An epidemic of opioid and heroin addiction is sweeping across the US and children are its most vulnerable victims. Many newborns diagnosed with a drug dependency called Neonatal Abstinence Syndrome go unreported.

Those babies are sometimes born into misery. Some shake, struggle to eat and often sputter and choke during feedings. They can suffer fits of sneezing and severe diarrhea. Many begin crying at the smallest stimulus, including a mother's smile. They can cry with such force that their bodies shudder.

Federal law calls on states to require that hospitals notify child protection services when babies are born dependent on drugs. But a Reuters investigation found 110 examples since 2010 of babies dying preventable deaths after the infants and their mothers were discharged from hospitals - even as the mothers struggled with addiction and were ill-equipped to care for themselves or their infants. In 2013, 27,000 babies were born dependent on drugs, more than five times the number in 2003.

Braxton was born dependent on methadone, the drug his mom was taking in an effort to get off heroin. He's had to overcome withdrawal symptoms such as tremors and oversensitivity. And he still has difficulty feeding. His mother, Clorissa Jones, enrolled in a special program for moms battling drug addiction. The program may have saved his life and hers, she said.

"I know Braxton saved my life in the fact that I was able to stay clean through my whole pregnancy and I'm still clean right now. It's him I look forward to every day, you know?"

Jones says her first son, Jacoby, was born dependent on heroin and even after she took him home, she continued to use, bringing Jacoby with her to buy drugs.

"I was in labour, in the bathroom shooting heroin about to give birth to my child," she said.

"A lot of people are like, 'How could you dare do that? How could you dare do that to your child?' But nothing matters except for getting high. When I'm getting high, nothing matters, I'm very selfish, I'm self-centered."

Jones lost custody of Jacoby and then discovered she was pregnant a second time, with Braxton.

She found her way into the Johns Hopkins University Hospital program for addicted mothers in Baltimore, which gave her shelter and monitored her use of drugs that were prescribed to help her deal with her addiction.

Dr. Lauren Jansson, associate professor of pediatrics at the Johns Hopkins University School of Medicine, treated Braxton.

"It's hard to provide this level of service to these populations because it's expensive, frankly," she said.

"But if you don't provide these services to pregnant women at a time when they need it and not a month later, when they need, when they're ready for treatment, if you don't provide the services then, they won't get access and what will happen is you'll have women that are the unfortunate women that don't ever access substance abuse treatment.

"They deliver infants that are removed from their custody, they wind up with significant health problems because they're continuing to use, those are the horror stories, that costs much more down the line than providing this care during pregnancy that's comprehensive and addresses all the needs of the mother, her pregnancy and then the infant after birth."

Braxton entered the world like more than 130,000 children born in the US in the past decade - hooked on drugs.

"It is a crisis, it is an epidemic," Jansson said.

"The opioid crisis in this country is continuing to expand exponentially. And we're seeing more and more of these infants."

Programmes such as the one at Johns Hopkins are few and they're scattered across the country, but they can make all the difference for a mother and a child, the likes of which could have helped save the life of Reanne Pederson's baby, Avery.

Avery accidentally died in Pederson's care last year. She was using drugs, including snorting hydrocodone.

Shortly after giving birth, Pederson crushed and snorted a hydrocodone pill. She fell asleep while breastfeeding. Her son Avery suffocated to death. He died five days after he was born.

Pederson pleaded guilty to negligent homicide in the June 2014 death. She admits to snorting hydrocodone late in her pregnancy and smoking methamphetamines shortly before Avery was born.

"I spiraled out of control," she said, on losing Avery.

"I was using more and more and didn't really care about the consequences because I had already lost everything besides just Avery, my kids, my house, my job and my car, everything, so I really had nothing to live for at that point. I just lost it."

Hospital records reviewed by Reuters indicate that the hospital where Avery was born, Essentia Hospital in Fargo, North Dakota, made little effort to scrutinize the drug-addicted mother and her child. A labor and delivery nurse caught Pederson in a lie about having a doctor's approval of one drug. Yet no one at the hospital checked a state prescription database that would have revealed her extensive use of addictive drugs during pregnancy.

