Jennifer Bates undergoes an ultrasound 26 weeks
At UC Irvine Medical Center, Jennifer Bates undergoes an ultrasound 26 weeks into her pregnancy. Such exams will play a key role in UCI’s effort to establish new national standards for fetal growth. Daniel A. Anderson / University Communications

Ultrasound appointments in the early months of a pregnancy can be nerve-wracking for some women. Is the baby healthy and developing properly? Is growth on target? Is the baby underweight?

Most pregnant women don’t know that current growth standards are based on 30-year-old data that may not reflect their age, ethnicity or even where they live – all factors that affect a baby’s rate of development. This one-size-fits-all approach hinders obstetricians’ ability to calculate accurate due dates and apply precise measurement guidelines.

To remedy that, the National Institutes of Health has granted UC Irvine $1.7 million to establish more demographic-specific national standards for fetal growth. Researchers at UCI, Columbia University, Northwestern University and the Medical University of South Carolina will spend three years tracking fetal development in thousands of Caucasian, African American, Asian and Hispanic women across the country.

“Normal fetal growth is a critical part of a healthy pregnancy and affects the long-term health of the child,” says Dr. Deborah A. Wing, associate professor and director of maternal-fetal medicine in UCI’s Department of Obstetrics & Gynecology. “Establishing a national standard will revolutionize the way we practice modern obstetrics.”

Accurate fetal growth data, she says, will better enable prenatal care providers to diagnose and treat women whose babies are not developing properly.

The old data leaves many questions unanswered. For example, while obese women are predisposed to having babies large for their gestational age and Asian women tend to have smaller babies, it’s not clear at what point this may indicate a problem.

“This important investigation will redefine the degree to which a physician must react to a potential fetal growth abnormality,” Wing says.

In May, UCI researchers and colleagues at Long Beach Memorial Medical Center will begin recruiting 600 normal-weight women in the first trimester of low-risk pregnancies; 150 obese women also will be enrolled. Participants will receive prenatal care, including five ultrasound exams, and complete surveys about their eating habits.

Information from the four major racial/ethnic groups will be used to determine normal fetal growth patterns for each.

“The vision is that one day, an obstetrician will be able to plug a woman’s demographic characteristics – age, weight and ethnicity – into a computer and generate a patient-specific fetal growth curve for her baby,” Wing says.

Women interested in participating in the study can call Christine Preslicka or Bethany Vinson at 562-933-2955 or Pamela Rumney at 714-456-2217.