Douai, France (CNN) -- French prosecutors said Thursday they charged a woman with murder after she admitted giving birth to and smothering eight babies over a 17-year period in northern France.
The woman, Dominique Cottrez, said she hid the pregnancies and deaths from her husband, who said he had no idea what she had done, prosecutor Eric Vaillant told reporters. Cottrez is overweight and was able to conceal the pregnancies, he said.
Cottrez told investigators the reason she killed the babies was that she did not want to have any more children and did not want to see doctors for contraceptives, Vaillant said.
Despite earlier reports that the husband had been charged, Vaillant said he was free to go but may still be investigated. Vaillant said he personally still had "doubts" about the father's story.
"The sky has fallen in on his head," Vaillant said of the father, Pierre-Marie Cottrez. "He indicated he had no idea she was pregnant."
Vaillant said there are no other babies' bodies left to be found.
The case came to light when a couple gardening in their backyard in the northern town of Villers-au-Tertre found two babies' bodies in sealed plastic bags and called police.
Police spoke to Cottrez and her husband, who had previously lived in the home, and Cottrez admitted immediately that she was the mother of the two babies, Vaillant said. She then told police about six others concealed in their garage, Vaillant said.
Those six bodies were also in sealed plastic bags but were covered by various objects, he said.
Cottrez, a nurse, had psychological problems from her first pregnancy, said Pierre-Jean Gribouva, the lawyer for her husband.
"My client is in a deep state of shock," Gribouva told CNN affiliate BFM. "He had no idea about this. He has totally fallen apart."
The babies were born between 1989 and 2006, but their exact birthdates aren't known, Vaillant said.
"She knew that she was pregnant every time, and she has admitted this," Vaillant said. Cottrez "answered in a very straightforward way."
Cottrez and her husband have two adult daughters, but it was a difficult first pregnancy that sparked her actions, Vaillant said. Because of her weight, the first pregnancy was "traumatic," and she didn't want to go through it again, he said.
Vaillaint did not explain why Cottrez went through a second pregnancy with her other daughter before apparently committing the crimes.
Pierre-Marie Cottrez hopes the public does not make "simplistic conclusions" about his wife, Gribouva told BFM.
The family members "are supporting the wife and the mother because they realize she has serious problems," he said. "There is no rejection of her as a wife and mother."
Psychotherapist Lucy Beresford told CNN that very little was known about incidences of infanticide because it was a taboo subject. A paper published in the Journal of the American Medical Association by researchers in North Carolina estimated that 2.1 cases of infanticide occurred for every 100,000 births, but Beresford said the body of psychological research was "slim."
Research suggested that women who denied or concealed their pregnancies, for whatever reason, were a "high-risk" group, she said. But other factors could trigger infanticide as well.
"It could actually be to do with the social isolation of the mother, or it could be their psychopathology prior to pregnancy," Beresford told CNN.
"For example, do they have a history of substance abuse or other mental health concerns that have contributed to them being in this situation which they cannot accept as a reality?"
Postnatal depression could also be a possible contributory factor, she said.
"That could be because when they're depressed they're not really of sound mind. It could be that they genuinely believe they are unworthy to be a parent. Or it could just be the level of disordered thinking that comes with being depressed."
CNN's Phil Black contributed to this report.