Salivary Cortisol as Stress Marker in Newborns Subjected to Double Weighing With Physiological Body Weight
Condition: Cortisol Overproduction
MeSH terms: Adrenocortical Hyperfunction; Body Weight
Study type: Observational

Summary: 
      According to scientific revisions, salivary cortisol is a valid method for measuring
      adrenocortical activity in newborns because it is non-invasive in fact the measurement of
      salivary cortisol has been used as a stress marker in newborns since 1992. The mechanism by
      which cortisol induces stress, concerns the hypothalamic-pituitary-adrenal axis. The
      hypothalamus produces the corticotropin-releasing hormone, which stimulates the production of
      adrenocorticotropin by hypophysis. Adrenocorticotropin induces the secretion of
      glucocorticoids such as cortisol by stimulating the cortex of the adrenal gland. An
      appropriate release of cortisol due to stress factor is vital for surviving and the loss of
      this mechanism increase the risk of morbidity and mortality for newborns. However, prolonged
      exposure to a high level of cortisol may increase the risk of cognitive and behavioural
      disorders, hypertension, hyperlipidaemia, insulin resistance, immune deficiency and
      hippocampal impairment. The separation from the mother, the exposure to painful procedures
      but also routine interventions such as physical examination, diaper changes and bathing
      increase the salivary cortisol level of the newborn compared to the basal state. The
      measurement of salivary cortisol in the newborn therefore has the aim of understanding and
      preventing those stressful conditions that may have long-term side effects. For this reason,
      the lose weight in the first days and double weighing should be a stress practice for the
      newborn.
    

Detailed description: 
      After the phase of early adaptation, newborn must learn quickly to live out of the mother
      uterus. In this phase of life, physiological mechanisms are activated. Newborn loss body
      weight because loss liquid by respiration, feces, urine and not adequate feeding. Body weight
      loss after birth is physiological when is lower than 10% but is also important the evaluation
      of body weight daily trend that must be lower than 5%. If newborn shows physiological body
      weight loss, no treatment will be necessary and rooming-in can continue together with
      exclusively breastfeeding.

      Furthermore, if newborn lose more than 10% of body weight during 48hr of life or more than 5%
      of body weight in a day, a dehydration state will occur that will influence negatively the
      physiological cardio-circulatory and kidney adaptation. In these cases, is important execute
      controls and a specific therapy. When body weight loss is between 7%-10%, usually in
      Neonatology wards it is used double weighing before and after breastfeeding. This practice
      evaluates colostrum quantity that is assumed from infant during feeding and the necessity of
      milk formula integration to prevent an excessive body weight loss. Diuresis is also
      monitored, and parents are informed on the benefits of breastfeeding.

      If body weight loss is greater than 10%, diuresis is monitored weighing the diaper and
      haematological examinations are performed. In this case, it is counselled an artificial milk
      integration after breastfeeding. Discharge can be influenced from the results of the controls
      and must be executed for the security of the newborn.

      Health care providers must not be underestimated the possible allergies to formula milk and
      the mothers that give up breastfeeding after the use of formula milk. The newborn should
      receive breastfeeding from the delivery room. It is good practice, when the milk secretion is
      enough, to attach the infant to a single breast for each feeding and let it suck for 15-20
      minutes. Quantity of milk that newborn assume for each feeding is object of careful
      evaluation. Double weighing consists in weighing newborn before and after feeding: the body
      weight difference is the quantity of milk assumed. In the first day of life, newborn should
      suck 10 gr of colostrum or milk for each feeding. Then starting from the second day of life,
      the quantity of milk assumed must be increased of 10 gr/die for the first week.

      According to scientific revisions, salivary cortisol is a valid method for measuring
      adrenocortical activity in newborns because it is non-invasive in fact the measurement of
      salivary cortisol has been used as a stress marker in newborns since 1992. The mechanism by
      which cortisol induces stress, concerns the hypothalamic-pituitary-adrenal axis. The
      hypothalamus produces the corticotropin-releasing hormone, which stimulates the production of
      adrenocorticotropin by hypophysis. Adrenocorticotropin induces the secretion of
      glucocorticoids such as cortisol by stimulating the cortex of the adrenal gland. An
      appropriate release of cortisol due to stress factor is vital for surviving and the loss of
      this mechanism increase the risk of morbidity and mortality for newborns. However, prolonged
      exposure to a high level of cortisol may increase the risk of cognitive and behavioural
      disorders, hypertension, hyperlipidaemia, insulin resistance, immune deficiency and
      hippocampal impairment. The separation from the mother, the exposure to painful procedures
      but also routine interventions such as physical examination, diaper changes and bathing
      increase the salivary cortisol level of the newborn compared to the basal state. The
      measurement of salivary cortisol in the newborn therefore has the aim of understanding and
      preventing those stressful conditions that may have long-term side effects. For this reason,
      the lose weight in the first days and double weighing should be a stress practice for the
      newborn.
    

Intervention name(s): Evaluation of newborn stress; Evaluation of body weight trend
Intervention type(s): Other; Other
Intervention description(s): Newborn stress will be evaluated by salivary cortisol levels at 48 hr of life. Saliva sample of the newborns will be collected in oral cavity at 48 hr of life. Samples collected will be storage at -80 C for up to 4 months and analysed by analysis laboratory of Poliambulanza Foundation.; Body weight trend between newborns subjected to double weighing or to body weight control will be carried out at 36 hr and 48 hr of life
Observational model: Case-Control
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Caucasian newborns with 37-42 weeks of gestational age and that live in Lombardia.
      
Keywords: Newborn; Salivary Cortisol Level; Double Weghing; Physiological weight loss; Breastfeeding; Stress marker