Perinatal outcomes after increased fetal movement as counted by a fetal movement acceleration measurement recorder.

Introduction: There is no consensus in perinatal medicine about what increased fetal movement means. Objective: Our purpose was to study the relationship between perinatal outcomes and an increase in gross fetal movement as counted by an objective method. Methods: This was a prospective cohort study. A total of 471 pregnant women recorded fetal movement with a fetal movement acceleration measurement recorder at night weekly after 28 weeks. The ratio of 10-second epochs with fetal movement to all epochs was calculated as a fetal movement parameter when movement could be recorded for more than 4 h on one night. If the parameter was above the 90th percentile on the previously made reference curve, it was defined as increased movement. Women who showed the increased fetal movement at least once were classified into a study group, and the other women were classified into a control group. Perinatal abnormalities between the two groups were compared with the Chi-square test or Fisher's exact test. Results: A total of 13,931 h were recorded from 390 women, including 74 and 316 women, respectively, in the study and control groups. There were fewer preterm births (1.4 %), non-cephalic presentations at delivery (0 %), and Cesarean deliveries (25.7 %) in the study group than in the control group (15.5 %, 6.0 %, and 39.9 %; p = 0.0003, 0.031, and 0.024, respectively). There were no significant differences in the other perinatal outcomes. Conclusion: An increase in long-term gross fetal movement has a protective effect against preterm birth, non-cephalic presentation at birth, and Cesarean delivery.