Bruising in a baby who is not yet mobile
A bruise on a baby who cannot yet crawl, pull to stand or toddle is a red flag for physical abuse.
Remember
Ask whether the child could have caused the injury in the way described, given what they can do: a baby who cannot yet crawl, pull to stand or toddle is rarely injured by accident, so any bruise needs careful assessment.
Memory aid
those who don't cruise rarely bruise
To cruise is to move around furniture, and this rhyme helps you remember the youngest, most important group: babies who are not yet mobile.
Bruising needs force. A baby who cannot yet crawl, pull to stand or toddle is not yet mobile (cannot move around independently), so cannot injure themselves through normal activity. Babies like this are rarely injured by accident, which makes any bruise or mark on one a red flag for physical abuse.
The general principle is to ask whether the child could have caused the injury in the way described, given their developmental ability (what the child can actually do). Mobile children get bruises, grazes and scratches constantly, mainly over bony prominences (the parts that hit the ground or furniture first), such as the knees, shins and forehead, and these are usually unremarkable. More worrying are bruises on non-bony parts of the body or face (including the eyes, ears and buttocks), bruises in clusters, and bruises in the shape of a hand or implement.
Mobility is judged from what the child can actually do, and age alone should not decide it.
A bruise in a baby who is not yet mobile is a reason to assess carefully, not a diagnosis by itself. A bleeding or clotting disorder (a coagulation disorder) can also cause bruising. So record the bruise, consider a medical cause, and discuss the baby with a senior colleague or the safeguarding lead rather than offering reassurance.
Physical abuse does not always leave marks on the skin. Unexplained drowsiness, vomiting or breathing difficulty can reflect an occult injury (an injury that is hidden from view), such as a head injury or poisoning.
Key facts
- Red flag
- A bruise or mark on a baby who cannot yet crawl, pull to stand or toddle should be investigated and carefully recorded.
- How rare
- In one study of children younger than 6 months, only 0.6% had any bruise at all.
- Medical cause
- A coagulation disorder (a problem with blood clotting) can also cause bruising, so a bruise in a baby who is not mobile is not proof of abuse.
- Judging mobility
- Whether a child is independently mobile depends on what they can actually do, and age alone should not decide it.
- Hidden injury
- Physical abuse does not always leave marks on the skin, so unexplained drowsiness, vomiting or breathing difficulty can reflect an injury that is hidden from view.
- Next steps
- Document the bruise carefully, think about a medical cause, for example a coagulation disorder, and talk to a senior colleague or the safeguarding lead.
Exam traps
- A bruise on a limb rather than the trunk is no less worrying in a baby who cannot move around, because the concern comes from the bruise itself and its position is one more detail to note.
- A carer who looks calm and cooperative does not show whether a child has been harmed, because how a caregiver looks in the room tells you nothing about how an injury happened, so the findings and whether the explanation fits are what assessment rests on.
- A uniform blue-purple colour cannot reliably show how old a bruise is or whether it was accidental or inflicted, so in a baby who cannot move around, the lack of mobility is the stronger warning sign.
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