A British woman is 14 weeks pregnant after conceiving the country's first baby guaranteed to be free of a hereditary breast cancer, doctors have revealed.
The unidentified woman and her husband underwent in vitro fertilization to screen 11 embryos for the presence of one gene, BRCA-1.
The woman is now 14 weeks pregnant with her first child.
Women who carry either the BRCA-1 or BRCA-2 gene have a 50 to 80 percent chance of developing breast cancer.
The 27-year-old woman and her 28-year-old husband, who remain anonymous, decided to go through the invasive in vitro fertilization procedure in order to produce embryos that could be genetically screened.
The couple, who are fertile, decided to screen embryos using the technique called preimplantation diagnosis because the husband had tested positive for the gene, and his grandmother, mother, sister and cousin had all suffered breast cancer.
"For the past three generations, every single woman in my husband's family has had breast cancer, as early as 27 and 29," the woman told British media.
"I thought this was something I had to try because, if we had a daughter with the gene and she was ill, I couldn't look her in the face and say I didn't try."
Five of the 11 embryos conceived in the lab were free of the gene. One of the two implanted in the woman became a viable fetus.
Two healthy embryos have also been frozen for future use.
"Women now have the option of having this treatment to avoid the potentially guilty feeling of passing on this genetic abnormality to a child. This gives us the chance to eradicate this problem in families," said the couple's doctor, Paul Serhal, medical director of the Assisted Conception Unit at University College London Hospital.
"Women now have the option of having this treatment to avoid the potentially guilty feeling of passing on this genetic abnormality to a child. This gives us the chance to eradicate this problem in families," he said.
Only one other woman, an Israeli mother-to-be, is believed to have conceived after undergoing the screening process.
But critics are saying it's not morally acceptable to destroy viable embryos because they carry a gene that may cause cancer.
And some ethicists are expressing concern that screening embryos for undesirable genes may lead to "designer babies" who are created for their looks or smarts.
"What we are saying is that we don't just accept any children we happen to conceive we want to choose them," said McGill University Professor and medical ethicist Margaret Somerville.
The technique itself was actually developed 15 years ago and several clinics have been doing it for years in Canada.
But doctors normally screen for genetic diseases like cystic fibrosis. Not for the potential of developing illnesses such as breast cancer.
Doctors point that there are no guarantees. Despite the high incidence of cancer among women who carry the BRCA-1 and BRCA-2 genes, they account for only five per cent of all breast cancers.
"You are testing for a disease which may or may not occur in a child," Dr. Simon Phillips said.
Having a certain gene just means an increased risk of having cancer.
Laurence Shaw, deputy medical director of the Bridge Fertility Centre in London, described the technique as "an exciting development."
"It opens the door to a lot of questions about screening of diseases that might happen in the future," he told the Press Association.
"However we should be aware that this does not mean that the baby born will be immune from breast cancer - it means that the baby with that gene has a decreased likelihood of having that cancer."
