Relationship between the Duration of Fetal Breathing Movements and Gestational Age and the Development ofthe Central Nervous System at 25–32 Weeks of Gestation in Normal Pregnancy

Abstract

In 15 pregnant women with normal pregnancy at 25–32 weeks of gestation, fetal breathing movements (FBM), fetal body movements and fetal heart rate were continuously and simultaneously recorded over a total period of 180 min. The frequency of successive FBM with a duration < 10 s (apnea period > 3 s) showed a significant decrease (p < 0.01), while the frequency of successive FBM with a duration ≥ 30 s showed a significant increase from 25 to 32 weeks of gestation (p < 0.001). Strong positive correlations were also demonstrated between the frequency of FBM with a duration of ≥ 30 s and the number of fetal heart rate accelerations per hour, acceleration/ fetal body movement ratio, and the value of fetal heart rate long-term variability. These results suggest that the length of the duration of successive FBM represents a useful parameter for the analysis of fetal respiratory patterns, and that a prolongation of the duration of successive FBM of an individual fetus is related to the functional development of the central nervous system.

Relationship of Fetal Breathing Movement Pattern to Surfactant Phospholipid Levels in Amniotic Fluid and Postnatal Respiratory Complications

“…It was demonstrated that there was a signifi cant correlation between the maturation of the fetal breathing pattern and the incidence of neonatal respira tory complications in 121 pregnancies. However, only 40 of the patients studied were women who had premature delivery, and we have recently found that the frequency of successive breathing movements with a duration of 30 s or more shows a significant increase as pregnancy advances [9], In the present study, we, therefore, classi fied fetal breathing patterns into three types according to the presence or absence of breathing movements and the duration of successive respiratory movements. Only pregnant women who eventually underwent preterm birth were chosen as subjects.…”

Scaling analysis of paces of fetal breathing, gross-body and extremity movements

“…It has been shown from the observations made over 24 hr that at 24-28 weeks of gestation, fetuses breathe about 14 % of the time [16] and by 34 to 40 weeks breathing increases to about 30% of the time [17]. From 25 to 32 weeks, episodes of shorter breaths decrease and those lasting for more than 30 s increase [18]. Episodic breathing is interspersed with apnoeic periods whose duration varies with the gestational age.…”

Evaluación de las interacciones cardiorespiratorias fetales en la restricción del crecimiento intrauterino

“…Aunque la coincidencia de una señal con complejos QRS fetales con una relación señal a ruido apropiada y la presencia de MRF por periodos mayores a 4.6. Limitaciones 42 30s restringieron el número final de casos disponible para análisis, esa ventana de tiempo elimina diferencias potenciales que pudieran influir debido a la maduración o al estado fetal [107]. En consecuencia, se analizó un grupo muy selecto en términos de edad gestacional (32-37 semanas), peso estimado (< percentil 3) e índices hemodinámicos, y fue posible estudiar como es que la ASR modifica a la frecuencia cardiaca durante los MRF en el caso específico de RCF sin alteraciones hemodinámicas Doppler.…”

“…Se analizó el vector de tiempos de MRF con el fin de localizar segmentos de 30 s con presencia de movimientos respiratorios. Esta duración se estableció con base en el desarrollo del sistema nervioso central de fetos sanos, como sugirió Higuchi et al [107], y de igual forma procurando mantener el mismo intervalo [143]. De esta forma se generó un nuevo vector de tiempos con base en la ubicación temporal de los fotogramas correspondientes a cada inicio inspiratorio dentro del segmento estudiado.…”

“…Proporción de los MRF en RCF: El estudio de la proporción de los MRF durante la evolución de la RCF podría constituir un indicador del nivel de regulación autonómica, debido a que la presencia y ritmo de los MRF implican integridad neuromuscular y madurez de los mecanismos involucrados, tal como sí se ha reportado para fetos de bajo riesgo [107]. Fetal Growth Restriction (FGR) is an evolving circulatory entity [1][2][3][4] and, occasionally, in the first stages it is manifested even when there is no evidence of hemodynamic alterations in the Doppler evaluation [5,6].…”