Sex-specific associations between maternal pregnancy-specific anxiety and newborn amygdalar volumes - preliminary findings from the FinnBrain Birth Cohort Study

Previous literature links maternal pregnancy-specific anxiety (PSA) with later difficulties in child emotional and social cognition as well as memory, functions closely related to the amygdala and the hippocampus. Some evidence also suggests that PSA affects child amygdalar volumes in a sex-dependent way. However, no studies investigating the associations between PSA and newborn amygdalar and hippocampal volumes have been reported. We investigated the associations between PSA and newborn amygdalar and hippocampal volumes and whether associations are sex-specific in 122 healthy newborns (68 males/54 females) scanned at 2-5 weeks postpartum. PSA was measured at gestational week 24 with the Pregnancy-Related Anxiety Questionnaire Revised 2 (PRAQ-R2). The associations were analyzed with linear regression controlling for confounding variables. PSA was associated positively with left amygdalar volume in girls, but no significant main effect was found in the whole group or in boys. No significant main or sex-specific effect was found for hippocampal volumes. Although this was an exploratory study, the findings suggest a sexually dimorphic association of mid-pregnancy PSA with newborn amygdalar volumes.

Secondary Increase of Lactate Levels in Asphyxiated Newborns during Hypothermia Treatment: Reflect of Suboptimal Hemodynamics (A Case Series and Review of the Literature)

Objective To evaluate whether a secondary increase of serum lactate levels in asphyxiated newborns during hypothermia treatment may reflect suboptimal dynamics. Methods-Retrospective case series and review of the literature. We present the clinical course of four asphyxiated newborns treated with hypothermia who presented with hypotension requiring inotropic support, and who displayed a secondary increase of serum lactate levels during hypothermia treatment. Serial serum lactate levels are correlated with blood pressure and inotropic support within the first 96 hours of life. Results Lactate levels initially decreased in the four patients. However, each of them started to present lower blood pressure, and lactate levels started to increase again. Inotropic support was started to raise blood pressure. The introduction of an epinephrine drip consistently worsened the increase of lactate levels in these newborns, whereas dopamine and dobutamine enabled the clearance of lactate in addition to raising the blood pressure. Rewarming was associated with hemodynamics perturbations (a decrease of blood pressure and/or an increase of lactate levels) in the three newborns who survived. Conclusions Lactate levels during the first 4 days of life should be followed as a potential marker for suboptimal hemodynamic status in term asphyxiated newborns treated with hypothermia, for whom the maintenance of homeostasis during hypothermia treatment is of utmost importance to alleviate brain injury.

Effect of persistent pulmonary hypertension on brain oxygenation in asphyxiated term newborns treated with hypothermia

OBJECTIVE

To better understand the impact of persistent pulmonary hypertension (PPHN) on brain oxygenation in term asphyxiated newborns treated with hypothermia.

METHODS

The regional cerebral oxygenation saturation (rSO2) measured by near-infrared spectroscopy was compared to pre/post-ductal oxygen saturation and mean arterial blood pressure in three term asphyxiated newborns with documented PPHN during their first 4 days of life while they were being treated with hypothermia.

RESULTS

The cerebral oxygen saturation remained relatively stable when oxygen saturation was more than 92% and when there was no difference between pre- and post-ductal oxygen saturations. Episodes of desaturations with a difference between pre- and post-ductal saturations, as well as episodes of hypotension, caused a significant decrease in rSO2 in these newborns.

CONCLUSION

This case series demonstrates that PPHN has a profound impact on brain oxygenation in term asphyxiated newborns treated with hypothermia during the first days of life after birth. PPHN may represent an additional risk factor for brain injury in these newborns during the first days of life.