Medical records indicate Avery may have been born addicted to drugs. In the records, he is described as "jittery," a possible symptom of Neonatal Abstinence Syndrome. But the hospital never tested the newborn or his mother for drugs, medical records show.

Almost a decade ago, a survey done by the U.S. Department of Health and Human Services highlighted how rarely hospitals test children for drug exposure.

The survey was done in 2005-2006, when the U.S. painkiller epidemic had not reached nearly the proportions it has today.

Pederson said she began using opioids the way many addicts start: with a doctor's prescription for painkillers. The pills were meant to help treat jaw pain, but she said she began to crush and snort them. When Pederson got pregnant, she vowed to stop once she could hear Avery's heartbeat at the doctor's office. But she couldn't stop, she said.

"You're so clouded when you're using and when you're an addict you think everything you're doing is okay, you're not doing anything wrong, there's nothing wrong with what you're doing," she said.

Late in her pregnancy, Pederson visited an emergency room three times in a 17-day period, complaining of pain. Each time, she was given hydrocodone. The day before Avery was born, Pederson said she smoked meth. But despite Avery being "jittery," as noted in his medical records, the hospital dismissed the need for a drug test or an assessment for withdrawal. Days later, Avery was dead.

After spending time in jail and drug rehabilitation, Pederson returned to her hometown of Devils Lake, North Dakota.

"Shouldn't be using drugs, not while you're pregnant, not while you're breastfeeding, not while anything of you is contributing to somebody else," she said.

"I mean I know that now, but when you're using you think it's okay."

In her bedroom, Pederson's bottles of prescription painkillers have been replaced by a picture frame a few inches deep. On the front is a photo of Avery. Behind the picture is an urn that holds the newborn's ashes.

The Keeping Children and Families Safe Act passed in 2003 was intended to protect the growing number of drug dependent newborns, alerting authorities when a baby is born drug dependent.

But the Reuters investigation discovered that social services never hear about thousands of these newborns. Former congressman Jim Greenwood championed the bill.

"The people are not following the law," Greenwood said.

"The states are not abiding by the law, it says that the hospitals are not abiding by the law, the doctors are not abiding by the law and in many instances the social service agencies that are there to protect the children are not doing their job either."

In each of those 27,000 cases of drug dependent babies born in 2013, hospital workers were aware of the baby's drug dependence. They diagnosed and treated the child for Neonatal Abstinence Syndrome.

But data kept by state governments suggest that thousands of these children are never reported to child protection authorities. Reuters made that determination by comparing the number of newborns diagnosed by hospitals as drug-dependent with the number of cases referred to state child protection authorities. Only seven states specifically tracked referrals of newborns in drug withdrawal. In those states, the total number of cases logged by child welfare services was less than half the number of children diagnosed.

In the so-called crack-baby epidemic of the 1980s, public concern focused on the long-term development of children exposed to cocaine in-utero. Less examined was whether babies born with narcotics in their bodies were endangered not just by the drugs but also by being sent home, unsupervised, with a mother struggling with addiction.

The Keeping Children and Families Safe Act orders states to set up systems that ensure newborns with symptoms of drug withdrawal be reported to child protection services. Social workers are then to review the cases immediately and develop a plan of safe care for the child.

The law also makes clear that referrals by the hospital are not to be construed as evidence of abuse or neglect. The amendment passed with almost no opposition, but the law continues to meet resistance.

"The purpose of the act is to protect the baby," Greenwood said.

"The fact that the baby is born addicted to drugs should be a big red flashing light that says, 'Danger, let's all take a look at this child and its mother and its family and its residence and see if it's safe.'"

The act's intention was to ensure protection for drug-dependent newborns, not to punish their mothers.

"Anyone who thinks calling child protective services to protect a very vulnerable baby is punitive needs to take a good close look at themselves," Greenwood said.

"That's not the case, it was never meant to be punitive If I had wanted it to be punitive I would've put criminal sanctions in, I would've had mandatory custody of the child taken from the mother. That's not what we wanted to do, we wanted a humane, a non-punitive approach."

The monitoring of mothers and children varies drastically from state to state, hospital to hospital and doctor to doctor. Even public health officials aren't certain of what's required. In some states, a referral to child protection services can put a mother in legal peril. That dissuades some doctors from reporting the cases no matter what the federal law says.