The Supreme Court has decided to uphold lower court rulings that a Civil Code clause allowing only husbands to disavow paternity of their wives’ children does not violate the Constitution’s guarantee of gender equality.

The top court’s Second Petty Bench dismissed the appeal in a unanimous decision by the four justices, with the final judgement on the case dated Wednesday. The court did not make a constitutional judgment.

The Civil Code allows husbands to file a disavowal of their paternity within a year of learning about the birth of the child. The law also has a clause stipulating that children conceived by women during marriage are assumed to be the offspring of their mothers’ husbands.

In August 2018, the Osaka High Court found the clause allowing only husbands to disavow paternity to be constitutional, upholding a Kobe District Court ruling in November 2017.

The high court said that wives are not parties to father-child relationships, while husbands have a direct interest in denying paternity because they would be exempted from child support duty and be able to exclude the child from their heirs.

The court also said that provisions related to presumption of paternity are designed to swiftly settle the father-child relationship status.

It would not be irrational to give wives and children the right to legally disavow paternity, but such a change is a matter that should be handled by the Diet, the court also said.

The top court made the decision in a lawsuit filed by a woman who separated from her abusive then husband and gave birth to a daughter with another man in 1983 before she divorced.

Not wanting her former husband to know of the child, the woman did not submit a birth certificate for the daughter. As a result, the daughter and her two children were not recognized under the Japanese family registration system until 2016.

The suit was filed after it was found that many citizens remained unregistered under the system for similar reasons.

In July 2019, a Justice Ministry study group released a report that children and wives should be given the right to deny paternity. A subgroup of the Legislative Council, which advises the justice minister, is discussing the matter.