Comparison of fetal behavior in low- and high-risk pregnancies

Fetal Development: Voice Processing in Normotensive and Hypertensive Pregnancies

Recent observation of maternal voice recognition provides evidence of rudimentary memory and learning in healthy term fetuses. However, such higher order auditory processing has not been examined in the presence of maternal hypertension, which is associated with reduced and/or impaired uteroplacental blood flow. In this study, voice processing was examined in 40 fetuses (gestational ages of 33 to 41 weeks) of hypertensive and normotensive women. Fetuses received 2 min of no sound, 2 min of a tape-recorded story read by their mothers or by a female stranger, and 2 min of no sound while fetal heart rate was recorded. Results demonstrated that fetuses in the normotensive group had heart rate accelerations during the playing of their mother's voice, whereas the response occurred in the hypertensive group following maternal voice offset. Across all fetuses, a greater fetal heart rate change was observed when the amniotic fluid index was above compared to below the median (i.e., 150 mm), indicating that amniotic fluid volume may be an independent moderator of fetal auditory sensitivity. It was concluded that differential fetal responding to the mother's voice in pregnancies complicated by maternal hypertension may reflect functional elevation of sensorineural threshold or a delay in auditory system maturation, signifying functional differences during fetal life or subtle differences in the development of the central nervous system.

Early Parental Adaptation, Prenatal Distress, and High-Risk Pregnancy

OBJECTIVES

To examine the examined the effects of high risk pregnancy and prenatal distress on parental postnatal adaptation.

METHODS

A sample of 111 expecting parents, consisting of 32 high risk pregnancy (HRP) mothers and 21 spouses and 36 matched low risk pregnancy (LRP) mothers and 22 spouses completed reports of depression symptoms (BDI) and pregnancy related concerns prenatally. At three months postpartum, parent-infant direct observations and reports of parenting alliance (PAI), stress (PSI-SF), satisfaction and efficacy (PSOC) were gathered. Data was analyzed with GLM multivariate analyses and the actor-partner interdependence model.

RESULTS

Parents' prenatal BDI predicted postnatal parental stress. BDI and concerns predicted postnatal satisfaction, but only for mothers. Mother's concerns predicted low maternal and high paternal parenting alliance. Partner effect was found so that high concerns predicted high reports of parenting alliance by spouse. Mean-group differences were found between HRP and LRP during parent-infant observations, so that HRP parents displayed lower sensitivity and reciprocity.

CONCLUSIONS

Prenatal distress, and to some degree high risk pregnancy, are risk factors that may interfere with the early formation of parent-infant relationship. Clinical implications of these findings are presented.

Functional Network Development During the First Year: Relative Sequence and Socioeconomic Correlations

The first postnatal year is characterized by the most dramatic functional network development of the human lifespan. Yet, the relative sequence of the maturation of different networks and the impact of socioeconomic status (SES) on their development during this critical period remains poorly characterized. Leveraging a large, normally developing infant sample with multiple longitudinal resting-state functional magnetic resonance imaging scans during the first year (N = 65, scanned every 3 months), we aimed to delineate the relative maturation sequence of 9 key brain functional networks and examine their SES correlations. Our results revealed a maturation sequence from primary sensorimotor/auditory to visual to attention/default-mode, and finally to executive control networks. Network-specific critical growth periods were also identified. Finally, marginally significant positive SES-brain correlations were observed at 6 months of age for both the sensorimotor and default-mode networks, indicating interesting SES effects on functional brain maturation. To the best of our knowledge, this is the first study delineating detailed longitudinal growth trajectories of all major functional networks during the first year of life and their SES correlations. Insights from this study not only improve our understanding of early brain development, but may also inform the critical periods for SES expression during infancy.

Estimated cardiac vagal tone predicts fetal responses to mother's and stranger's voices

Heart rate responses of 84 near-term fetuses to recorded female voices were examined in 166 trials of auditory stimulation. Each fetus was presented with a 2-min recording of their mother's voice and a 2-min recording of a female stranger's voice, in counterbalanced order, with a 10-min rest period between trials. High frequency heart rate variability during a 2-min baseline period was used to estimate cardiac vagal tone for each trial. Differential heart rate responses to familiar and unfamiliar voice recordings were observed during a 2-min poststimulus period, only when estimated cardiac vagal tone was high. This finding suggests that vagal tone plays a moderating role in the cardiac responses of term fetuses to familiar and unfamiliar stimuli.