The bodies of five boys were found in a house in the village of Darry, on Germany's northern Baltic coast, after their mother confessed to police.
Their 31-year-old mother, who has not been named, has been placed in psychiatric care.
Autopsies will take place on Thursday, but the woman said she had given the children sleeping pills, subsequently suffocating them with plastic bags.
In the second case, police took into custody a 28 year-old woman from Plauen after the discovery of three dead babies.
Police began investigating the woman after a check was carried out as to why her child had not undergone an obligatory medical examination before starting school.
The woman told social services that the girl's father was a foreigner, who had taken her abroad shortly after she was born. However, after questioning, the woman showed them a suitcase containing a body wrapped in plastic, saying that the baby had 'unexpectedly' died several days after birth.
A forensic expert said that the baby's body was almost completely mummified and the cause of death could not be established. The woman was initially released as there was not enough evidence to charge her.
A week later, police discovered two more corpses, also wrapped in plastic, and the woman was arrested. The bodies had been stored in the woman's freezer and on her balcony. The woman, who has also not been named, denies murdering the babies.
The discovery of the bodies recall a similar case that shocked Germany last year when a woman was jailed for 15 years for killing eight of her own children in a small town on the country's eastern border.
The woman, 40 year-old alcoholic, Sabine Hilschenz, admitted to having killed some of her babies shortly after giving birth to them, saying that her husband did not want a child. She said she did not remember how she had killed the other babies, as she was often drunk.
The remains of the infants were found hidden in flower pots and a fish tank in her parents' garden.
