In a study to be presented today at the Society for Maternal-Fetal Medicine's (SMFM) annual meeting, The Pregnancy Meeting ™, in San Francisco, researchers will present findings that prove that the use of fetal（胎儿的） heart rate monitors lowers the rate of infant mortality. There have been a handful of small studies conducted in the past that looked at the effectiveness of fetal heart rate monitors, but none of them were large enough to be conclusive（决定性的） .

"There was some criticism within the obstetric（产科的） community that fetal heart rate monitoring was quickly accepted technology without proof that it was effective," said Suneet P. Chauhan, M.D., one of the study's authors. "We thought we could use data from the National Birth Cohort to get a large enough sample to gauge（测量，估计） its effectiveness."

Chauhan and his colleagues (Han-Yang Chen, Cande Ananth, Anthony Vintzileos and Alfred Abuhamad) used a sample of 1,945,789 singleton infant birth and death records from the 2004 National Birth Cohort. Multivariable（多变量的） log-binomial regression models were fitted to estimate risk ratio to evaluate the association between electronic fetal heart rate monitoring (EFM) and mortality, while adjusting for age, race, marital status, education, smoking, and the infant's gender.

The results showed that in 2004, 89% of singleton pregnancies had EFM. EFM was associated with significantly lower infant mortality (adjusted RR 0.75; 95% CI 0.69, 0.81); this was mainly driven by the lower risk of early neonatal mortality（新生儿死亡率） (adjusted RR 0.50; 95% CI 0.44, 0.57) associated with EFM. In low-risk pregnancies, EFM was associated with decreased risk for low (< 4) 5 min Apgar scores (RR 0.54; 95% CI 0.49, 0.51), whereas in high risk pregnancies EFM was also associated with decreased risk of neonatal seizures (adjusted RR 0.65; 95% CI 0.46, 0.94).

The study demonstrates that the use of EFM decreased early neonatal mortality by 53%.