MAMA-2B Helps Pregnant Women Buckle Up Safely

A high-tech, pregnant crash-test dummy called MAMA-2B — for Maternal Anthropomorphic Measurement Apparatus, version 2B — is helping U-M physicians and scientists learn more about how to protect a pregnant woman and her unborn fetus during an automobile crash.

Designed by engineers at the U-M Transportation Research Institute (UMTRI), First Technology Safety Systems and Mark Pearlman, M.D., the S. Jan Behrman Professor of Reproductive Medicine in the U-M Medical School, MAMA-2B represents a 30-week pregnant woman and contains sophisticated instrumentation to relate its response in crashes at different speeds and under varying conditions to the likelihood of adverse fetal outcome.

MAMA-2B is part of a multi-phase long-term research study of automotive safety during pregnancy. Results show that good fetal outcomes are more likely to occur when the mother uses correctly positioned lap and shoulder seat belts.

"Creating this dummy was particularly interesting because of the unique anthropometry of a pregnant woman," says Pearlman, who also is vice chair of obstetrics and gynecology and an associate professor of surgery. "The limited amount of biomechanical data available on injury in pregnant women also presented a challenge." Pressure measures in the fluid-filled abdomen component, he says, are related to the risk of adverse fetal outcome.

"We estimate that between one and two percent of motor-vehicle crashes during pregnancy may result in an adverse fetal outcome, including fetal death," says Pearlman. The most common cause of fetal death in a motor-vehicle crash is from abruptio placentae. This occurs when the placenta, which supplies nutrients and oxygen to the fetus, prematurely separates from the uterine wall.

Associated projects that supported development of the MAMA-2B included investigations of 43 actual vehicle crashes involving pregnant women. "Examining real-world crashes lets us review how restraints are working to prevent injuries in the field," according to Pearlman. Another project examined how belt fit and seated anthropometry change over the course of pregnancy.

Pearlman recommends that expectant mothers sit in an automobile seat equipped with both a lap belt and a shoulder belt. "If there is no other available restraint system, a lap belt is better than no belt at all," he says. Don't disconnect the air bag, adds Pearlman, but tilt the steering wheel up toward the face and chest, so the bag is not pointed directly at the abdomen.

To properly protect themselves while driving, expectant mothers should wear the lap belt positioned underneath the bulge of pregnancy, so it can load through the pelvis and not the fetus, says Pearlman. The shoulder belt should ride along the side of the uterus, between the breasts and over the mid-portion of the collarbone. This will leave the pregnancy bulge with as little lap belt or shoulder belt over it as possible and restrain the mother and fetus — preventing the mother from crashing into the steering wheel, dashboard and windshield or being thrown from the car.

Pearlman emphasizes that if a pregnant woman is involved in a motor-vehicle crash, even a minor one, she should contact her obstetrician or nurse-midwife as soon as possible, especially if the trauma occurs in the second or third trimester of pregnancy.

Members of the research team include Lawrence Schneider, Ph.D., a senior research scientist at UMTRI; Jonathan Rupp and Kathleen Klinich, research engineers at UMTRI; and James Ashton-Miller, Ph.D., senior research scientist in the College of Engineering.

-Krista Hopson

Read a related story online at:
www.med.umich.edu/opm/newspage/pregtrauma.htm

For more information on Mark Pearlman and his research, go to:
www.med.umich.edu/obgyn/fachompg/pearlman.html

To learn more about health and safety during pregnancy, visit:
www.smartmoms.org/health-safety/index.html