BELOW THE faded, purplish track marks on Melissa's pale inner arms are Latin words etched in black that mean "To Know Yourself Without Regret."

Not that the 41-year-old Rhawnhurst mom of three, who expects to lose her nursing license for the second time, is without remorse.

She has plenty.

Melissa long ago lost custody of one daughter, who is now 20. Daughter Mady, 8, was born irritable and jittery, with tremors and diarrhea, all symptoms of methadone withdrawal. During pregnancy, Melissa had taken doses of the synthetic opiate at a clinic instead of chasing a heroin high on the street.

Her son, Ian, now 4, was born without evident problems. Melissa said she had tried to stay drug-free and injected heroin about five times during that pregnancy.

With America in the throes of a heroin and opiate epidemic, and with people in Philadelphia dying from overdoses in record numbers, an increasing number of babies are born battling drug withdrawal.

This condition, called neonatal abstinence syndrome, has led to increasing numbers of critically ill infants being treated in neonatal intensive-care units (NICUs) around the country, including Philadelphia.

In fact, the rate of cases almost quadrupled in the decade ending in 2013, skyrocketing from seven to 27 cases for every 1,000 NICU admissions, according to a study published May 28 in the New England Journal of Medicine.

And the median length of stay jumped from 13 days to 19.

Medical costs to treat these babies is soaring.

Care for a healthy newborn averages $3,500. The price tag for an infant treated and medicated for withdrawal averages $65,000 to $70,000, according to Endla K. Anday, clinical director for neonatal services at St. Christopher's Hospital for Children.

"Some of these babies stay for weeks," Anday said. "Many weeks."

Anday and other specialists say that in addition to heroin, a growing number of pregnant moms are using opiates in pill form like OxyContin, Percocet and Vicodin - some prescribed, some bought on the street.

"Many babies are exposed to multiple drugs," said Heidi Taylor, medical director of the intensive-care nursery at Temple University Hospital.

At delivery when the umbilical cord is severed, the baby is cut off from the drug supply. Some symptoms can be seen as early as 12 to 24 hours after birth. Most kick in within two to five days.

Withdrawal in babies is similar to withdrawal in adults. The infants are irritable and restless, and breathe fast with high heart rates. They sweat, have fevers and diarrhea, tremors, even seizures. They can vomit, cry excessively, stay constantly awake, unable to sleep.

"Some of them can't settle enough to take milk from the bottle," Taylor said.

Doctors use a scoring system to evaluate the severity of the withdrawal. Babies are then often given oral morphine and slowly, carefully weaned off.

"That's why it takes so long," Anday said. "It's a long and arduous process, and they are monitored very closely."

"Certainly these infants suffer," Taylor said. "It's a difficult thing to watch what babies go through."

Hospital workers encourage the moms to spend time with their babies in the hospital to try to soothe and comfort them.

"It's very important to support them with swaddling, gentle cradling, noise control," Taylor said.

The Department of Human Services investigates the cases. Social workers try to determine if the moms should keep custody of the infants.

Because relapse is part of addiction, Melissa has been on and off heroin for years. She was arrested in April for drug possession and went into a treatment program. This time she decided to go drug-free without methadone.

Melissa now lives with Mady and Ian at Gaudenzia Kindred House, a residential treatment center in West Chester. Supervisors there said her last name could not published for confidentiality reasons.

"Knowing myself is not a regret," said Melissa, smoothing back her brown hair pulled tight into a ponytail.

"I have to address my addiction first before I can be anything else. If I don't look at that, I can't be a mother or a nurse," she said.

"That's got to be the primary focus of who I am. If I don't address that, everything falls apart."

She acknowledged that people may hate her for using drugs while pregnant.

"No pregnant woman wants to use drugs," she said. "I didn't want to. I regret exposing them to drugs because, no matter what, it negatively affects them. There's no getting around it."

'My mom was fed up'

On the night of Sept. 28, 2014, on a porch in Darby Township, Taneya Nickerson went into labor with her fourth child.

She was high, as she had been the entire pregnancy.

She had smoked crack, pipe after pipe, drank beer and downed five or six Percocets over about 12 hours. The crack thrust her into a heart-racing frenzy; the opiates calmed her down.

"I felt a contraction but I was not leaving till all the crack was gone," she said recently.

Nickerson finally called a friend, who took her to the hospital.

"I still had the glass pipe and crack in my pocket," she said.

Her daughter, Kya, was born at 32 weeks' gestation and weighed only 3 pounds 10 ounces. Doctors rushed the tiny infant to the NICU. Nickerson was transferred to a room where she went to the bathroom to smoke what crack she had left.

Meanwhile, Kya struggled. Her lungs were not fully developed. She needed oxygen and a feeding tube. She was jaundiced and had the shakes.

Nurses put a mask over her eyes to calm her and shield her from bright lights.

Nickerson, 37, had used drugs while pregnant with her older three daughters, now ages 21, 14 and 12, she said. But Kya was the sickest.

Her mom had always stepped in and taken care of her older children.

But things changed after Kya was born. "My mom was fed up," she said.

" 'You can't bring that baby home,' " her mom told her.

"I love her for that," Nickerson said after a brief pause.

At the same time, a social worker knew she was getting high and told her he wouldn't let Kya go home with her.

Nickerson was at a crossroads. "I didn't want my kids to see me give their baby sister away because I still wanted to run around and get high," she said.

On Oct. 18, 2014, she went into inpatient drug treatment at Gaudenzia.

She's been sober ever since.

At first, however, she had no interest in seeing Kya.

Karen Thomas, program director at Gaudenzia Kindred House, said she told Nickerson, " 'No. You're going to visit your baby.' We made up a schedule and worked with her on parenting and bonding."

After more than a two-month hospital stay, Kya was released last December and came to live with Nickerson at Kindred House. In April, Nickerson moved with Kya to a Children and Youth Services shelter in Chester. Her other two children joined her.

"I'm a different person now," she said. "I learned so much about myself."

"My daughter has the best of me. And I'm glad my mom can be at peace, knowing I'm OK and taking care of my kids."

'Created on opiates'

Further research is needed to know more about the long-term effects of having to withdraw from heroin and opiates after birth, experts say. But growing up in a healthy, nurturing environment can make a huge difference, they say.

For years, studies have focused more on cocaine exposure. But children exposed to opiates may be more likely to have short attention spans and behavioral issues, Anday said.

And they are at higher risk for abusing alcohol and drugs, she said.

"It affects the way the brain cells talk to each other in the reward-seeking area of the brain," she said.

Melissa often wonders whether she set up her daughter to become addicted.

"To this day, I always think to myself, '[Are] there going to be any lasting effects from me being on methadone while I was pregnant?' " Melissa asked.

"For Mady, I worry that biologically she was created on opiates and if you ever put opiates in your body, what's going to happen to you?" she asked.

"As an addict and a parent, I worry if you ever experimented.

"That's my fear for her. I wouldn't want it for her."

On Twitter: @barbaralaker