A fetus borne by a policyholder involved in a car accident is eligible for coverage under a type of casualty insurance policy, the Supreme Court ruled Tuesday, upholding a high court decision that ordered an insurer to pay damages over a 1999 accident.

The decision by the court's No. 3 petty bench concerns a type of policy that offers coverage for damage and injuries resulting from an accident involving the policyholder with a car that has no other coverage than the compulsory automobile liability policy, which offers limited compensation.

The 1999 accident, which occurred in Toyama Prefecture, involved a car carrying a man and his pregnant wife colliding with a lightly insured vehicle.

The wife gave birth to a boy at the hospital she was taken to after the accident, but her son was left with severe limb disabilities.

The injured parties filed a claim with Mitsui Sumitomo Insurance Co., which rejected payment for damage to the fetus, saying the policy's provisions limit coverage to policyholders and their relatives, not a fetus.

But on Tuesday, the Supreme Court cited the Civil Code's Article 721, which effectively deems a fetus as already born as far as claims for casualty insurance are concerned, and acknowledged the boy may claim compensation.

The top court thus let stand the Nagoya High Court's ruling last May ordering the insurer to pay around 135 million yen to the boy.

While the top court's decision concerns a particular type of insurance policy, experts say other casualty policies may also be affected by the ruling.