The thieves were discovered when a witness in a nearby residence saw them prowling around the apartment in Örby Slott, south of Stockholm.
She called police when she saw two of them climb through a window, while another kept watch below, according to the local Mitt I Söderort newspaper.
When the police arrived on the scene, two men, aged 25 and 27, jumped from the balcony and fled the scene, but were soon caught by police.
When police asked the thieves to empty their pockets, they were surprised to find an umbilical cord among the loot – of which 2,700 kronor ($401) in cash, jewellery and digital music players were included.
“We had saved our newborn baby’s umbilical cord as a memory, kind of like how some people keep a lock of their children’s hair. It’s a tradition in some countries,” said the child’s father to the paper.
Luckily, the family got the precious appendage back as well as everything else that was taken.
The two thieves were charged with aggravated robbery, while another man, 22, was charged for being an accomplice to the theft.
The robbery occurred in January this year, and the 25-year-old admitted in court that he couldn’t remember the event due to being under the influence of pills.
The 25 and 27-year-old were nevertheless each sentenced to nine months prison, while the 22-year-old was given a suspended sentence for aiding and abetting.