(CNN) -- A Nigerian immigrant is responsible for paying child support for twins conceived through in vitro fertilization with his wife -- even though the procedure took place at least a year after the couple had separated, Massachusetts' highest appeals court has ruled.
The court said Tuesday that because the husband, Chukwudera B. Okoli, had originally consented to the artificial insemination procedure, he is now responsible for the payments as the twins' legal and biological parent, according to court documents.
Okoli had argued that the agreement should be void because he had consented under duress.
He said his ex-wife, Blessing, threatened to obstruct his U.S. citizenship application if he did not consent, the documents said.
The two were married in Boston in 1991 and tried unsuccessfully to have children. They were eventually placed on a waiting list for donor eggs to pair with sperm that Okoli had donated.
Though they separated in 2000, donor eggs became available in November of the following year. Blessing Okoli then acquired the husband's consent to begin the in vitro procedure at a fertility clinic in Boston.
Their twins were born May 12, 2003.
Court documents did not indicate Okoli's current immigration status.