In episodes which aired on New Year's Eve and New Year's Day, viewers saw new mum Ronnie Branning (Samantha Womack) discover that her newborn son had fallen victim to cot death, before desperately swapping the child with Kat Moon's (Jessie Wallace) baby in her grief-stricken state.
This afternoon, the BBC confirmed that complaints over the plotline have now topped 3,400. The total includes all of the complaints which have been received since the tragic story was first announced in November.
In a statement released today, EastEnders' executive producer Bryan Kirkwood commented: "We appreciate this is a challenging storyline and have taken care to ensure viewers were aware of the content in advance of transmission.
"We also provided actionline numbers at the end of each show, offering advice and support to those affected by the issues."
While devising the storyline, the EastEnders team worked closely with the Foundation for the Study of Infant Deaths (FSID) with the aim of providing a sensitive portrayal of the issue of cot death.
Show bosses also took the decision to make a number of small last-minute changes to the episodes in question to avoid upsetting viewers.