia Theatre Workshop at The Walnut Street Theatre Studio 5, Ninth and Market streets.

Anderson’s play revolves around Liz and Sally, a long-term couple whose relationship turns upside down when Sally decides to get pregnant.

The comic fantasy explores ideas about parenthood, family and the struggle to sever emotional baggage from the past.

“I see the world through lesbian eyes, so I think that influences what I write,” Anderson said of the impact of her sexual orientation on her writing. “I’ve seen a lot of changes in lesbian life over the years. Today, it’s not the central thing in people’s lives — there’s a much more open feeling.”

Anderson’s play was part of the Philadelphia Theatre Workshop’s Playshops program, which allows new playwrights to work with seasoned professionals to develop their plays through private readings, audience feedback and directorial guidance.

“It’s been great watching this play grow,” said out director Robin Eisenberg, co-founder of the Philadelphia Theatre Workshop. “When we first saw the draft, it was clear that Kathy was a talented writer with a great ear for dialogue. But through the Playshops program, we’ve been able to add more focus to the story and strengthen the characters.”

“It was an incredible, life-changing experience,” Anderson said. “Robin has been very nurturing and giving and helpful in shaping this play. Every new playwright should get this experience. I’ve gotten more confidence through this process in a very comfortable, safe environment.”

Anderson said that seeing her ideas go from paper to the stage was highly rewarding.

“This is a play that’s not just about people standing around and talking,” she said.

But Anderson’s highly physical ideas required some innovative solutions from Eisenberg and the stage crew.

“In the play, one of the characters who is nine months pregnant straps herself to an inversion table and turns upside down in an attempt to stall for time,” Eisenberg said. “Kathy had never seen an inversion table, but she had this image in her mind about the most horrifying thing you could do to a woman who’s nine months pregnant. And while this is all hysterically funny on the page, we had to come up with ways to give the audience something visually. It was a matter of finding the balance between what had to be physically real and what was surreal. But it was a really fun challenge.”

Eisenberg said she was also excited to work on a play about relatable lesbian characters.

“‘Incoming’ is a play about women on the verge of self-discovery, a story featuring lesbian characters that don’t die, break up or become straight,” she said.

“I think it’s great that Philadelphia gets to see lesbians who are real people struggling with real issues. People will really be able to find themselves on this stage. In my mind, ‘Incoming’ fulfills a lot of our mission as a theater company, which is to show a full spectrum of sexual orientations, and to represent gay and lesbian characters as being very human and a part of the mainstream.”

Anderson said she’d like the audience to walk away pensive but very amused.

“It’s a thought-provoking story, but I just want them to have fun,” she said. “The world is in such a state these days, and if someone can have a few minutes of laughter and leave thinking about things a little differently, I’d be very happy.”

Half of all ticket proceeds from the April 19 performance will go to the Delaware Valley Legacy Fund, a group that allots philanthropic funding to various GLBT organizations.

“It’s an effort on our behalf to connect with the community and an effort on DVLF’s part to engage women in philanthropy,” Eisenberg said.

“Incoming” will also be presented as part of the International Centre for Women Playwrights’ “Her-rah!” event June in Chicago.

For tickets and information, see www.philadelphiatheatreworkshop.org.