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Prenatal and Neonatal Adaptations with a Focus on the Respiratory System
Author(s) -
Vannucchi CI,
Silva LCG,
Lúcio CF,
Regazzi FM,
Veiga GAL,
Angrimani DS
Publication year - 2012
Publication title -
reproduction in domestic animals
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.546
H-Index - 66
eISSN - 1439-0531
pISSN - 0936-6768
DOI - 10.1111/rda.12078
Subject(s) - medicine , metabolic acidosis , hypoxia (environmental) , respiratory distress , acidosis , respiratory system , respiratory acidosis , pregnancy , apgar score , fetus , anesthesia , obstetrics , physiology , biology , oxygen , chemistry , organic chemistry , genetics
Contents Among the modifications that occur during the neonatal period, pulmonary development is the most critical. The neonate's lungs must be able to perform adequate gas exchange, which was previously accomplished by the placenta. Neonatal respiratory distress syndrome is defined as insufficient surfactant production or pulmonary structural immaturity and is specifically relevant to preterm newborns. Prenatal maternal betamethasone treatment of bitches at 55 days of gestation leads to structural changes in the neonatal lung parenchyma and consequently an improvement in the preterm neonatal respiratory condition, but not to an increase in pulmonary surfactant production. Parturition represents an important challenge to neonatal adaptation, as the uterine and abdominal contractions during labour provoke intermittent hypoxia. Immediately after birth, puppies present venous mixed acidosis (low blood p H and high dioxide carbon saturation) and low but satisfactory A pgar scores. Thus, the combination of physiological hypoxia during birth and the initial effort of filling the pulmonary alveoli with oxygen results in anaerobiosis. As a neonatal adaptation follow‐up, the Apgar analysis indicates a tachypnoea response after 1 h of life, which leads to a shift in the blood acid–base status to metabolic acidosis. One hour is sufficient for canine neonates to achieve an ideal A pgar score; however, a haemogasometric imbalance persists. Dystocia promotes a long‐lasting bradycardia effect, slows down A pgar score progression and aggravates metabolic acidosis and stress. The latest data reinforce the need to accurately intervene during canine parturition and offer adequate medical treatment to puppies that underwent a pathological labour.