Association of fetal eye movement density with sleeping and developmental problems in 1.5-year-old infants.

Eye movement density (EMD) is an evaluation index of rapid eye movements observed during sleep. This study aimed to investigate the association of fetal EMD with sleeping and developmental problems in infancy. We observed 60 normal singleton pregnancies (gestational age 28-37 weeks) using ultrasonography for 1 h. Fetal eye movements were counted, and EMD was calculated. Participants answered questionnaires regarding their child's sleep and development 1.5 years after their delivery. The outcomes of an infant's sleep were night awakening (yes or no), bedtime (before or after 22:00), and nighttime sleep duration (< 9 or ≥ 9 h). An infant's development was evaluated using the Child Behavior Checklist (CBCL) T-score. We found that decreased fetal EMD was associated with increased night awakening at the age of 1.5 years (odds ratio 0.84, 95% confidence interval 0.69-1.00 per unit decrease in EMD). However, fetal EMD was not associated with bedtime or nighttime sleep duration. In addition, fetal EMD was independently associated with the total problems T-score of the CBCL at the age of 1.5 years in the multivariate model (p = 0.047). In conclusion, fetal EMD may be associated with sleep and developmental problems in infants.

A study on the association between eye movements and regular mouthing movements (RMMs) in normal fetuses between 24 to 39 weeks of gestation.

Regular Mouthing Movements (RMMs) are movements in which lips and lower jaw movements occur regularly and can be observed in the fetus using transabdominal ultrasonic tomography. In near term infants, it is known that RMMs form clusters during the quiet sleep period. The notation of RMMs is not uniform, and is described as spontaneous sucking movement or non-nutritive sucking in newborns. Non-nutritive sucking is used to evaluate neurological function after birth, but there are no fetal indicators. The purpose of this study was to clarify the changes in the RMM clusters in fetuses at 24-39 weeks of gestation, and to investigate the relationship with the non-eye movement (NEM) period, which corresponds to the quiet sleep period after birth. Subjects included 83 normal single pregnancy cases. Fetal RMMs and eye movement (EM) were observed for 60 minutes using ultrasonic tomography and recorded as moving image files. We created time series data of eye movements and mouth movements from video recordings, and calculated RMM clusters per minute within effective observation time, RMM clusters per minute in EM period, RMM clusters per minute in NEM period, mouthing movements per cluster and ratio of number of RMM clusters per minute between NEM and EM periods and analyzed using linear regression analysis. As a result, critical points were detected in at two time points, at 32-33 weeks and 36-37 weeks of gestation, in RMM clusters per minute within the effective observation time and RMM clusters per minute in NEM period, respectively. RMM clusters in human fetuses increased from 32-33 to 36-37 weeks. This change is thought to represent fetal sleep development and central nervous system development.

Simplified Wide-Range Ultrasonic Measurements Using the Sensor Three-Dimensional System.

We developed a simplified three-dimensional ultrasonic device that can scan a wide area and performed measurements in the scanned area. The system is more compact than magnetic resonance imaging (MRI) systems and can measure random cross sections by acquiring volume data over a wide range through freehand scanning with a magnetic sensor unit that detects the transducer position. The system was applied successfully to a case with a huge myoma. Our system, in ways similar to computed tomography or MRI systems, can support both the objective understanding of the pathology of huge tumors and follow-up determinations of tumor diameters at arbitrary cross sections in the volume data.

Eye movement activity in normal human fetuses between 24 and 39 weeks of gestation.

Rapid eye movement (REM) sleep occurs throughout a relatively large proportion of early development, and normal REM activity appears to be required for healthy brain development. The eye movements (EMs) observed during REM sleep are the most distinctive characteristics of this state. EMs are used as an index of neurological function postnatally, but no specific indices of EM activity exist for fetuses. We aimed to identify and characterize EM activity, particularly EM bursts suggestive of REM periods, in fetuses with a gestational age between 24 and 39 weeks. This cross-sectional study included 84 normal singleton pregnancies. Fetal EMs were monitored using real-time ultrasonography for 60 min and recorded as videos. The videos were manually converted into a time series of EM events, which were then analyzed by piecewise linear regression for various EM characteristics, including EM density, EM burst density, density of EMs in EM bursts, and continuous EM burst time. Two critical points for EM density, EM burst density, and density of EMs in EM bursts were evident at gestation weeks 28-29 and 36-37. Overall EM activity in human fetuses increased until 28-29 weeks of gestation, then again from 36-37 to 38-39 weeks of gestation. These findings may be useful for creating indices of fetal neurological function for prognostic purposes.