thetic gases cross the placenta and may sedate the fetus). High-risk pregnancies for asphyxia neonatorum include:
- maternal age of less than 16 years old or over 40 years old
- low socioeconomic status
- maternal illnesses, such as diabetes, hypertension, Rh-sensitization, severe anemia
- mothers with previous abortions, stillbirths, early neonatal deaths, or preterm birth
- lack of prenatal care
- abnormal fetal presentation or position
- alcohol abuse and smoking by the mother
- severe fetal growth retardation
- preterm labor
The symptoms of asphyxia neonatorum are bluish or gray skin color (cyanosis), slow heartbeat (bradycardia), stiff or limp limbs ( hypotonia ), and a poor response to stimulation.
When to call the doctor
Pregnant women who are at high risk of delivering newborns with asphyxia neonatorum should arrange for a close follow-up of their pregnancy with their obstetrician.
Diagnosis can be objectively assessed using the Apgar score—a recording of the physical health of a newborn infant, determined after examination of the adequacy of respiration, heart action, muscle tone, skin color, and reflexes. Normally, the Apgar score is of 7 to 10. Infants with a score between 4 and 6 have moderate depression of their vital signs while infants with a score of 0 to 3 have severely depressed vital signs and are at great risk of dying unless actively resuscitated.
The treatment for asphyxia neonatorum is resuscitation of the newborn. All medical delivery rooms have adequate resuscitation equipment should an infant not breathe well at delivery. Between 1970 and 2000, neonatal resuscitation has evolved from disparate teaching methods to organized programs. The most widely used procedure is the Neonatal Resucitation Program, supported by the American Academy of Pediatrics (AAP) and the American Heart Association (AHA).
If stimulation fails to initiate regular respiration in the newborn, the attending physician attempts resuscitation. He may decide first to gently suction the oropharynx—the area of the throat at the back of the mouth, with a soft catheter. When stimulation and a clear airway do not result in adequate respiration, the physician may give 100 percent oxygen via a face mask. If the infant is still not breathing, some form of artificial ventilation is then required. The usual method is to use mask ventilation with a resuscitator. The mask is applied tightly to the infant's face. If this procedure fails, the infant can be intubated with a endotracheal tube to which the resuscitator can then be connected. The more severe the fetal asphyxia, the longer it will take before the infant starts to breathe spontaneously. If the infant does not breathe despite adequate ventilation, or if the heart rate remains below 80 beats per minute, the physician can give an external cardiac massage using two fingers to depress the lower sternum at approximately 100 times a minute while continuing with respiratory assistance. Adrenaline may also be administered to increase cardiac output. Once the infant starts breathing, he or she is transferred to a nursery for observation and further assessment. Temperature, pulse and respiratory rate, color, and activity are recorded, and blood glucose levels checked for at least four hours.
Treatment may also include the following:
- giving the mother extra amounts of oxygen before delivery
- medications to support the baby's breathing and sustain blood pressure
- extracorporeal membrane oxygenation (ECMO)
ECMO is a technique similar to a heart-lung bypass machine, which assists the infant's heart and lung functions with use of an external pump and oxygenator.
If an inadequate supply of oxygen from the placenta is detected during labor, the infant is at high risk for asphyxia, and an emergency delivery may be attempted either using forceps or by cesarean section.
The prognosis for asphyxia neonatorum depends on how long the new born is unable to breathe. For example, clinical studies show that the outcome of babies with low five-minute Apgar scores is significantly better than those with the s