Ultrasound assessment of fetal hearing response to vibroacoustic stimulation

AUditive Direct in Utero Observation (AUDIO): A Randomized Controlled Trial for a Prenatal Demonstration of Fetal Hearing

Introduction: The objective of this randomized controlled study was to demonstrate whether acoustic stimulation in utero is associated with fetal reactivity which is documentable by cardiotocography. Materials and methods: A monocentric randomized controlled trial was performed at a single university tertiary hospital between September 2016 and July 2017. This study was registered as a randomized clinical trial on clinicaltrail.gov (registration number NCT04622059). Unselected pregnancies at term of gestation were consecutively recruited for the purpose of this study. After 10 min of normal cardiotocography without accelerations (non-stress-test with a basal frequency between 110 and 150 beats/min, normal variability between 6 and 15 b/min, no accelerations, and no fetal movements), fetuses were randomized at a 1:1 ratio to either of the two groups. Fetuses in group A (n = 105) received acoustic stimulation after 10 min from the beginning of the CTG, whereas fetuses in group B received no stimulation (n = 105). The outcome variables investigated were the lapse of time between the beginning of the CTG and the occurrence of the first acceleration, and the lapse of time between the beginning of the CTG and the first fetal movement noticed. Results: The lapse of time between the beginning of the CTG and the occurrence of the first acceleration was significantly shorter in the group with acoustic stimulation compared to the other group (14.87 ± 5.01 vs. 21.90 ± 6.94 min, p-value < 0.001 log-rank test). Similarly, the lapse of time between the beginning of the CTG and the occurrence of the first fetal movement was significantly shorter in group A compared to group B (17.77 ± 7.62 vs. 23.28 ± 7.61 min, p-value < 0.001, log-rank test). Fetal cardiac acceleration and the occurrence of a fetal movement during the first 20 min of the CTG were more frequently recorded in group A compared to group B (respectively, 15% vs. 5% and 20% vs. 8%). Conclusion: This RCT showed an early fetal reaction following auditive stimulus, documentable by cardiotocography. Further research is needed to investigate a possible role of acoustic stimulation in utero for the prenatal diagnosis of congenital hypoacusis.

Fetal Middle Cerebral Artery Pulsatility Index in No-Risk Pregnancies: Effects of Auditory Stimulation and Pregnancy Order

Pulsatility index (PI) values in a fetal middle cerebral artery (MCA) were compared in no-risk pregnancies to examine the differences related to auditory stimulation test and pregnancy order. The study included 196 women with no-risk pregnancies selected from the database of more than 1000 pregnant women divided into two groups. Group 1 consisted of 98 nulliparous women (C1 = 98) and Group 2 consisted of 98 parous women (C2 = 98). All pregnant women were of comparable age and fetal gestational age (GA) when MCA-PI values were recorded. Measurements of PI values in fetal MCA were obtained before and immediately after the application of fetal auditory stimulation test. The MCA-PI measuring was conducted in the period between the 36th and the 41st week of GA. The results showed that PI baseline values and PI values after defined auditory stimulation were significantly different when measured in nulliparous women compared to parous women (p = 0.001; p = 0.003, respectively), while no group differences were observed in relative PI value changes due to auditory stimulation. These findings suggest that hemodynamic changes in fetal MCA caused by defined auditory stimulation measured by PI value changes may be valuable in the assessment of fetal auditory perception functionality and its development.

Maternal smoking in pregnancy, fetal activity & newborn behavioral state: An observational ultrasound study

Maternal smoking during pregnancy (MSDP) remains one of the most common prenatal drug exposures in the US and worldwide. MSDP is associated with medical risk for the fetus and altered behavioral development in infants; however, fewer studies have examined the impact of MSDP on fetal behavior or newborn behavioral state. We investigated associations between MSDP and (a) fetal motor activity and (b) newborn behavioral state following handling. Participants were 79 healthy mother-fetus/newborn pairs (57% MSDP-exposed). MSDP was measured by maternal interview and verified by saliva biomarkers. Mothers completed an observational fetal ultrasound assessment between 24 and 37 weeks gestation (M = 28 weeks), including baseline, vibro-acoustic stimulus and recovery periods. Total fetal motor activity and complex body movements were coded from ultrasound videos. Following delivery, newborn post-handling behavioral state was assessed by direct observational coding. MSDP exposure was associated with higher baseline fetal motor activity, particularly at younger gestational ages. Further, motor reactivity to stimulation emerged at later gestational ages in MSDP-exposed fetuses, while motor reactivity was consistent across gestational ages in unexposed fetuses. Finally, heavy MSDP exposure was associated with more arousal following handling and greater need for soothing interventions in the newborn period. Monitoring of fetal behavior via ultrasound may offer a unique opportunity to identify at-risk infants and provides data for stronger public health messaging regarding risks of MSDP. Associations between MSDP and increased newborn fussiness highlight opportunities for education and anticipatory guidance in the postpartum period.