England and Wales: One in 46 Babies has a Birth Defect

England and Wales also has higher rates of neural tube defects such as spina bifida than many other European countries. The report, from the British Isles Network of Congenital Anomaly Registers (Binocar), is the most comprehensive of its kind, covering six regions of England and Wales.

One in 46 babies has a birth defect - although the figure could be as high as one in 40, according to new research.

The authors of the report estimate there were 15,966 babies suffering defects in 2011, or 2.2% of babies. The most common anomalies are congenital heart defects, which affect at least six in every 1,000 babies. Those suffering heart problems can require major surgery, and around 6% of babies with a heart defect die before their first birthday.

Neural tube defects, such as spina bifida, affect one in 1,000 babies, according to the report.

The authors estimated that overall in 2011 4,461 babies suffered heart defects, 1,739 had defects of the nervous system, 1,223 had problems with the digestive system and there were 1,143 cases of cleft lip or palate, alone or alongside other defects.

Some 1,973 babies had Down's syndrome - a rate of 25.7 per 10,000 births - with older mothers at higher risk of having a baby with the condition. The south east and London had the highest rates of Down's, reflecting the fact more mothers over 35 live in these areas. In London, the rate for Down's syndrome was 31 per 10,000 births.

Joan Morris, professor of medical statistics at Queen Mary, University of London, said the 2011 figures did not suggest an overall increase in the number of babies suffering defects compared to previous years.

"It's stayed pretty much the same," she said. "One in 46 babies were thought to have a defect in 2011, although we know this is an underestimate and it's likely to be closer to one in 40. Overall, our impression is that we're pretty similar to Europe although we have higher rates of abdominal defects, particularly among younger mothers.

"People feel this is lifestyle related. Evidence suggests that risks are increased, particularly in lower body mass index mums - the thinner teenage pregnancies - but we can't say that's definitely the cause. We also have higher rates of neural tube defects than other countries but it's not exactly clear why."