Five days after a spontaneous vaginal delivery, a woman comes to the emergency room because she has a fever and persistent cramping. The nurse recognizes that the cause of these signs and symptoms may be:

Encourage the newborn to breastfeed every 2 hr. This is because breastfeeding helps the newborn to excrete bilirubin through stool and urine. Breastfeeding also prevents dehydration, which can worsen jaundice. The nurse should also monitor the newborn’s weight, hydration status, and bilirubin levels during phototherapy.

Choice A is wrong because monitoring the newborn’s blood glucose level hourly is not necessary for phototherapy.

Choice B is wrong because applying lotion to the newborn’s skin twice per day can interfere with the effectiveness of phototherapy and increase the risk of skin irritation.

Choice D is wrong because maintaining the newborn in a prone position can increase the risk of sudden infant death syndrome (SIDS) and limit the exposure of skin to light.

Injecting the medication into the vastus lateralis. This is because the vastus lateralis is a large muscle in the thigh that is suitable for intramuscular injections in newborns³. The vitamin K injection helps prevent vitamin K deficiency bleeding, which is a rare but serious condition that can cause bleeding in the brain or other organs¹. The American Academy of Pediatrics recommends that all newborns receive a single intramuscular dose of 0.5 to 1 mg of vitamin K within one hour of birth².

Choice A is wrong because a 21 gauge needle is too large for a newborn's muscle. A 25 or 27 gauge needle is more appropriate.

Choice B is wrong because injecting at a 45-degree angle may not reach the muscle tissue. A 90-degree angle is more appropriate.

Choice C is wrong because injecting 1cc of medication is too much for a newborn's muscle. The recommended dose of vitamin K is 0.5 to 1 mg, which is equivalent to 0.05 to 0.1 mL.