The causes of cleft lip and cleft palate (or both) are unknown, although hereditary (genetic) factors sometimes play a small role. A cleft lip or cleft palate (or both) is not caused by anything the parents did or did not do during the pregnancy.

What causes a hair lip?

Cleft lip and cleft palate are thought to be caused by a combination of genes and other factors, such as things the mother comes in contact with in her environment, or what the mother eats or drinks, or certain medications she uses during pregnancy.

Can cleft lip be passed down?

Most cases of cleft lip or palate are a one-off and it's unlikely you'll have another child with the condition. The risk of having a child with a cleft lip or palate is slightly increased if you've had a child with the condition before, but the chances of this happening are thought to be around 2 to 8%.