A 63-year-old child psychiatrist who is set to become Britain's oldest mother defended her decision against accusations of selfishness on Thursday, saying her decision to bear another child was not made lightly.

"We're delighted with the pregnancy," Patricia Rashbrook, who is seven months pregnant, told reporters Thursday.

"We take our responsibility very seriously and regard the best interest of the child as paramount. What we would wish now is the right to pursue our family life in private."

Rashbrook, from Lewes, south of London, has two grown children from a previous marriage but recently remarried and underwent fertility treatment. She is due to give birth in two months.

When asked whether she was too old to have a child, she replied: "No comment."

Earlier, Rashbrook and her husband John Farrant, 61, issued a joint statement, saying: "We wish to emphasize that this has not been an endeavour undertaken lightly or without courage."

"A great deal of thought has been given to planning and providing for the child's present and future wellbeing, medically, socially and materially."

Controversial Italian fertility doctor, Severino Antinori, said he only treated Rashbrook in an unnamed former Soviet republic after she underwent strict medical examinations.

Antinori has told reporters that Rashbrook and her husband first visited him three years ago at his clinic in Rome, where he specializes in treating older women.

Details are sketchy but it's believed that Rashbrook was given the treatment last October and it was successful at the first attempt, using a single embryo.

Toronto doctor critical of decision

Dr. Cliff Librach, a reproductive specialist at Toronto's Sunnybrook Health Sciences Centre, said the birth triggers a "yuck" factor for most Canadians.

"Most people have kind of a 'yuck' factor about this, that she is just too old," he said. "A woman at that age having a seven year old at 70, it's just too much for most of us to really think it's the right thing to do."

He added that "I know of no fertility clinic anywhere across Canada that would ever consider getting a woman at 63 pregnant."

Antinori told Reuters that Rashbrook was "perfect" for the treatment, because although she was 62 at the time, she had a biological age of about 45.

He dismissed criticism that Rashbrook was too old to become a parent, telling the wire agency: "She should live for at least 20 to 25 years -- we are not giving birth to an orphan."

Antinori gained notoriety in 1994 when he helped a post-menopausal Italian woman in her early 60s give birth following fertility treatment with a donated egg.

He has said in the past he aimed to be the first to produce a baby cloned from an adult.

In 1997, Welsh woman Liz Buttle became Britain's oldest mother at the age of 60.

The oldest woman in the world to become a mother is believed to be 66-year-old Romanian Adriana Iliescu, who gave birth to a daughter last year after IVF treatment.

Rashbrook's pregnancy has sparked criticism from some conservative groups that oppose abortion and some types of assisted fertility treatment.

"It is extremely difficult for a child to have a mother who is as old as a grandmother would be," said Josephine Quintavalle, from the London-based Comment on Reproductive Ethics.

"It is just that consumer society that wants absolutely everything, and never stops to think that a child is not a product. She is being selfish and sometimes greater love is saying no."

James Healy of Britain's Human Fertilization and Embryology Authority, which regulates fertility treatment, told The Associated Press the law sets no age limit for treatment, which is "left to the clinical judgment of doctors."

"But the law says that clinics must take into account the welfare of the child, including the health, age and ability to provide for the needs of the child or children," he said.