A Dutch woman received a maximum 12-year prison sentence Tuesday for smothering her four newborns in an effort to conceal her pregnancies and keep up the appearance of being a perfect daughter.

The woman, identified only as Sietske H. in line with Dutch privacy laws, was arrested last year after the babies' decomposed bodies were discovered in four suitcases in the attic of her house. They were born between 2003 and 2009.

The District Court in the northern city of Leeuwarden convicted her of one count of manslaughter and three counts of murder.

She claimed she did not want anyone to know she was pregnant and managed to conceal all four pregnancies, even from the father, before killing the newborns.

The court heard that the woman killed her first by smothering her with a cushion to stop her crying. She suffocated the next three because she did not want to go to an abortion clinic, fearing questions about her earlier pregnancy, judges said.

"The suspect's argument that she wanted to be the perfect daughter for her parents is understandable to a certain extent," the judges said in their written judgment. "It is incomprehensible that she let this wish override the lives of four newborn babies."

Explaining their decision to impose the maximum sentence, judges said the case was about "terrible facts where a mother killed her totally defenseless babies with a pillow or her bare hands."

The court said it was a mystery why the woman, who refused to undergo a court-ordered psychological evaluation, became pregnant three times after killing her first child.