The admission, he suggested, means that she cannot invoke the syndrome in her defence.
But Cottrez's lawyer, Frank Berton, countered Friday that the state had been "too hasty" in reaching that conclusion.
"Many psychiatrists will disagree. Just because one is conscious of a pregnancy does not mean that one isn't in denial," he told journalists.
The syndrome has already been used as a defence in other infanticide cases here -- legitimately so, said Sophie Marinopoulos, a psychiatrist at Nantes maternity hospital in western France.
"To my knowledge women do not organise their pregnancies in order to kill their children. It is a case of psychological suffering," she told AFP.
For Israel Nisand, an obstetrician at the Univeristy Hospital in Strasbourg who has testified in court, the problem is all too real.
"When you don't know what it is, of course these women will look like monsters," he said.
Experts distinguish between three types of pregnancy denial.
With so-called pervasive denial, "not only the emotional significance but the very existence of the pregnancy is kept from awareness," notes Laura Miller of Brigham and Women’s Hospital in Boston.
In the case of psychotic denial, unacknowledged pregnancy occurs in women with severe mental illness, sometimes compounded by abuse.
Women with "affective denial," however, are intellectually aware of their condition "but continue to think, feel, and behave as though they were not pregnant," according to Miller.
A woman addicted to drugs potentially harmful to a foetus, for example, may enter this state of mind to assuage guilt feelings.
In all three types, weight gain, changes in the breasts, and even labour pains can all be misconstrued or explained away in the mind of the woman.
Partners and family may also fail to notice changes, especially when the expectant mother is -- as was the case with Cottrez -- severely overweight.
In a study published in Psychosomatic Medicine, Susan Hatters Friedman of Case Western Reserve University in Ohio and colleagues examined records for 31,475 deliveries at the university hospital from 1998 through 2003.
The key tipoff to potential cases of pregnancy denial was women who had not sought any form of prenatal care before delivery.
When combined with other criteria, they found a total 61 cases of denial, a rate of about one in 500.
Instances of complete denial -- including some in which women did not realise they were pregnant until delivery -- were far rarer, about one in 2,500. None involved infanticide.
There were an additional 20 cases of a distinct syndrome called pregnancy concealment in which women consciously hide their condition from family and friends.
Research in Germany and France has yielded similar statistics.
Contrary to expectations, the profile to emerge from the US study was not one of first-time pregnancies among economically deprived teenagers living with parents.
Women were more likely to be well into their twenties, to work and to have no record of family or spousal abuse.
"It can affect women of different ages, education levels and social standings," said Felix Navarro, a physician and president of the French association for the recognition of pregnancy denial.
Pregnancy denial came to public attention in France last year after another dramatic case of infanticide.
Veronique Coujault killed three of her newborns, keeping two of the bodies in her freezer and burning the third. As with Cottrez, the husband said he was unaware of what was happening.
But Roland Coutanceau, a forensic psychiatrist and expert witness in France, is sceptical that the syndrome was a factor for either woman.
"I don't believe in pregnancy denial. We don't need it to explain what happened," he told AFP.
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