The quality of fetal arm movements as indicators of fetal stress

Background
Although a number of studies have found that maternal stress affects the fetus, it is unclear whether jerky fetal movements observed on ultrasound scans are indicative of fetal stress, or whether they are part of normal development.

Aims
The present study was designed to examine the relationship between jerky fetal arm movements in relation to fetal age and stress.

Methods
Video recordings were made of routine ultrasound scans of 57 fetuses (age range 8 to 33 weeks) classified into three age groups: 1st trimester (8–12 weeks, N = 9), 2nd trimester (13–24 weeks, N = 38), and 3rd trimester (26–33 weeks, N = 10). Following previous research on stress behaviour in neonates, a fetal index of stress was derived from frequency of hiccup, back arch and rhythmical mouthing.

Results
Results indicated that while stress level was unrelated to fetal age, jerkiness of arm movements was significantly associated with the fetal stress index but not age.

Conclusions
Our findings suggest that jerky arm movements in fetuses are suggestive of fetal stress.