Which infant would be more likely to have Rh incompatibility?

An Apgar score of 10 at 1 minute after birth indicates that the infant is having no difficulty adjusting to extrauterine life but who should be assessed again at 5 minutes after birth. The Apgar score is a scoring system that evaluates the health of newborns at 1 and 5 minutes after birth based on five criteria: appearance, pulse, grimace, activity, and respiration. Each criterion is scored from 0 to 2, and the total score ranges from 0 to 10. A score of 7 to 10 is considered reassuring, a score of 4 to 6 is moderately abnormal, and a score of 0 to 3 is concerning.

Choice A is wrong because an Apgar score of 10 at 1 minute does not mean that the infant needs no further testing. The infant should still be assessed again at 5 minutes and monitored for any signs of distress or complications.

Choice B is wrong because an Apgar score of 10 at 1 minute does not indicate an infant in severe distress who needs resuscitation. An Apgar score of 0 to 3 would indicate a concerning condition that may require immediate intervention.

Choice C is wrong because an Apgar score of 10 at 1 minute does not predict a future free of neurologic problems. The Apgar score alone cannot be considered as evidence of, or a consequence of, asphyxia or brain injury; it does not predict individual neonatal mortality or neurologic outcome; and it should not be used for that purpose.

Normal ranges for each criterion are as follows:

• Appearance (color): pink all over (2 points), body pink but extremities blue (1 point), blue, bluish-gray, or pale all over (0 points)
• Pulse (heart rate): greater than 100 beats per minute (2 points), less than 100 beats per minute (1 point), absent (0 points)
• Grimace (response to stimulation): cough or sneeze, cry and withdrawal of foot with stimulation (2 points), facial movement/grimace with stimulation (1 point), absent (0 points)
• Activity (muscle tone): active movement (2 points), limbs flexed (1 point), limp or floppy (0 points)
• Respiration (breathing): good, strong cry (2 points), irregular, weak crying (1 point), absent (0 points)

Vernix caseosa is a cheese-like, whitish substance that fuses with the epidermis and serves as a protective coating for the newborn.

Some possible explanations for the other choices are:

• Choice B. Surfactant is a protein that lines the alveoli of the infant’s lungs and helps prevent them from collapsing.
• Choice C. Caput succedaneum is a swelling of the tissue over the presenting part of the fetal head caused by pressure during delivery.
• Choice D. Acrocyanosis is a bluish discoloration of the hands and feet due to reduced peripheral circulation.

Normal ranges for vernix caseosa are not applicable as it varies depending on the gestational age and skin maturity of the newborn. However, it is usually more abundant in preterm infants than in term or post-term infants.