Health officials have identified three further cases of blood poisoning that have been linked to the suspect batch - bringing the total number of cases to 21.
Public Health said that the babies, who became unwell last week or over the weekend, are responding to antibiotic treatment.
The cases were identified after analysis of clinical records of the babies, a spokeswoman said.
The father of baby Yousef Al-Kharboush, who is believed to have died from blood poisoning because of a contaminated feed at London's St Thomas' Hospital, has told a coroner's review he doesn't want any other babies to suffer and die as his son did.
Raaid Hassan Sakkijha told the review: "My son died, I hope he can save other children given what's happened."
After the meeting he praised the hospital for excellent care, saying: "This is life. These things happen."
The review heard that three investigations are now underway to establish what happened.
The pharmaceutical manufacturer behind a batch of intravenous liquids linked to 18 cases of blood poisoning in babies, has said it is still using the same ingredient in new batches, from the same supplier.
An ITH Pharma spokesman added they are not still using the same batch of products that is believed to be affected while the batches are created to order, for a single day's use and have a seven-day shelf life.
ITH Pharma is inspected every three to five years. It passed its last inspection which took place in April 2012, the spokesman said. They also claimed that its workers undergo a "rigorous and continuous" training programme, recognised by the MHRA, which is led by an in-house team.
A leading expert on premature babies has described the fatal outbreak of blood poisoning in London hospitals as "very worrying".
Dr Colin Michie, a consultant paediatrician, said the fluid, called Total Parenteral Nutrition, was vital in the treatment of premature babies.
As 18 babies have been struck down with blood poisoning after contracting an infection from a suspected contaminated drip, here is what the intravenous fluid is thought to have been contaminated with:
- Bacillus cereus is a bacterium found in dust, soil and vegetation.
- It produces very hardy spores which in the right conditions can grow and create a toxin which causes illness.
- It is likely to be on most surfaces.
- These toxins can cause two types of illness: one type characterised by diarrhoea, and the other, by nausea and vomiting.
- The duration of the illness can last about a day.
- The symptoms can begin to show after six hours.
There is more to be done over patient safety, the Health Secretary has said, after a batch of a food supplement was "strongly linked" to the death of one baby and the illness of 17 others.
Speaking at the NHS Confederation's annual conference in Liverpool, Jeremy Hunt said: "The truth is that we have come a long way (in patient safety) but we have a lot further to go.
"Today's story about the tragic blood poisoning of 18 children shows we can never take safety for granted. It also shows the importance of prompt and early identification of problems".
Three more cases of blood poisoning linked to a batch of intravenous liquid given to babies have been identified by health officials.
Public Health England (PHE) said yesterday that a batch of a food supplement was "strongly linked" to the death of one baby and the illness of 14 others.
PHE officials have now identified three further cases of septicaemia in babies being treated in neonatal units in hospitals in England - bringing the total number of cases to 18.
One case was confirmed at Peterborough City Hospital in Cambridgeshire and two probable cases have been identified at Southend University Hospital and Basildon University Hospital, both in Essex, she said.
The suspected contaminated batch of a food supplement linked to the death of one baby and the illness of 14 others was sent to 22 different hospitals, including three in the South East, the medicines regulator has said.
Medicines and Healthcare products Regulatory Agency (MHRA) said the batch was sent to both private and NHS hospitals across England.