Photo/IllutrationThe Osaka District Court in Osaka’s Kita Ward, which hears a case over the use of a balance ball by a pregnant woman during labor. (Sotaro Hata)

OSAKA--A couple whose baby was born with cerebral palsy and died before turning 2 are suing a maternity clinic here for instructing the mother to use a balance ball during labor, which she fell off.

The parents say the fall caused their baby’s disability and premature death, and are seeking 90 million yen ($803,070) in damages in a lawsuit filed against the clinic and one of its doctors at the Osaka District Court.

In the first hearing of the case on Oct. 24, representatives for the clinic in Osaka’s Higashi-Yodogawa Ward and the doctor said they would fight the action.

The plaintiffs are both in their 30s and now live in Yamanashi Prefecture.

Balance balls, also known as exercise balls or labor balls, are made of soft elastic and filled with air. They are used for physical therapy and exercise, and at some maternity clinics and maternity centers in Japan to help ease labor pain, according to health-care workers in maternity service.

Court documents showed that the woman checked into the clinic in June 2013 after her waters broke.

She put her upper body on a balance ball placed on her bed, but lost her balance and toppled over, according to the documents.

When her doctor performed a cesarean operation, the woman was told her uterus had ruptured.

The couple’s son was born in a near-death state and inflicted with cerebral palsy.

The infant died when he was 19 months old.

The plaintiffs argued that rupture of uterus was caused by the mother’s fall when she was told to use the balance ball.

They said that the clinic suddenly instructed her to use an exercise ball, that she had never touched a balance ball prior to that, and that no nurse was available at the time to assist her.

The couple maintained that they had both developed psychiatric disorders and experienced mental anguish resulting from medical malpractice and caring for their baby with the disorder.

The Japan Council for Quality Health Care, a third party organization that examines medical accidents in the public interest, said in a report on the couple’s case, “although there is the possibility that her uterus was ruptured due to the impact from (the mother’s) fall, it is difficult to conclusively determine the cause.”

But the report also stated that "it is desired that health care workers should fully explain how to use a balance ball and pay full attention to the user’s safety."

The father said he is hoping to “get to the bottom of why our son had to die.”

A lawyer representing the clinic and the doctor declined to comment on the case.