What impact does cold stress have on newborns immediately after birth?

Cold stress significantly affects newborns immediately after birth by decreasing oxygen tension and increasing metabolic acidosis. When a newborn is exposed to cold stress, their body temperature drops, leading to a series of physiological responses.

As the newborn struggles to maintain its core temperature, the body uses increased metabolic energy through mechanisms like shivering and non-shivering thermogenesis. However, this increased metabolism can lead to an increased demand for oxygen. If the oxygen supply cannot meet this demand due to the stressful situation, the baby may experience decreased oxygen tension, meaning the amount of oxygen available in the blood decreases.

Furthermore, as oxygen availability diminishes, the body can switch to anaerobic metabolism, creating lactic acid as a byproduct. This results in metabolic acidosis, a condition characterized by an increase in acidity in the body's fluids. This shift in biochemical processes can adversely affect the newborn's overall health, highlighting the importance of maintaining normothermia immediately after birth to prevent these complications.

The impact of cold stress therefore emphasizes the necessity of prompt and effective warming interventions to support the newborn's transition to extrauterine life.