A new method for long-term home monitoring of fetal movement by pregnant women themselves

Abstract

Fetal movement is one index of fetal well-being. We designed and built a new recorder based on fetal movement acceleration measurement (FMAM). The FMAM recorder has a newly developed, capacitive acceleration sensor that can detect the oscillations of the maternal abdominal wall caused by fetal movements. In this study, the recorder was examined for its suitability for long-term home monitoring of fetal movement by pregnant women themselves. Experiment I: Fourteen pregnant women underwent 45 examinations in the laboratory at gestational 20-39 weeks. We simultaneously recorded fetal movement as detected by the recorder, ultrasonography, and maternal perception, and then calculated agreement among the three methods. We evaluated agreement using prevalence-adjusted bias-adjusted kappa (PABAK). Agreement for gross fetal movement as detected by FMAM and ultrasonography was substantial or almost perfect, while agreement between maternal perception and ultrasonography was moderate or substantial. Experiment II: Six pregnant women undertook 53 experiments at home by themselves. Fetal movement during maternal nocturnal sleep was successfully recorded 50 out of 53 times at home. In conclusion, there was high agreement for gross fetal movement between FMAM and ultrasonography. The recorder is promising for objective, accurate, and long-term home monitoring of gross fetal movement by pregnant women themselves.