Around 20 babies born to drug-dependent mothers had to be given withdrawal treatment at Milton Keynes Hospital last year

Morphine and methadone were among substances given to the tiny tots to wean them from drugs used in pregnancy by their mothers.

Neonatal Abstinence Syndrome (NAS) results from unborn babies being exposed to addictive, often opiate-based drugs like heroin, codeine or benzodiazepines like diazepam.

Drug-dependent infants can soon develop severe withdrawal symptoms, signs of which include a continuous high-pitched cry, feeding problems, profuse vomiting, tremors, face scratching and convulsions.

Treatment involves weaning the baby from the drug on which it is dependent, with morphine often used when mothers have been taking opioids.

In 2017-18, 20 hospital trusts in England recorded 20 or more medical interventions - in 2019-20, 59 did

The true scale of the issue is likely to be greater than figures suggest, given that many infants born with drug dependency will not require medication.

Experts believe up to 80 per cent of drug-exposed infants develop NAS, with some babies continuing to have symptoms up to six months after discharge from hospital.

Symptoms associated with the syndrome do not only occur with the use of illicit substances but can also be due to the consumption of prescription drugs.

In some cases, babies born with NAS will be taken into care.

Dr Alison Wright, spokesperson for the Royal College of Obstetricians and Gynaecologists, said substance use during pregnancy could have a serious impact on the health and bonding of mother and baby.

She warned that "complex barriers" stood in the way of mothers-to-be disclosing their drug use but urged women to seek help.

Dr Wright said: “We would encourage all pregnant women who use recreational drugs to speak to their GP, obstetrician or midwife, who will be able to offer non-judgemental and appropriate advice, help and support."

Health service guidelines state that pregnant women misusing substances need “supportive and coordinated care” during pregnancy and that healthcare staff should work with social care professionals to overcome barriers to care for them in a coordinated way.

Sharon Mallett, Director of Nursing at drug, alcohol and mental health charity We Are With You, said drug-using mothers often experienced "overwhelming guilt and shame" and called for midwives and other experts to work together to create non-judgemental environments.

She added: "The earlier parents seek support the more positive the results are for both the mother and child. That’s why it’s really important not to judge mothers who do come forward around this issue."