A nurse is caring for a newborn who exhibits signs of hypotonicity, weak reflexes, and a weak cry.

Preterm infants are at the highest risk for respiratory distress syndrome (RDS), a common breathing disorder that affects newborns.RDS occurs because of a lack of surfactant, a foamy substance that keeps the lungs fully expanded.Surfactant is usually produced by the lungs during the third trimester of pregnancy, which starts after the 26th week.Therefore, babies born before their due date, especially before 28 weeks of pregnancy, are more likely to have RDS.

Choice B is wrong because macrosomic babies, or babies who are larger than average at birth, are not at increased risk for RDS.

However, they may have other complications such as birth injuries or low blood sugar levels.

Choice C is wrong because post-term infants, or babies who are born after 42 weeks of pregnancy, are not at increased risk for RDS.

However, they may have other complications such as meconium aspiration or low blood sugar levels.

Choice D is wrong because newborns with hyperbilirubinemia, or high levels of bilirubin in the blood, are not at increased risk for RDS.

However, they may have other complications such as jaundice or brain damage.

Other risk factors for RDS include being a white male, having multiple fetuses, having a mother with diabetes, and having premature rupture of membranes (PROM).

Hypoglycemia is a condition where the blood glucose level is too low, which can affect the brain and nervous system function.Hypoglycemia can cause symptoms such as hypotonia (low muscle tone), weak reflexes, and a weak cry in newborns.

These symptoms are due to the lack of energy supply to the muscles and nerves.

Choice B. Hyperbilirubinemia is wrong because it is a condition where the blood level of bilirubin, a waste product from red blood cell breakdown, is too high.

Hyperbilirubinemia can cause jaundice (yellowing of the skin and eyes), but not hypotonia, weak reflexes, or a weak cry.

Choice C. Preterm birth is wrong because it is a condition where the baby is born before 37 weeks of gestation.

Preterm birth can cause many complications, such as respiratory distress, bleeding in the brain, and infection, but not hypotonia, weak reflexes, or a weak cry.

Choice D. Macrosomia is wrong because it is a condition where the baby is larger than average at birth, usually weighing more than 4 kg (8 lb 13 oz).

Macrosomia can cause problems during delivery, such as shoulder dystocia, birth injury, and low blood sugar, but not hypotonia, weak reflexes, or a weak cry.