A new study from the Archives of Pediatrics & Adolescent Medicine has reportedly identified that some antibiotics used to treat urinary tract infections may increase the risk of birth defects in a child if used during the early period of pregnancy.

In particular the research found there was an increased risk from using sulfonamide and nitrofurantoins. More common prescriptions for pregnant woman such as penicillins and erythromycins are, however, thought to be safe.

During the investigation, researchers looked at the use of six different classes of antibiotics in over 13,000 women whose babies had been affected by at least one of 30 major birth detects and 5,000 women gave birth to defect-free babies.