Andrea Goeppner, 45, was charged with four of the murders after the babies' remains were found wrapped in towels and plastic bags last year in a case that revulsed the country.
Asked how many of the eight she confessed to killing, her defence lawyer Till Wagler said, "it could have been two, three or four".
Prosecutors were unable to pursue murder charges for the other four infants, as one was found to have been stillborn and three were so badly decomposed that it was unclear whether they were viable at birth.
The woman's estranged husband, Johann Goeppner, 55, is charged with complicity for failing to stop the killings, which took place between 2003 and 2013.
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In her confession, read out by her lawyer, the mother said she had given birth to each of the eight babies at home alone and had wrapped every infant in a hand towel.
She would promptly suffocate any baby that moved or cried, then place the body in a plastic bag or containers and hide it in the apartment, said Wagler.
Even though they did not want any more children, they used no contraceptives, and Andrea Goeppner was almost constantly pregnant over a decade.
State prosecutors in their charge sheet said her actions showed "sexual egoism, indifference and callousness".
"She sought simply to remain sexually active without any thought about the consequences or the value of a newborn child."
Taking the stand today, her now estranged husband described the mother as a chronic liar and compulsive shopper who stole from her mother and her children.
Prosecutors say the man was aware of his wife's frequent pregnancies and could have taken action to stop them.
"Through his inaction, he encouraged the accused, Andrea Goeppner, in all the cases," they said.
In Germany, murder carries a sentence of 15 years' prison, while complicity carries a minimum of three years.
A verdict is expected next Wednesday.