LOS ANGELES — The fertility doctor who helped a California woman have 14 children, including octuplets born last month, is now facing a state investigation on top of harsh criticism from medical ethicists.

The Medical Board of California did not identify the doctor who helped Nadya Suleman, 33, of Whittier, become pregnant with the six boys and two girls born on Jan. 26. Suleman has six other children.

“We’re looking into the matter to see if we can substantiate if there was a violation of the standard of care,” board spokeswoman Candis Cohen said Friday.

Suleman, a divorced single mother, told NBC’s “Today” show that the same fertility specialist provided in vitro fertilization for all 14 children using sperm donated by a friend.

In the interview broadcast Friday, Suleman also said six embryos were implanted for each of her pregnancies. In her latest, two of Suleman’s embryos split, resulting in two sets of twins among the octuplets.

When asked why so many embryos were implanted, Suleman said: “Those are my children, and that’s what was available and I used them. So, I took a risk. It’s a gamble. It always is.”

In the United States, there is no law dictating the number of embryos that can be placed in a mother’s womb. Doctors say the norm is to implant two or three embryos, at most, in women Suleman’s age.

“The revelation about one center treating her makes the treatment even harder to understand,” said Arthur Caplan, bioethics chairman at the University of Pennsylvania. “They went ahead when she had six kids, knowing that she was a single mom … and put embryos into her anyway.”

Suleman’s infants were born prematurely and are expected to remain in the hospital for several more weeks. Her six other children are between ages 2 and 7.

Suleman said she had never been on welfare and would find a way to get by with the help of family, friends and her church. She said she planned to return to school in the fall.

The births have raised questions about how the woman will be able to care for all of her children. Los Angeles County child welfare spokesman Stu Riskin said the agency doesn’t respond unless there has been a complaint, and such complaints are confidential.

“All I wanted was children. I wanted to be a mom. That’s all I ever wanted in my life,” Suleman said in the portion of the interview that aired Friday. “I love my children.”

She said she struggled for seven years before finally giving birth to her first child.