A 65-year-old German woman who is due to give birth to quadruplets in the summer has defended her decision and says she is looking forward to the challenges ahead.

Annegret Raunigk, who is in her fifth month of pregnancy, said she had decided to get pregnant after her nine-year-old daughter, Lelia, told her she would like a baby sister or brother. "She’s a great kid and I wanted to fulfil her wish,” Raunigk told the German television channel RTL.

She said she found it "quite a strain battling against the cliches” as to what she should and should not be capable of at her age, and if science had enabled her to get pregnant "it should be up to everyone to decide for themselves”.

Raunigk, who has 13 children and seven grandchildren, was open about the fact that her pregnancy was the result of artificial insemination carried out in a clinic in Ukraine using sperm and eggs from anonymous donors, a practice forbidden in Germany.

All four of the fertilised eggs placed in Raunigk’s womb developed into embryos, contrary to her doctors’ expectations. The chance of quadruplets being conceived naturally is otherwise one in 13 million.

Raunigk, a Russian and English primary school teacher who is due to retire shortly before giving birth, did not reveal how many times she had gone through the IVF process or how much it had cost.

She made headlines nine years ago when she became Germany’s oldest mother at the age of 55 after giving birth to Lelia, who she said was conceived naturally. She then appeared on German television with her 13 children, the oldest of whom is now 43.

Apart from Lelia, none of her children have this time wished to share the limelight with their mother, who has again become a household name in Germany since news of her pregnancy came to light last week.

Raunigk, who lives in Berlin but plans to move to a town in North Rhine-Westphalia to be closer to some of her other children before the birth, will hope to finance her children’s upbringing through media coverage and sponsorship deals. She told the RTL show Extra: "I don’t interfere in anyone else’s life and I don’t expect them to interfere in mine.”

Lelia told the show’s host she had wanted her mother to have only one child. "So what shall we do with the others?” her mother joked during the interview.

Her daughter’s expression turned to one of alarm when she heard a doctor tell Raunigk that she was likely to be admitted to hospital soon to prevent premature labour. The quadruplets are due in August but are likely to be born sooner.