By Ginger Allen

Follow CBSDFW.COM: Facebook | Twitter

DALLAS (CBS11) – If you’ve had a baby, chances are you have taken, or have at least heard of, Zofran. For decades, the anti-nausea medicine has been used to fight morning sickness in women.

READ MORE: Severe Weather Threat For North Texas Tuesday Night, Early Wednesday Morning

But, the Food and Drug Administration does not approve the drug for that use.

And, the drug maker’s own documents filed with Health Canada say it is “not recommended” for pregnant women.

Now, The I-team has learned moms nationwide are filing lawsuits against GlaxoSmithKline Inc., the manufacturer of zofran, claiming it caused serious birth defects in their babies.

Julia Shonkwiler is one of those moms. Her son, Brayden, just turned one- year- old. He is learning to sit up, and he’s mastering the army crawl; however, Shonkwiler realizes these milestones are celebrated much earlier with most babies.

“He can’t do things normal children his age can do,” says Shonkwiler.

Initially, Shonkwiler says doctors told her that Brayden had breathing and feeding problems, but the news got worse. At four months old, her pediatrician said Brayden’s head was large for his body. They had discovered fluid on his brain. Then, doctors learned how weak his heart is.

“We found out he had hydrocephalous, a thickened artery, and a heart murmur.”

Shonkwiler blames zofran. She says she took it to fight morning sickness during her pregnancy.

“I assume my doctor gave it to me so it would be ok.”

More than a dozen federal lawsuits have been filed against GlaxoSmithKline, Inc.. The lawsuits cite several recent medical studies linking Zofran to birth defects, heart problems, and cleft palate.

The FDA approved the drug to help fight nausea in cancer patients in 1991.

But for decades, it’s been widely used “off-label,” or unapproved, to treat morning sickness.

Dallas attorney Kay Van Wey is one of many attorneys now claiming GlaxoSmithKline knew about the problem as early as 1992, received reports of birth defects, and continued to market the drug for morning sickness.

“They never disclosed their animal studies or the adverse reports to the doctors or the patients,” says Van Wey. “In my view, this is a prime example of corporate greed.”

According to documents obtained by the I-Team, in 2012, GlaxoSmithKline plead guilty and paid three- billion dollars in a settlement with the United States Department of Justice. Among the allegations was promoting Zofran for off-line use and paying physicians kickbacks for prescribing it.

READ MORE: Some Tenants Say Conditions At Dallas' Highland Hills Apartments Still Unlivable Following Explosion

The I-Team has also learned in Canada, a warning on the monograph states safety “…for use in human pregnancy has not been established… Animal studies are not always predictive of human response.” It states the drug is “not recommended” in pregnancy.

However, Dallas OB/GYN Dr. Elizabeth Stevenson says she is not overly concerned. She is a mom who took Zofran during her own pregnancy and a doctor who has prescribed it for more than a decade. And, Dr. Stevenson still prescribes Zofran.

“I don’t’ think it’s a big problem right now,” says Dr. Stevenson.

She says sometimes you hear about the lawsuits before the medical alerts. “It’s interesting when we had about the lawsuits before we get anything in the medical literature.”

She says she will wait for guidance before reacting. “Most of the time we like to wait until we get a statement from the organizations that make recommendations.”

Dr. Stevenson says she’s never had a patient with a problem.

But, moms like Julia Shonkwiler, are not waiting. “I’m hurt, it seems careless,…“ she says. With her lawsuit filed, she is on a mission to alert other moms.

“Be informed. Have knowledge about the medication before you take it, because your child can suffer in the long run.”

GlaxoSmithKline filed a brief with the courts earlier this month asking to consolidate the federal lawsuits as it “anticipates more” are coming.

GlaxoSmith Kline, Inc. sent us the following statements regarding the pending litigation:

GSK has filed a motion to centralize all federal Zofran® cases in a multidistrict litigation in United States District Court for the Eastern District of Pennsylvania. This administrative action would allow for coordinating and organizing litigation, which is currently scattered across the US, closest to documents, witnesses and GSK’s co-centralized U.S. pharmaceutical operations and offices in Philadelphia.

Zofran® is indicated for the prevention of nausea and vomiting associated with chemotherapy treatment, and for the prevention of postoperative nausea and/or vomiting. This important medication has been approved by FDA for nearly 25 years as safe and effective for these indications.

GSK has not admitted wrongdoing in the marketing of Zofran® at any time.

GlaxoSmithKline sent the I-Team this statement regarding the differences between the documents filed with the Federal Drug Adminsitration in the United States and those filed with Health Canada in Canada:

Each country has its own prescription drug regulations, which include the wording it requires for labels when a drug has not been specifically approved for pregnant women. Zofran sold in Canada includes the specific wording that the Canadian government requires for such products, and Zofran sold in the United States has the language mandated under the U.S. code. (21 CFR 201.57, (6)(i)(b) and 21 CFR 201.57, (8)(ii)). Therefore, while the wording may be different, both the U.S. and Canadian labels convey a similar message and follow the law in each of these countries.

MORE NEWS: Lawlessness Once Reigned On 'Hell's Half Acre' In Downtown Fort Worth

(©2015 CBS Local Media, a division of CBS Radio Inc. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)