A woman gave birth to a 7-pound, 3-ounce infant boy 2 hours ago. The nurse determines that the woman's bladder is distended because her fundus is now 3 cm above the umbilicus and to the right of the midline. In the immediate postpartum period, the most serious consequence likely to occur from bladder distention is:

A) Bacteria that synthesize vitamin K are not present in the newborn's intestinal tract:
Newborns are born with a sterile gastrointestinal tract, meaning they do not yet have the intestinal bacteria necessary to synthesize vitamin K. Vitamin K is essential for the activation of clotting factors, and without sufficient vitamin K, newborns are at risk for bleeding disorders, particularly a condition known as vitamin K deficiency bleeding (VKDB). Administering vitamin K by injection shortly after birth ensures the baby has adequate levels to prevent bleeding.
B) Vitamin K prevents the synthesis of prothrombin in the liver and must be given by injection:
This statement is incorrect. Vitamin K does not prevent the synthesis of prothrombin; rather, it is essential for the liver to synthesize clotting factors, including prothrombin. The injection of vitamin K in newborns is necessary to provide adequate levels of vitamin K to support proper blood clotting, as newborns cannot produce enough on their own at birth due to the absence of gut bacteria that normally produce it.

C) The supply of vitamin K is inadequate for at least 12 months, and the newborn must be supplemented throughout infancy:
While it is true that newborns have a limited supply of vitamin K at birth, this deficiency is typically addressed with a single injection given shortly after birth. Supplementing vitamin K throughout infancy is generally not required, as the infant's gastrointestinal tract will start to develop the necessary bacteria to synthesize vitamin K within the first few weeks to months of life. The first dose of vitamin K prevents bleeding disorders, and in most cases, additional supplementation is not necessary.

D) Most mothers have a diet deficient in vitamin K, which results in the infant being deficient:
While maternal diet does play a role in the newborn's initial vitamin K levels, it is not the primary reason for the deficiency. Vitamin K deficiency in newborns is primarily due to the lack of gut bacteria necessary to produce it, rather than maternal diet. The practice of administering vitamin K to all newborns ensures that they receive adequate levels to prevent bleeding, regardless of maternal dietary intake.

A) 2 to 3 oz (60 to 90 mL):
To determine the appropriate amount of formula for this infant, first calculate the total fluid requirements for the day. The infant weighs 6 lb (2722 g), and newborns typically need 73 mL of fluid per pound of body weight per day.
6 lb × 73 mL = 438 mL of fluid required daily.
Since the infant is fed every 4 hours, this equates to approximately 6 feedings in a 24-hour period.
438 mL ÷ 6 feedings = 73 mL per feeding.
Converting this to ounces (since 1 oz = 30 mL), the infant would need about 2.5 oz per feeding. Therefore, 2 to 3 oz (60 to 90 mL) per feeding is appropriate to meet the infant's daily fluid needs.

B) 1 to 1.5 oz (30 to 45 mL):
This amount is insufficient for the infant’s daily fluid needs. At 1 to 1.5 oz per feeding, the total intake for the day would be only 180 to 270 mL, which is well below the required 438 mL. This could lead to dehydration and inadequate nourishment.

C) 4 to 5 oz (120 to 150 mL):
This amount is excessive for a 3-day-old infant. Newborns typically consume much smaller amounts at each feeding due to their smaller stomach capacity. Overfeeding could lead to discomfort and potential digestive issues.

D) 3 to 4 oz (90 to 120 mL):
While this range is closer to the required amount, it is still slightly too much for a 3-day-old infant. At this age, the recommended amount is closer to 2.5 oz per feeding, so 3 to 4 oz may be excessive and could contribute to overfeeding, which might be uncomfortable for the infant.