Plasma copeptin may not be a sensitive marker of perinatal stress in healthy full-term growth-restricted fetuses

Non-invasive monitoring of stress biomarkers in the newborn period

The neonatal period is a highly sensitive time span during which stressful experiences may have an influence on later health outcomes. Medical procedures applied to newborn babies during hospitalization are stressors that trigger a physiological and psychological stress response. Stress response has been traditionally evaluated using scores based on behavioural signs such as facial expressions, limb movements, crying, etc., which are subjectively interpreted. Only few studies have employed measurable physiological signs to objectively evaluate the stress response to specific interventions. The aim of this review is to inform of recently developed biochemical methods that allow clinicians to evaluate the stress response to medical procedures performed in the neonatal period in biological samples non-invasively obtained. Stress biomarkers are based on the physiological stress response mediated by the hypophysis-pituitary-adrenal axis and the sympathetic-adreno-medullary systems. Cortisol is at present the most widely employed laboratory determination to measure stress levels. In recent years, sequentially determined salivary cortisol levels have allowed non-invasive monitoring of newborn infants under stressful conditions in the NICU.

Maternal Nutritional and Water Homeostasis as a Presage of Fetal Birth Weight

Birth weight is a key determinant of perinatal outcomes which affect physical development and metabolic function. In this study, we evaluated the potential role of maternal body composition and nutritional status in programing fetal birth weight. This was a longitudinal study that included 29 pregnant women and their full-term newborns. Maternal dietary energy and fluid intake and body adipose tissue were assessed. In addition, we measured the serum content of copeptin, aldosterone, and angiotensin II in maternal and umbilical cord blood. The measurements were done across the three trimesters of pregnancy, on average, at 11.6 weeks, 18.3 weeks, and 30.2 weeks. Each newborn's birth weight was determined at the percentile line, using the World Health Organization (WHO) standards based on the gestational age, gender, and weight. We found no appreciable relation of fetal birth weight to the maternal dietary and fluid intakes, and the content of angiotensin II, aldosterone, or copeptin. However, birth weight correlated with increases in body adipose tissue in early pregnancy stages. Further, birth weight correlated positively with copeptin and adversely with angiotensin II in cord blood. We conclude that the present findings may be helpful in the assessment of a critical level of body adipose tissue in women of child-bearing age, above which the potential risk of macrosomia appears. The female population of child-bearing age needs a continual update on the nutritional knowledge to prevent modifiable maternal and fetal perinatal complications.

Colostrum and mature breast milk analysis of serum irisin and sterol regulatory element-binding proteins-1c in gestational diabetes mellitus

Background: We aimed to evaluate irisin and SREBP-1c levels in serum, colostrum and mature breast milk in women with and without gestational diabetes (GDM); and to relate them with maternal glucose, lipid profile and weight status of babies. Methods: GDM positive women (n = 33) and normal glucose tolerant women (NGT) (n = 33) were recruited. Maternal blood samples were collected at 28th week of gestation and later at 6-week post-partum while breast milk samples of the lactating mothers were collected within 72 hours of birth (colostrum) and at 6 weeks post-partum (mature milk). Irisin and SREBP-1c levels were analyzed by commercially available ELISA kits for all maternal samples. Results: Lower levels of irisin were seen in serum, colostrum and mature breast milk of GDM females (p < .01). SREBP-1c profile showed a similar trend of low serum levels in GDM, however, they were undetectable in colostrum and mature breast milk. Weak to moderate correlations of serum irisin with BMI (r = 0.439; p < .001), GTT 0 hours (r = 0.403; p = .01), HbA1c (r = -0.312; p = .011), Fasting blood glucose (r = 0.992; p = .008), and baby weight at birth (r = 0.486; p < .001). Colostrum and mature breast milk irisin showed positive associations with baby weight at 6 weeks (r = 0.325; p = .017; r = 0.296; p = .022, respectively). Serum SREBP-1c at 6 weeks correlated with random blood glucose (r = 0.318; p = .009), and HbA1c (r= -0.292; p = .011). All correlations were lost once we adjusted for maternal BMI. Conclusions: Low irisin and SREBP1-c levels may favor development of GDM in pregnant subjects. Further, low mature breast milk levels may act as a continued stressor from fetal to infant life as long as breast-feeding is continued. Further studies are required to identify the mechanistic relationship between these biomarkers and GDM.

Arginine Vasopressin and Copeptin in Perinatology

Arginine vasopressin (AVP) plays a major role in the homeostasis of fluid balance, vascular tonus, and the regulation of the endocrine stress response. The measurement of AVP levels is difficult due to its short half-life and laborious method of detection. Copeptin is a more stable peptide derived from the same precursor molecule, is released in an equimolar ratio to AVP, and has a very similar response to osmotic, hemodynamic, and stress-related stimuli. In fact, copeptin has been propagated as surrogate marker to indirectly determine circulating AVP concentrations in various conditions. Here, we present an overview of the current knowledge on AVP and copeptin in perinatology with a particular focus on the baby's transition from placenta to lung breathing. We performed a systematic review of the literature on fetal stress hormone levels, including norepinephrine, cortisol, AVP, and copeptin, in regard to birth stress. Finally, diagnostic and therapeutic options for copeptin measurement and AVP functions are discussed.