Perinatal asphyxia

Perinatal asphyxia is a serious medical condition involving oxygen deprivation. It occurs when a newborn infant does not receive enough oxygen during the birth process. This shortage must last long enough to cause physical harm to the body. While it can affect many organs, the brain is the most vulnerable. The condition is also defined by an inability to start or maintain breathing after delivery. It can occur anytime from the 28th week of pregnancy until seven days after birth.

The World Health Organization (WHO) uses specific markers to identify this condition. One sign is profound metabolic acidosis. This means the blood becomes too acidic, showing a pH level below 7.20 in the umbilical cord. Doctors also look at the Apgar score, which measures a newborn's health. A score of 3 at the fifth minute is a significant indicator. Other signs include neurological issues or dysfunction in multiple organ systems. Without quick action, the lack of oxygen can lead to cardiac arrest.

There are two main categories of causes for this condition. The first group is called antepartum causes, which happen before birth. These include low maternal blood pressure or heart disease in the mother. It can also happen if the placenta separates too early. The second group is called intrapartum causes, which occur during the actual delivery. These include a prolonged delivery or the umbilical cord knotting around the infant's neck. Inadequate relaxation of the uterus due to excess oxytocin can also be a factor.

Many risk factors can increase the chance of perinatal asphyxia. These include being a very young or elderly mother. It can also involve multiple births or low birth weight. Medical issues like eclampsia, pre-eclampsia, or maternal anemia are also risks. When it occurs, the infant may show signs like cyanosis, which is a poor or blue color. They may also show low muscle tone or poor responsiveness. In severe cases, it can lead to hypoxic ischemic encephalopathy or brain bleeding.

Medical professionals follow specific steps to treat a baby through resuscitation. First, they must establish an open airway, sometimes using suction or a tube. Next, they focus on breathing through methods like a bag and mask. Third, they address circulation by using chest compressions or medications. Doctors may use adrenaline, also called epinephrine, to help the heart. They might also use saline solution if the baby has low blood volume. If the baby survives, they are usually moved to a neonatal intensive care unit.

Scientific research has changed how doctors provide oxygen to newborns. For a long time, there was a debate about using 100% oxygen. However, researchers found that high oxygen levels can create oxygen free radicals. These radicals can cause a type of reperfusion injury after the oxygen shortage ends. A researcher named Ola Didrik Saugstad helped change this approach. His work led to new international guidelines in 2010. These guidelines now recommend using normal air instead of 100% oxygen.

The impact of this condition is quite large on a global scale. The WHO estimates that 4 million neonatal deaths happen yearly due to birth asphyxia. This represents 38% of all deaths for children under five years of age. For babies born at full term, the rate is 2 to 10 per 1,000 births. It is even more common in premature births. In the United States, it was once the tenth leading cause of death for newborns.

There is also a significant legal and medical debate regarding the diagnosis. Because the term can lack precision, some modern doctors avoid using it. In legal cases, attorneys often argue that asphyxia is a preventable error. They suggest it is a cause of conditions like cerebral palsy. However, groups like the American Congress of Obstetricians and Gynecologists disagree. They believe conditions like cerebral palsy often come from issues before or during birth that are not always preventable.