Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started
My Medicine

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Health & Pregnancy

Font Size

New Earlier, Noninvasive Paternity Test Developed

Experts Say the Test Has Important Medical, Legal Applications

Finding Fetal DNA in Mom's Blood continued...

The first is that while researchers have long known that fetal DNA is present in the mother's blood, they believed it was floating around in such tiny amounts that it was almost impossible to find and analyze.

One of the reasons it was thought to be so rare, says researcher Ravinder Dhallan, MD, PhD, chairman and chief executive of Ravgen Diagnostics in Columbia, Md., is that the mother's blood cells easily burst when blood samples are drawn, which dilutes the fetal DNA.

By mixing a fixative agent into the blood sample, Dhallan says he was able to isolate enough fetal DNA so that it could be tested.

"What we realized was that if you add any fixative, it makes the mother's white blood cells, instead of being like water balloons that easily burst, they become more like ping pong balls that are stiff and won't burst," says Dhallan. "Now you've got 25% fetal DNA instead of 1% fetal DNA" in the blood.

By looking at the baby's DNA, researchers are able to spot places where the gene sequences are different from the mother's by only one letter. That letter will match the father's DNA. A sample of DNA from a suspected father can then confirm or exclude paternity.

When researchers tested 30 blood samples from biologic mothers and fathers who were grouped with unrelated men, they say they were able to correctly identify paternity in every case.

According to Ravgen's web site, the technology was used in 2009 to help prove that Michael A. Roseboro, who was on trial for his wife's murder, had fathered a baby with another woman. Prosecutors argued that the affair was motive for the murder.

Dhallen says he was motivated to develop the paternity test after being contacted by women who were eager to prove paternity and uncertain about whether to continue their pregnancies after situations involving violence, including rape.

"There are so many situations where people need to identify the paternity before the baby is born that are social, medical, and legal," he says.

1 | 2

Pregnancy Week-By-Week Newsletter

Delivered right to your inbox, get pictures and facts on
what to expect each week of your pregnancy.

Today on WebMD

hand circling date on calendar
Track your most fertile days.
woman looking at ultrasound
Week-by-week pregnancy guide.
Pretty pregnant woman timing contaction pains
The signs to watch out for.
pregnant woman in hospital
Are there ways to do it naturally?
slideshow fetal development
pregnancy first trimester warning signs
What Causes Bipolar
Woman trying on dress in store
pregnant woman
Woman looking at pregnancy test
calendar and baby buggy
dark chocolate squares