Sinusoidal fetal heart rate. Ominous or benign?

The perinatal prognosis associated with the sinusoidal heart rate pattern (SHR) remains controversial. Twenty-nine cases of SHR from 670 fetal heart rate tracings were correlated with narcotic analgesic use and perinatal outcome. Twenty-five of the SHR patterns followed either alphaprodine or demerol use; four were spontaneous. All neonates had Apgar scores of greater than 7 at five minutes. The prognosis of drug-related SHR is benign.