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Highlights from the FDA Report on Cloning

A new report from the FDA concludes that meat or milk from cloned animals is just as safe to consume as that from traditionally conceived animals.

The report does contain some caveats, but these relate to health risks faced by the clones, not risks to people eating meat from them.

For instance, some species of cloned livestock do face a higher risk of birth defects, sometimes fatal, such as being born abnormally large or having health problems in the first few months of life. But the report says safeguards already exist to prevent sick animals from entering our food supply.

Also, the FDA didn't weigh in on whether clones on average have a shorter lifespan, saying the technology has existed only for a relatively short time.

Here, highlights from the FDA report:

Safety of Meat, Milk from Cattle, Goats and Pigs

Food products from juvenile and adult cattle, goats and pigs are "virtually indistinguishable" from their noncloned counterparts and their consumption poses no additional risk, says the FDA.

Safety of Meat from Sheep

FDA scientists said they didn't have enough information to rule on the safety of meat from cloned sheep.

Health Risks to the Cloned Animals

Calf and lamb clones have a higher risk of death in the last weeks of pregnancy and the first few weeks after birth. Complications include respiratory problems, enlarged umbilical cord, hyper/hypothermia and abnormal development of major organs.

Cattle clones continue to be at an increased risk of death up to six months of age, but those that survive often outgrow their health problems and appear to be healthy into adulthood.

Pig and goat clones do not appear to be at increased risk for health problems in the final stages of pregnancy or in the first few months of life.

Health Risks to the Offspring of Cloned Animals

The FDA says the offspring of animal clones appear to be normal and healthy.

Most of the problems causing fatal birth defects or sick clones are related to the initial creation of the clone in the lab, before it's implanted into a surrogate animal. Clones are essentially created by inserting the genes of the donor animal into an egg cell that has had its nucleus removed. That embryo is then implanted into a surrogate female.

The embryo may fail to develop properly before it's implanted or the embryo may not implant properly, leading to miscarriages, death of the fetus in the womb, or other potentially fatal or crippling complications.

But since the offspring of cloned animals are conceived sexually, they're not at risk from development problems due to the cloning procedure.

Health Risks to the Surrogate Mothers

Cows and ewes implanted with cloned embryos are at an increased risk of health problems during pregnancy and delivery. Problems include abnormal development of the placenta and complications due to the sometimes abnormally large size of the fetus.

Surrogate swine and goat dams bearing clones do not appear to be at increased risk of complications during pregnancy.

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Vikki Valentine
Vikki Valentine is a senior supervising editor on NPR's science desk. She oversees the network's health coverage across broadcast and digital platforms. Previously, Valentine was the network's climate change, energy, and environment editor and in this role was a recipient of a 2012 DuPont Award for coverage of natural gas drilling in Pennsylvania.