title: Correlation between regular mouthing movements and heart rate patterns during non-rapid eye movement periods in normal human fetuses between 32 and 40 weeks of gestation.
abstract: BACKGROUND
  Regular mouthing movements (RMMs) are observed during fetal non-rapid eye movement (NREM) periods.
  
  
  OBJECTIVE
  To determine the correlation between RMM and fetal heart rate (FHR) patterns during NREM periods.
  
  
  METHODS
  Fetal eye and mouth movements and FHR patterns were observed and recorded.
  
  
  METHODS
  50 normal singleton pregnancies between 32 and 40 weeks of gestation.
  
  
  METHODS
  Changes in the power spectrum ratio of 3-minute blocks of RMM clusters, FHR with RMM clusters (HR+), and FHR without RMM clusters (HR-) were calculated at a frequency band of 0.02 Hz among 3 gestational age groups: group 1, 32-34 weeks gestation; group 2, 35-37 weeks gestation; group 3, 38-40 weeks gestation. We calculated the percentage of cases showing dominant peak ratios of RMM and HR+ in the same frequency band, the maximum correlation coefficient, and its lag time.
  
  
  RESULTS
  In group 3, the dominant peaks of both RM and HR+ were present at the same frequency band, 0.06-0.08 Hz; this was not seen in the other groups' relative power spectral patterns. The percentage of cases showing dominant peaks of RMM and HR+ in the same frequency band increased with advancing gestational age. The maximum correlation coefficient in groups 1 (0.28 ± 0.11) and 3 (0.45 ± 0.14) differed significantly (p<0.05).
  
  
  CONCLUSIONS
  The correlation between RMM and FHR patterns became stronger, and their rhythmicity was similar, from 38 to 40 gestational weeks, suggesting that a common center starts to govern both patterns at approximately 38 weeks gestation.
authors: Department of Obstetrics and Gynecology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan. ohtera@med.kyushu-u.ac.jp
authors: Yuka
authors: Y
authors: Otera
authors: Seiichi
authors: S
authors: Morokuma
authors: Kotaro
authors: K
authors: Fukushima
authors: Norio
authors: N
authors: Wake
authors: Kiyoko
authors: K
authors: Kato
mesh_terms: D005133:Eye Movements; D005260:Female; D005318:Fetal Heart / Q000502:physiology*; D005324:Fetal Movement / Q000502:physiology*; D006339:Heart Rate; D006801:Humans; D008297:Male; D009055:Mouth / Q000502:physiology; D011247:Pregnancy; D011263:Pregnancy Trimester, Third / Q000502:physiology*; D012895:Sleep, REM; D016216:Ultrasonography, Prenatal