Herpes simplex virus (HSV), which commonly causes cold sores, usually causes mild symptoms in adults but can be life-threatening in newborns, whose immune systems are still developing. Meg Edmonds, from Staffordshire, UK, lost her 10-day-old daughter, Magnolia, to HSV in February. “We didn't know a cold sore could kill a baby,” Meg told the BBC. She is now urging parents to learn about the risks cold sores pose to newborns. The virus is suspected to have been passed on to Magnolia by her mother. “The guilt is obviously unbearable; it's horrific, but I just try and remind myself that I didn't know and I did what I could have done with the knowledge that I did have,” Meg said. Mother Did Not Know Cold Sores Could Endanger Newborns Also read: Rare Pregnancy Infections Linked To 3-Fold Higher Autism Risk: What Is TORCH?The 22-year-old said Magnolia was born “perfectly healthy” after what she described as a straightforward “water birth”. Only later did Meg realise she had a sore on her lip around the time of the birth. “Looking back at photos now, I can see that I had a lesion or sore on my lip whilst I was giving birth which I thought nothing of at the time,” she said. Meg, who had never experienced a cold sore before, sought advice from health professionals but was reassured that the sore was nothing to worry about. “They just thought that I might need to drink more or that it might just have been hormonal from giving birth only the day prior, so I thought nothing of it,” she said. Magnolia's condition later deteriorated, and she died from HSV, according to the report. Cold Sore Outbreak Brings Back Painful Memories Meg said she had avoided visitors who were unwell, never kissed Magnolia and washed her hands frequently to protect her newborn from infections. “I washed my hands constantly because I was worried in general about infections. But I never knew that if that passed to her it could kill her,” she said. A subsequent cold sore outbreak brought back painful memories. “I'm constantly reminded anyway that my daughter isn't here any more and why that is, but to actually have a physical reminder on my face is horrible,” she said. How To Protect Newborns From HSV Read More: Baby Not Sitting by 9 Months? Warning Signs Parents Should KnowAccording to the UK's National Health Service (NHS), newborns are particularly vulnerable to HSV, especially during the first six weeks of life. The infection can affect the eyes, mouth and skin or spread to other organs, potentially becoming life-threatening. HSV can spread after birth through contact with a cold sore, including when someone with an active cold sore kisses a baby. It can also spread through herpes blisters on the breast during breastfeeding. The NHS recommends these precautions to reduce the risk of infection: Wash hands: Wash hands thoroughly before handling a newborn. Avoid kissing: People with an active cold sore should not kiss a baby. Prevent direct contact: Keep cold sores and other herpes lesions away from the baby. Take care during breastfeeding: Do not breastfeed from a breast with herpes blisters until they have healed. Seek medical advice about feeding and expressed milk from the affected breast. Inform healthcare professionals: Pregnant women with a history of genital herpes or symptoms of a possible infection should inform their doctor or midwife. Warning Signs Of Neonatal Herpes Babies may not develop visible blisters, and neonatal herpes can progress rapidly. Seek urgent medical attention if a newborn has: Unusual irritability or difficulty settling.Poor feeding or feeds less than usual. A fever of 38°C or higher. A rash or sores on the skin, eyes or inside the mouth. Unusual lethargy, floppiness or difficulty waking. Breathing difficulties or seizures. Prompt medical assessment and treatment are essential because neonatal herpes can become life-threatening.