In about a month Rebecca Lingafelter and fellow Third Rail Repertory company member Mark Valadez will welcome their first child, a girl, into the universe.

In a masterstroke of precisely charted career planning that should be the envy of every arts professional, Lingafelter is directing "Lungs," a play about a couple debating having their first child.

Darius Pierce and Cristi Miles portray an on-stage twosome working through their parental concerns in the show that opens Aug. 4 at the CoHo Theater.

And, actually, credit for the arrival of "Lungs" probably goes to kismet, not calculation.

"Darius has had this piece in his dream chest for six years," says Lingafelter. "He looked at doing it various places, and then this year we did a reading of it and it just seemed to resonate in a particular way with the company."

Duncan Macmillan's 2011 two-hander couches the question of having a baby within questions around environmental impact and climate change.

"We read the play right after Trump pulled out of the Paris Climate Accord, so I think there's a special kind of political resonance in some of the environmental conversations that happen in the play that shout, 'OK, this really is the right time to do this show,'" Lingafelter says.

If your Netflix queue is backed up with "Gasland," "No Impact Man," and other apocalyptic eco-content, the thought of actors wagging their fingers at each other about fossil fuel consumption might not appeal as an evening out.

"Lungs" takes a different approach.

"It is absolutely a love story," says Lingafelter. "One of the things that I think is really delightful about the play is that there is this quality in the writing of a romantic comedy. It's a little bit boy-meets-girl, boy-looses-girl, boy-gets-girl-back scenario."

But Macmillan isn't afraid to dig into the serious, essential questions, Lingafelter says: "Is it my biological imperative to have children? Or am I responsible to these greater questions around the survival of the species and the planet?"

The play and the pregnancy cap a stellar year for Lingafelter, who co-produced and starred in "db" for CoHo Productions and co-directed "The Angry Brigade" for Third Rail. When Third Rail Managing Artistic Director Maureen Porter asked her to direct "Lungs," Lingafelter wasn't sure she wanted to go there.

"I was like, 'You know, there are already so many wonderful emotional ups and downs of this process, is that something I want to bring into a professional room?'" she says. "I think I make art because I'm drawn to things that tend to speak to my experience and that I hope will translate to other people's experience - so I said 'Yes.'"

Lingafelter's husband is crafting the sound design for the production. Conversations from home are mirrored in the play, she says, resulting in looks to each other during rehearsals.

"There's one moment in the play that I think many new parents of the 21st century recognize: When 'W' (Miles) says to 'M' (Pierce), 'Why do we refer to the size of the baby with food? 'This week your baby is the size of lentil. This week your baby is the size of an olive,'" says Lingafelter, laughing.

She and Valadez check a phone app that charts their baby's growth. "And we have a bunch of books, and all of them refer to the size of the baby in terms of food," she says. "Sometimes it's not even things that are person-shaped. We had one a few weeks ago that was the size of a kale. I don't even know what that means! What size is kale?"

You might expect the heightened environmental concerns of the on-stage characters -- we're talking to the ozone layer and back -- to intensify anxieties for the expectant parents behind the scenes. Luckily, no.

"I feel like the play has made me more conscious rather than worried," Lingafelter says. "I am bringing a person into the world who's going to have an impact and what are the ways in which I'm just thinking consciously about that."

"I think that's one of the challenges about talking about climate change -- there are all of these statistics and hundred-year scenarios and it feels a little intangible," she adds. "There's been a lot of talk, actually, in the arts about how can we bring these messages to people in a way that they feel connected to them? I feel that this play does that. These are complicated, normal people going through this and thinking about this. I hope that in the way that it swayed my consciousness it would do that with an audience, too."

-- Lee Williams for The Oregonian/OregonLive

"Lungs"

Where: CoHo Theater, 2257 N.W. Raleigh St.

When: 7:30 p.m. Thursday-Saturday and 2 p.m. Sunday, Aug. 4-26,

Tickets: $25-$45, www.thirdrailrep.org, 503-235-1101