The dolphin's ultrasound has the Shedd staff feeling a bit like nervous grandparents..
"It's full grown now. We can actually see the heartbeat, so we know the calf is healthy. We know that mom is healthy," said Ken Ramirez, executive vice president, Shedd Aquarium.
Mom is Tique, one of only a few Pacific White-sided dolphins in an aquarium in North America. She's smart and full of personality. And she's due at any moment.
"She's a great animal and we kind of put it in her hands and instinct to kick in," said Jessica Whiton, senior trainer.
The mother-to-be is being watched around the clock and the staff is meticulously tracking any changes in respiration, swimming patterns or eating habits, anything suggesting that labor is imminent. One tell-tale sign is an arching and crunching behavior that is similar to contractions.
"The mom is sort of flexing her body, helping the calf come out," said Ramirez.
"When we see an increase in frequency of the crunches and arches, that could be one of the indicators that the birth is soon," said Maris Muzzy, cetacean manager, Shedd Aquarium.
If all goes well, the birth will happen naturally with no inducing or help from humans.
"We train really hard to be ready to intervene in any possible emergency, but what you hope is that everything goes so well that you get to sit back, watch, and enjoy the miracle of birth," said Ramirez.
The calf was conceived naturally, and the father is currently at an aquarium in Florida. The male is typically not involved in raising the calf. The mother does it on her own.
Thursday is actually Tique's due date but just like with human pregnancies, it's not an exact science. So for now, the staff waits, some with sleeping bags under their desks n case it's a long labor.
From the ultrasound, the sex of the calf is unclear and Tique's not telling.