The RCS is behind the publication, which warns that early diagnosis is imperative to avoid leaving babies unable to feed and gain weight.
National standards state that clefts should be diagnosed within 24 hours of birth to enable immediate referral to a specialist hospital.
This ensures the baby, and family, receive appropriate care, help and support as soon as possible.
But the report highlights that 28% of babies with a cleft that affects the roof of the mouth alone are diagnosed outside of this target, with 5% remaining undiagnosed until after one month of age.
Mervi Jokinen, RCM practice and standards development advisor, said: ‘This is an important clinical issue that health professionals caring for newborn babies should be aware of.
‘Though cleft lip and palate are often picked up via antenatal screening programmes and cleft lip can easily be recognised at birth, the other externally less visible forms of cleft palate can be missed without a thorough examination and the correct technique when undertaking a physical examination of a newborn baby.
‘The RCS report reflects the advice given in our own learning resource on the examination of the newborn. We advise that a full examination – including an examination for cleft lip or palate – is undertaken within 72 hours of the birth, as the current national Screening Standard states.'
The CRANE database at the RCS collects information on all children born with a cleft lip and/or palate in England, Wales and Northern Ireland.
The report calls for national and local guidelines for examining newborns to be reviewed to reduce the risk of a missed diagnosis.
The report reveals that late diagnosis of cleft palates varies substantially across the country, indicating that some maternity units are better than others at identifying clefts during the newborn examination.
For example, only 42% of cleft palates were identified within 24 hours of birth in the North Thames area, whereas 94% were identified at birth in the Oxford area.
Scott Deacon, lead consultant orthodontist and clinical lead of the CRANE database, said: ‘A cleft palate is a serious condition as it can leave babies unable to feed and gain weight; it can also be indicative of other health problems.
'It is crucial that a thorough visual examination of the mouth and palate is carried out within 24 hours of birth to ensure the baby, and their family, receives the care and support they need from the outset.’
To read the report in full, please click here