For Bibi and Henry, it was love at first sight when they moved into a new home and began their future together last summer. For their baby, the first Nile hippo born at the Cincinnati Zoo & Botanical Garden in 75 years, the future is uncertain.

Seventeen-year-old hippo Bibi gave birth to the female calf Tuesday morning, six weeks earlier than expected. Because she is unable to stand and nurse from her mother, she is under round-the-clock critical care by zoo staff.

“We are giving her fluids and keeping her moist and warm,” Christina Gorsuch, curator of mammals at the Cincinnati Zoo, said in a news release. “Her little system is underdeveloped, and getting her to a healthy weight will be a challenge. Vets and animal staff are doing everything they can to get her through this critical time.”

The calf is extremely small: She weighs only 29 pounds, much lower than the range of recorded birth weights for her species, which is 55-120 pounds.

"Her heart and lungs sound good and she is pretty responsive to stimuli, but we aren’t sure how developed her muscles and brain are." Gorsuch said.

Zoo scientists had captured an image of the baby in utero via the first ultrasound ever done on a Nile hippo earlier this month.

On Monday, after Bibi showed signs of labor, zoo staff did another ultrasound to confirm that the baby was coming. They also collected milk from Bibi, which they hope they can get the baby to drink. They'll continue that process until the calf can stand on her own and be reunited with her mother.

The zoo will post updates about the baby's condition on its Facebook page.