Amid nationwide opioid lawsuits, attorneys for newborns suffering from exposure to opioids in the womb have made a last-ditch plea for special legal treatment for the infants and their guardians.

Lawyers from 20 firms representing a group that may number more than 250,000 children have spent much of the past two years seeking a separate trial against drug companies but have been rebuffed twice by the judge overseeing the sprawling case.

The children's lawyers also have complained that attorneys for cities and counties spearheading the lawsuit have refused to let them take part in settlement negotiations. The lawyers insist that a settlement or verdict must yield billions of dollars earmarked for yearslong monitoring of the physical and mental health of children born with "neonatal abstinence syndrome." That is the formal name for the cluster of symptoms endured by babies who undergo withdrawal from opioids in the days after birth.

Without that guarantee, the lawyers say cities and towns are likely to spend any money they receive from drug companies on more popular needs, as some states did with windfalls from the $206 billion settlement with tobacco companies two decades ago.

"Our goal is to make sure that we do not have a tobacco-style settlement, where all of the money goes to the governmental entities and there's not a significant trust set aside to help these children," said Stuart Smith, one of the lawyers representing the families.

About 2,000 plaintiffs, most of them cities and counties, have sued about two dozen drug companies over culpability for the prescription opioid epidemic, which has killed about 200,000 people in two decades. The cases were consolidated in a Cleveland federal court, where Judge Dan Aaron Polster is overseeing them.

Polster has encouraged the hundreds of lawyers involved to work out a mass settlement. If that does not happen, a test-case trial involving two Ohio counties, Cuyahoga and Summit, would begin later this month.

Separately, nearly every state has sued drug companies in their own courts, reasoning that they have the advantage there.

In December, Polster rejected a request for a separate "track," or trial, for the neonatal abstinence syndrome children, a status he has given to American Indian tribes. He instructed their attorneys to instead meet with top plaintiff lawyers from cities and counties "to address how [the children's] needs might be more adequately addressed."

Attorneys for the cities, counties and other groups said they supported the decision. "Judge Polster decided not to create this separate track and we believe his decision was correct," they said.

In July, the lawyers for the cities and counties also submitted consultants' reports that name pregnant women and newborns as a "special population" of people affected by opioids that would be aided by money from any verdict or settlement — signaling that they are including those groups in their overall strategy. They estimated that those two groups alone would need $10.7 billion over 10 years to remedy the damage caused by mothers' opioid use.

Now, with time running out, the attorneys for the children have sought a delay to review 130 million pages of documents and other data. Their goal is to certify the infants as a class later this year and bring a class-action suit against drug companies under the auspices of Polster and the larger litigation.

An estimated 32,000 babies were born with the withdrawal syndrome in 2014 — about one every 15 minutes, according to the National Institute on Drug Abuse. That is a more than fivefold increase from 2004.

The infants are prone to low birth weights and suffer trembling, irritability, gastrointestinal problems and sleep dysfunction, among other symptoms. They can have seizures unless they are carefully weaned off drugs by health care providers.

Research on the long-term effects is limited, but some experts are concerned that the children will suffer cognitive, developmental and behavioral problems from the effects of exposure to opioids and withdrawal.

The track record of states that received money from the tobacco settlement is at the core of the concerns expressed by the infants' attorneys. In December, a coalition of health care groups reported that states were using only a small portion of their annual payment from the tobacco case settlement to fund smoking prevention and cessation programs. The states were set to receive $9 billion from the settlement in 2019 and planned to spend $655 million on those programs, health groups said.

Smith said he fears a similar outcome if the courts don't dedicate funds for children born with the withdrawal syndrome. "Who is going to take care of these children? How are they going to get the educational, medical and psychological care they need, and who's going to pay for it?" he asked.