Does the pattern of fetal movement predict infant development?

Fetal Movement (FM) has been studied as a prenatal manifestation of activity level, a core dimension of many temperament theories. However, there has been little research exploring the significance of variability in the pattern of FM. The current study uses hierarchical linear modeling to compute the developmental function of FM in the third trimester. This study also examined how variability in the pattern of FM, in contrast to mean FM, predicted infant development. The following hypotheses were tested: 1. Mean FM will predict infant development at 3 and 6 months; 2. The developmental function of FM will display an inverted-U shape with significant variability; and 3. The pattern of FM will predict infant outcome at 3 and 6 months. Thirty-three mothers were asked to provide weekly counts of FM. Infant temperament, mental development, and motor development were assessed at 3 and 6 months. The best-fitting pattern describing FM was a piecewise linear function with FM increasing until 34 weeks gestation and thereafter decreasing, but variability was noted. The overall mean FM and pattern of FM were differentially associated with infant development. Higher mean FM was associated with increases in negative affect and decreases in orienting/regulation across 3 to 6 months. Mean FM also predicted infant size. The pattern of FM was related to different outcome variables. Increases in FM early and decreases in FM late in the third trimester were associated with less activity and greater emotional tone and attention at 3 months. This same pattern of FM was related to weighing more at 6 months, decreasing in extraversion from 3 to 6 months, and becoming more active from 3 to 6 months of age. The results indicate that the pattern of FM provides information about subsequent development that is different from mean FM. Whereas mean FM was associated with aspects of difficult temperament, the pattern of FM predicted more positive outcomes. These findings suggest that the pattern of FM may be useful as a prenatal assessment of postnatal development