Nadya Suleman gave birth to eight children on Jan. 26, including Nariyah, above. Suleman's fertility doctor, Michael Kamrava, is under investigation by a national medical society for what it believes was a breach of guidelines.

LOS ANGELES — A national medical society is investigating whether a fertility doctor followed its guidelines when he implanted six embryos into a Southern California woman who gave birth to octuplets last month.

The American Society for Reproductive Medicine confirmed Tuesday that it's investigating because Nadya Suleman says she received in-vitro fertilization for all 14 of her children at the same Beverly Hills fertility clinic.

Suleman, 33, told NBC's "Today" show that she was implanted with six embryos in each of her six pregnancies, resulting in four single births, a set of twins and the octuplets. No more than three embryos are considered the norm for a woman her age, and fertility experts and medical ethicists have been critical of the Jan. 26 birth of the octuplets.

The society has contacted Suleman and her doctor, and is prepared to assist the Medical Board of California, which is also looking into the pregnancy, the society's president, Dr. R. Dale McClure, said in a statement.

"Our guidelines provide the flexibility to give each patient treatment individualized to her needs, and her best chance to become pregnant without risking high-order multiple pregnancy," said McClure. "However, it seems that the guidelines may not have been followed in Ms. Suleman's case."

Neither the society or the medical board identified Suleman's physician, Dr. Michael Kamrava.

Kamrava, a specialist who pioneered a method of implantation, was identified Monday as a result of an NBC interview with Suleman, who said she went to the West Coast IVF Clinic in Beverly Hills and that all 14 of her children were conceived with help from the same doctor. In 2006, Los Angeles TV station KTLA ran a story on infertility that showed Kamrava, the center's director, treating Suleman and discussing embryo implantation.

Kamrava, 57, did not return calls seeking comment Monday or Tuesday.

When confronted by reporters outside his clinic Monday, he said he had granted a television interview but would not give details.

In an NBC "Dateline" interview that aired Tuesday night, Suleman said the octuplets were a sign from God that she should stop having children. She also said she still intends to go back to school and finish her master's degree.

Suleman also told NBC she's "not living off taxpayer money," but that she has been receiving about $490 worth of food stamps.

She say her family receives no cash from the government and that the food stamps she's been receiving for 18 months are "not affiliated with welfare."

Suleman has been criticized for trying to have more children when she has no job and seemingly little money.

Responding to her mother's claim that she is incapable of caring for her new family, Suleman said: "What human on this planet is capable to take care of 14 independently without support from family, from friends, from church? No human is."