NEW YORK (Reuters) - A white woman who gave birth to two children - one white and one black - after becoming pregnant through in-vitro fertilisation is now suing the doctors who performed the test-tube procedure, her lawyer said on Tuesday. Donna and Richard Fasano, who have agreed to give up the black child if DNA tests confirm the identity of his biological parents, filed a negligence and medical malpractice suit on Monday in New York State Supreme Court. They accuse three physicians of causing "severe pain, discomfort, disability and mental and emotional shock" as a result of their "failing to properly handle, store and perform embryo transfer." Named in the suit were Lillian Nash, Dov Goldstein, who owns the fertility clinic, and John Obasaju, an embryologist, and also the Brooklyn Fertility Centre and Central Park Medical Services. On April 24, 1998, Fasano was implanted with a number of embryos created by fertilising her eggs with the sperm of her husband in Nash`s office. That same day Nash, an obstetrician-gynecologist, also performed in-vitro fertilisation (IVF) for Deborah Perry-Rogers, a black woman, the lawyer said. Fasano was implanted with a number of her own embryos, as is usual in IVF, and apparently with at least three embryos from Rogers and her husband Robert Rogers. "Four weeks later, Dr. Nash advised my client she was pregnant and two weeks after that the doctor informed both couples of the mistake," Cohen said. Rogers did not conceive. Fasano did, and the boys were born on Dec. 29, 1998. The Rogers filed a civil suit against the doctors last week over the mix-up and also sued the Fasanos to determine genetically the identity of the black child. Cohen said. "If they(the Roberts) are the biological parents, custody of the black child will be turned over to them and visitation rights will be worked out for the Fasanos," he

said. IVF, known commonly as test-tube fertilisation, has become more common since it was perfected in the late 1970s. Doctors take a woman`s egg, sperm from a man, and mix them in a dish. Any resulting embryos can be frozen or implanted directly in the woman`s womb, or into the womb of a surrogate mother. New York State Health Department spokeswoman Frances Tarlton said the Fasano case was the state`s first known embryo mix-up.