Development of fetal heart rate and behavior: indirect measures to assess the fetal nervous system

Development of integrative autonomic nervous system function: an investigation based on time correlation in fetal heart rate patterns

“…Short-time correlation increases both in quiet and active heart rate patterns. However, in fHRP I it does only accelerate after 32 weeks of gestation, probably refl ecting the emergence of Nijhuis state 1F which is known to increase in frequency and duration over the last weeks of pregnancy and seems to be an important criterion of normal Brought to you by | Karolinska Institute Authenticated Download Date | 5/31/15 7:31 PM ANS development [4,16,17,21] . Growing short-time correlation might also be associated with an increasing frequency of fetal breathing movements and respiratory sinus arrhythmia (RSA) over the second half of gestation [10,17,29,30] .…”

“…The functioning of the fetal ANS can be assessed by examining fetal heart rate patterns and/or fetal movements [5,16] . During pregnancy, the development of complex regulatory circuits building the basis of integrative ANS functions and adjusting vegetative functions to fetal behavior causes an increasing synchronization of body movements and heart rate accelerations [4,21] and leads to the emergence of four consistent behavioral states defi ned by Nijhuis et al [18] as quiet sleep (1F), active sleep (2F), quiet wakefulness (3F) and active wakefulness (4F).…”

Fetal responses to induced maternal relaxation during pregnancy

“…These measures of fetal functioning are typically referred to as neurobehaviors, develop in predictable ways over the course of gestation, and are widely regarded as indicators of the developing fetal nervous system (Hepper, 1995;James, Pillai, & Smoleniec, 1995;Maeda et al, 2006;Nijhuis & ten Hof, 1999;Yoshizato et al, 1994). In particular, fetal heart rate variability is a well-known indicator of fetal well-being (Parer, 1999), and the degree of coupling between brief acceleratory changes in fetal heart rate in response to motor activity provides an indicator of integration between neural circuits (Baser, Johnson, & Paine, 1992;DiPietro et al, 2006).…”

Physiology of Prenatal Exercise and Fetal Development

“…Fetal activity state determination is based on the fetal HR pattern, body movements, and, if available, eye movements as well (Nijhuis and Ten Hof 1999). Quiet activity states, IF and 3F, are associated with absent or few HR accelerations, low amplitude body movements, and less eye (non-REM) movements (Oppenheimer and Lewinsky 1994).…”