An English Catholic bishop has denounced the first reported births of "three-parent" babies in the UK as "deeply concerning."

Auxiliary Bishop John Sherrington of Westminster said the creation of babies by mitochondrial donation treatment (MDT) was unethical because the process involved the destruction of two embryos to create a single new life.

His remarks came after The Guardian newspaper reported May 9 that "first U.K. baby with DNA from three people" was born after the new in vitro fertilization (IVF) procedure.

"It shows a further step in the technical manipulation of new life with the loss of human life as part of the technique," said Bishop Sherrington, lead prelate for life issues of the Bishops' Conference of England and Wales.

"The technique depends on the destruction of two human lives who had inherent dignity and rights and must be protected from their creation as persons in order to create a third embryo and life," he said in a May 11 statement published on the bishops' conference website.

"It also fractures the child from biological parenthood," he continued. "It steps into the unknown world of genetic engineering with manipulation of the human germline."

"The gift of life, to be respected and treated with dignity from conception to natural death, is a mystery which cannot be reduced to technical manipulation," the bishop added.

In 2015, the U.K. became the first country in the world to legalize the genetic modification of the human germ line in an attempt to fight inherited diseases.

It created a legal framework to permit two methods of mitochondrial transfer in the hope of curing illnesses such as muscular dystrophy.

Mitochondria are the biological power packs that give energy to nearly every cell of the body. If defective, cells can be starved of energy, causing muscle weakness, blindness, heart failure and death in extreme cases.

The procedures covered by the regulations include "three-parent" IVF by which material is extracted from an ovum and inserted into a donor egg before it is fertilized by the father's sperm.

The second technique, pronuclear transfer, involves up to four parents creating two embryos which are destroyed before the maternal embryo is cloned and repackaged with parts from the donated embryo.

Research on MDT is being pioneered in the U.K. by scientists at the Newcastle Fertility Center, which in 2018 became the first and only national center licensed to carry it out.

The Guardian used the Freedom of Information Act 2000 to ask how many children have been created by the technique.

It discovered that the Human Fertilization and Embryology Authority, the regulator, has permitted the creation of 30 babies by pronuclear transfer although "less than five" have been born. No details of the births were provided.

The Anscombe Bioethics Center, an Oxford-based institute serving the Catholic Church in the U.K. and Ireland, in a May 11 email to OSV News, explained that in creating each baby, two embryos were "functionally destroyed by the removal of their pronuclei and parts of both used to create a third embryonic human."

"This is the destruction of two embryonic human individuals to create a third individual," it said in its press statement.

"This is primarily unethical due to the destruction of two unique innocent human beings who had inherent dignity and rights. It is also unethical for two other reasons: the fracturing of biological parenthood, and the potential for serious unintended consequences."

Anscombe said that the technology carried "serious implications for the identity of the newly created baby, who will now have no right to identify information about her egg mother when they grow up."

The institute also questioned the safety of the technology, saying "it is a mistake to assume that the nucleus and the mitochondria have no deeper connection, and that the former can be transferred without any consequence."

It cited the findings of Paul Knoefler -- a researcher and professor of cell biology and human anatomy at the University of California, Davis -- that "there is strong evidence that the mitochondrial genome, for example, 'talks to' the nuclear genome, and has 'pervasive effects on cellular and organismal functioning.'"

Professor David Albert Jones, director of Anscombe, said: "Every child newly conceived is to be welcomed and we hope this new human life brings joy to his or her parents, but some ways of conceiving children involve risks or harms to the child."

"This is a new and unnecessary technique that does not add to the safety of IVF involving an egg donor, but adds further risks," Jones added.

"As with all IVF involving egg or sperm donors, this fractures parenthood and it is essential that the child is at least given identifying information about his or her egg donor parent. It is a fundamental human right to know about our biological origins."