A nurse is assisting in the initiation of phototherapy.
Which nursing action is indicated for the newborn?

Choice A rationale

Elevated maternal serum alpha-fetoprotein (MSAFP) levels can suggest a neural tube defect (NTD), such as spina bifida or anencephaly. Alpha-fetoprotein is a glycoprotein produced by the fetal liver and yolk sac. With an open NTD, this protein leaks from the exposed fetal tissue into the amniotic fluid and subsequently crosses the placenta into the maternal bloodstream, causing the observed elevation.

Choice B rationale

Trisomy 21 (Down syndrome) is typically associated with lower than normal MSAFP levels. MSAFP is part of the quad screen (or triple screen) that screens for common chromosomal abnormalities. Low levels of MSAFP, often combined with abnormal levels of other markers like β-hCG, unconjugated estriol, and inhibin A, suggest an increased risk for this aneuploidy.

Choice C rationale

Phenylketonuria (PKU) is an inherited metabolic disorder where the body cannot properly metabolize the amino acid phenylalanine due to a deficiency of the enzyme phenylalanine hydroxylase. It is not directly associated with elevated MSAFP levels. PKU is screened for in newborns via a heel stick blood test, usually 24 to 48 hours after birth.

Choice D rationale

Hemophilia is an X-linked recessive bleeding disorder caused by a deficiency in specific clotting factors, typically factor VIII (Hemophilia A) or factor IX (Hemophilia B). This condition involves defective hemostasis and is not indicated by an elevated MSAFP. Hemophilia is often diagnosed through specific clotting factor assays.

Choice A rationale

Neonatal hypoglycemia is typically defined as a blood glucose concentration below 40 mg/dL in the first 4 hours of life, or below 45 mg/dL between 4 and 24 hours. Glucose levels of 40 to 45 mg/dL are generally considered the goal range to prevent neurological injury, not the normal lower limit for up to 72 hours post-birth.

Choice B rationale

If a newborn's blood glucose levels remain persistently below 40 mg/dL after initial management (like feeding) or if they develop symptomatic hypoglycemia, intravenous dextrose will be required. A value persistently below 50 mg/dL is concerning, but the 40 mg/dL threshold is often the critical point for initiating IV glucose when oral methods fail.

Choice C rationale

The umbilical cord provides the fetus with a continuous supply of glucose via the placenta from the mother. Upon umbilical cord clamping, this maternal glucose supply is abruptly interrupted, requiring the newborn's immature metabolic systems to take over glucose homeostasis. This sudden loss of exogenous glucose is a primary factor in transient newborn hypoglycemia.

Choice D rationale

Frequent breastfeeding provides the newborn with a readily available source of lactose, which is metabolized into glucose, thereby promoting the stability of their blood glucose levels. Early and frequent feeding is the primary intervention for transient hypoglycemia in newborns who are able to feed, utilizing the oral route for caloric intake.

Choice E rationale

Transient hypoglycemia is a common and expected physiological adaptation in term newborns during the initial hours after birth. The abrupt cessation of maternal glucose supply necessitates the newborn's activation of gluconeogenesis and glycogenolysis, which may temporarily be insufficient, leading to a mild, self-limiting drop in blood glucose.

Choice F rationale

Skin-to-skin contact immediately after birth is vital as it prevents cold stress. When a newborn is cold, they must expend energy (calories) to produce heat, which consumes glucose, potentially leading to or exacerbating hypoglycemia. Thermoregulation thus indirectly stabilizes blood glucose levels by conserving energy.