An Evidence-Based Discussion of Fetal Pain and Stress.

BACKGROUND: The concept of fetal pain results from procedures conducted without anesthesia in preterm newborns and fetuses, which indicate that it is possible to examine fetal pain based on stress hormone, metabolic, and behavioral changes. Anatomical and physiological data suggest that fetuses become capable of processing nociceptive stimuli around midgestation, although the associated changes in fetal brain development remain unclear. What constitutes fetal pain remains controversial in the light of the definition of pain adopted by the International Association for the Study of Pain (IASP), which posits pain as an "unpleasant sensory and emotional experience." SUMMARY: Here, we examine the notion that human fetuses cannot "experience" pain and potential implications of this claim. We highlight the key scientific evidence related to fetal pain, including clinical studies on pain in fetuses and preterm newborns. We argue that consistent patterns of stress hormones, metabolic changes, body movements, hemodynamic changes, and pain-related facial expressions in fetuses exposed to invasive procedures overcome the need for subjective proof of pain as articulated in the IASP definition. No study to date has conclusively proven the absence of fetal pain beyond the age of viability. KEY MESSAGES: Based on the current evidence, we propose that all fetuses receive anesthesia regardless of the invasive procedures being performed to guarantee the least possible pain and physiological, behavioral, or hormonal responses without exposing the mother or her baby to unnecessary complications.

Association of Continuous Opioids and/or Midazolam During Early Mechanical Ventilation with Survival and Sensorimotor Outcomes at Age 2 Years in Premature Infants: Results from the French Prospective National EPIPAGE 2 Cohort.

OBJECTIVE: To evaluate the association of early continuous infusions of opioids and/or midazolam with survival and sensorimotor outcomes at age 2 years in very premature infants who were ventilated. STUDY DESIGN: This national observational study included premature infants born before 32 weeks of gestation intubated within 1 hour after birth and still intubated at 24 hours from the French EPIPAGE 2 cohort. Infants only treated with bolus were excluded. Treated infants received continuous opioid and/or midazolam infusion started before 7 days of life and before the first extubation. Naive infants did not receive these treatments before the first extubation, or received them after the first week of life, or never received them. This study compared treated (n = 450) vs naive (n = 472) infants by using inverse probability of treatment weighting after multiple imputation in chained equations. The primary outcomes were survival and survival without moderate or severe neuromotor or sensory impairment at age 2 years. RESULTS: Survival at age 2 years was significantly higher in the treated group (92.5% vs 87.9%, risk difference, 4.7%; 95% CI, 0.3-9.1; P = .037), but treated and naive infants did not significantly differ for survival without moderate or severe neuromotor or sensory impairment (86.6% vs 81.3%; risk difference, 5.3%; 95% CI -0.3 to 11.0; P = .063). These results were confirmed by sensitivity analyses using 5 alternative models. CONCLUSIONS: Continuous opioid and/or midazolam infusions in very premature infants during initial mechanical ventilation that continued past 24 hours of life were associated with improved survival without any difference in moderate or severe sensorimotor impairments at age 2 years.

Inverse Relationship between Cardio-Ankle Vascular Index and Body Mass Index in Healthy Children.

OBJECTIVE: To establish reference scores for cardio-ankle vascular index (CAVI), a noninvasive measure of vascular function, which reflects the stiffness of arteries, in healthy children, to test for racial and ethnic differences, and to compare CAVI scores between overweight and normal weight children. STUDY DESIGN: Subjects included 292 children aged 10-18 years: 100 non-Hispanic whites, 89 non-Hispanic blacks, and 103 Hispanics. Subjects were grouped as normal weight (body mass index [BMI] <85th percentile for age) and overweight (BMI >85th percentile for age). Blood pressure (BP) and CAVI scores were measured in all subjects. RESULTS: After controlling for age, sex, and BMI, normal weight black males had a higher CAVI score (indicating stiffer arteries) in comparison with Hispanic males and white males (5.53 ± 0.15 vs 5.13 ± 0.15 vs 5.02 ± 0.15, P = .04). BMI had an inverse association on the CAVI score (r = -0.335, P < .0001). In multivariable analysis, BMI and average CAVI scores were significant predictors of each other (R(2) = 0.37, P < .0001, R(2) = 0.21, P < .0001). There was no significant correlation between CAVI scores and resting BP values, confirming that CAVI scores were independent of concurrent BP values. CONCLUSIONS: Significant differences in vascular function exist among ethnic groups of children. Overweight children had lower CAVI scores, suggestive of vascular adaptation to obesity in early life. CAVI, by providing a noninvasive measure of vascular health, may help identify children at increased risk for cardiovascular disease.

Early adversity, socioemotional development, and stress in urban 1-year-old children.

OBJECTIVE: To determine demographic, maternal, and child factors associated with socioemotional (SE) problems and chronic stress in 1-year-old children. STUDY DESIGN: This was a prospective, longitudinal, community-based study, which followed mother-infant dyads (n = 1070; representative of race, education, and income status of Memphis/Shelby County, Tennessee) from midgestation into early childhood. Child SE development was measured using the Brief Infant-Toddler Social and Emotional Assessment in all 1097 1-year-olds. Chronic stress was assessed by hair cortisol in a subsample of 1-year-olds (n = 297). Multivariate regression models were developed to predict SE problems and hair cortisol levels. RESULTS: More black mothers than white mothers reported SE problems in their 1-year-olds (32.9% vs 10.2%; P < .001). In multivariate regression, SE problems in blacks were predicted by lower maternal education, greater parenting stress and maternal psychological distress, and higher cyclothymic personality score. In whites, predictors of SE problems were Medicaid insurance, higher maternal depression score at 1 year, greater parenting stress and maternal psychological distress, higher dysthymic personality score, and male sex. SE problem scores were associated with higher hair cortisol levels (P = .01). Blacks had higher hair cortisol levels than whites (P < .001). In the entire subsample, increased hair cortisol levels were associated with higher parenting stress (P = .001), lower maternal depression score (P = .01), lower birth length (P < .001), and greater length at 1 year of age (P = .003). CONCLUSION: Differences in maternal education, insurance, mental health, and early stress may disrupt SE development in children. Complex relationships between hair cortisol level in 1-year-olds and maternal parenting stress and depression symptoms suggest dysregulation of the child's hypothalamic-pituitary-adrenal axis.