Fetal testing can reduce stillbirths in older moms

Fetal testing can reduce stillbirths in older moms
By Joi Preciphs
Copyright © 2007, Chicago Tribune and Bloomberg News
Published February 14, 2007

Testing mothers older than 40 for fetal distress at 38 weeks significantly reduced stillbirth rates, according to a study of U.S. government data.

Fetal monitoring had greater effect in reducing the number of stillborn babies in older mothers, who are also at greater risk for stillbirths than those younger than 35, the analysis showed. The study, presented at a meeting Saturday, looked at women with no pre-existing complications who carried their babies to at least 38 weeks. Forty weeks is considered full term.

"The cumulative risk of stillbirth at 38 weeks in an uncomplicated patient over 40 is similar to the risk of stillbirth at 41 weeks in an uncomplicated patient who is less than 35 years old," said lead researcher Mert Ozan Bahtiyar, an associate professor at the Yale School of Medicine, in the study.

Fetal distress and a prolonged second stage of labor are more common in older women, according to the March of Dimes, a non-profit organization that supports treatments for birth defects. Older women also are at higher risk for developing high blood pressure and diabetes during pregnancy.

Bahtiyar and colleagues examined death statistics from the Centers for Disease Control and Prevention of more than 11 million individual deliveries between 1995 and 1997. The women in the study ranged from 15 to 44 years of age and were at least 37 weeks pregnant.

Using a mathematical model, the researchers calculated the number of late-stage pregnancy tests needed for each age group to prevent one stillbirth. The tests usually consist of monitoring the heart rate and other biological indicators.

The model suggests that for women ages 35 to 39, initiation of fetal testing at 38 weeks would require at least 1,717 late-stage pregnancy surveillance tests to be performed by 40 weeks of pregnancy to prevent one stillbirth. For women ages 40 to 44, just 494 tests would be required to prevent a similar event from occurring by 40 weeks, the study said.

Early prenatal testing is usually recommended to women older than 35 to screen for conditions such as Down syndrome, a genetic condition associated with mental retardation. Fetal stress testing is typically reserved for women with complications or a prior history of complications during pregnancy, Bahtiyar said in a telephone interview.

Bahtiyar presented an abstract of the study at the Society for Maternal-Fetal Medicine's annual meeting in San Francisco.