Developmental dynamics of neurotensin binding sites in the human hypothalamus during the first postnatal year

The aim of the present study was to determine a detailed mapping of neurotensin (NT) in the human hypothalamus, during the first postnatal year using an in vitro quantitative autoradiography technique and the selective radioligand monoiodo-Tyr3-NT. Ten human postmortem hypothalami obtained from control neonates and infants (aged from 2 h to 1 year of postnatal age) were used. The biochemical kinetics of the binding in all obtained in this study revealed that the binding affinity constants were of high affinity (in the nanomolar range) and did not differ significantly between all cases investigated. Furthermore, competition experiments show insensitivity to levocabastine and were in favor of the presence of the high affinity site of NT receptor. Autoradiographic distribution showed that NT binding sites were widely distributed throughout the rostrocaudal extent of the hypothalamus. However, the distribution of NT binding sites was not homogenous and regional variations exist. In general, the highest densities were mainly present in the anterior hypothalamic level, particularly in the preoptic area. High NT binding site densities are also present at the mediobasal hypothalamic level, particularly in the paraventricular, parafornical, and dorsomedial nuclei. At the posterior level, low to very low densities could be observed in all the mammillary complex subdivisions, as well as the posterior hypothalamic area. Although this topographical distribution is almost identical during the postnatal period analyzed, age-related variations exist in discrete structures of the hypothalamus. The densities were higher in neonates/less aged infants than older infants in preoptic area (medial and lateral parts). The developmental profile is characterized by a progressive decrease from the neonate period to 1 year of postnatal age with a tendency to reach adult levels. On the other hand, the low levels of NT binding sites observed in posterior hypothalamus did not vary during the first postnatal year. They contrast in that with the very high levels we reported previously in adult. In conclusion, the present study demonstrates the occurrence of high NT binding sites density in various structures in many regions in the human neonate/infant hypothalamus, involved in the control of neuroendocrine and/or neurovegetative functions.

Risk factors for intraventricular hemorrhage in term asphyxiated newborns treated with hypothermia

BACKGROUND

Intraventricular hemorrhage is rare in term newborns. Severe asphyxia is recognized as one of the risk factors of intraventricular hemorrhage in these newborns. Therapeutic hypothermia, which is the only available treatment for the limitation of brain injury in term asphyxiated newborns, may cause fluctuations of cerebral blood flow, possibly placing the newborn more at risk for intraventricular hemorrhage. The literature regarding the incidence of intraventricular hemorrhage in the context of neonatal hypoxic-ischemic encephalopathy and hypothermia is sparse.

METHODS

We present a clinical observation and review the literature regarding the risk factors for intraventricular hemorrhage in term asphyxiated newborns treated with hypothermia.

RESULTS

We describe the clinical course of a term newborn with severe hypoxic-ischemic encephalopathy who developed significant intraventricular hemorrhage during the rewarming period after the 72-hour hypothermia.

CONCLUSION

This newborn presented several risk factors for intraventricular hemorrhage, including severe asphyxia, hemodynamic instability, hemostasis disturbances, instrument delivery, venous sinus thrombosis, and hypoglycemia. Hypothermia and rewarming also may have contributed by causing fluctuations in cerebral blood flow.

Early versus late MRI in asphyxiated newborns treated with hypothermia

OBJECTIVE

The purposes of this feasibility study were to assess: (1) the potential utility of early brain MRI in asphyxiated newborns treated with hypothermia; (2) whether early MRI predicts later brain injury observed in these newborns after hypothermia has been completed; and (3) whether early MRI indicators of brain injury in these newborns represent reversible changes.

PATIENTS AND METHODS

All consecutive asphyxiated term newborns meeting the criteria for therapeutic hypothermia were enrolled prospectively. Each newborn underwent one or two early MRI scans while receiving hypothermia, on day of life (DOL) 1 and DOL 2-3 and also one or two late MRI scans on DOL 8-13 and at 1 month of age.

RESULTS

37 MRI scans were obtained in 12 asphyxiated neonates treated with induced hypothermia. Four newborns developed MRI evidence of brain injury, already visible on early MRI scans. The remaining eight newborns did not develop significant MRI evidence of brain injury on any of the MRI scans. In addition, two patients displayed unexpected findings on early MRIs, leading to early termination of hypothermia treatment.

CONCLUSIONS

MRI scans obtained on DOL 2-3 during hypothermia seem to predict later brain injuries in asphyxiated newborns. Brain injuries identified during this early time appear to represent irreversible changes. Early MRI scans might also be useful to demonstrate unexpected findings not related to hypoxic-ischaemic encephalopathy, which could potentially be exacerbated by induced hypothermia. Additional studies with larger numbers of patients will be useful to confirm these results.