A first-time father is changing the diaper of his 1-day-old daughter. He asks the nurse, "What is this black, sticky stuff in her diaper?" The nurse's best response is:

Choice A: This is incorrect because pointing out how lucky she is to have a healthy baby may invalidate her feelings and make her feel guilty or ashamed. The nurse should acknowledge and respect the client's emotions and avoid making judgments or comparisons.

Choice B: This is incorrect because assessing her for pain is not the first action that the nurse should take. Although pain may be a factor that contributes to the client's emotional state, it is not the primary cause of her crying. The nurse should first establish rapport and trust with the client and then assess her physical and psychological needs.

Choice C: This is incorrect because explaining that she is experiencing postpartum blues may be premature and inaccurate. Postpartum blues are mild and transient mood changes that occur in up to 80% of women within the first few days after childbirth. They are characterized by tearfulness, irritability, anxiety, and mood swings. However, the nurse should not assume that the client has postpartum blues without performing a thorough assessment and ruling out other possible causes of her crying, such as postpartum depression, anxiety, or trauma.

Choice D: This is the correct answer because allowing her time to express her feelings is the most appropriate and empathetic action that the nurse should take first. The nurse should listen actively and attentively to the client and provide emotional support and reassurance. The nurse should also use open-ended questions and reflective statements to facilitate communication and explore the client's concerns and coping strategies.

Choice A: This is incorrect because weight less than the 10th percentile (SGA) means that the infant is smaller than expected for the gestational age, but not necessarily low birth weight. SGA infants may have intrauterine growth restriction due to maternal, placental, or fetal factors, but they may also be constitutionally small. SGA infants are at risk for hypoglycemia, hypothermia, polycythemia, and perinatal asphyxia.

Choice B: This is incorrect because weight greater than the 90th percentile means that the infant is larger than expected for the gestational age, but not necessarily high birth weight. Infants with weight greater than the 90th percentile are called large for gestational age (LGA) or macrosomic. LGA infants may have maternal diabetes, genetic factors, or post-term pregnancy as causes, but they may also be constitutionally large. LGA infants are at risk for birth trauma, shoulder dystocia, hypoglycemia, and respiratory distress.

Choice C: This is incorrect because weight between the 10th and 90th percentile means that the infant is appropriate for the gestational age (AGA), but not necessarily normal birth weight. AGA infants have a weight that matches their gestational age and are considered healthy and well-nourished. However, some AGA infants may have low or high birth weight depending on their gestational age at birth.

Choice D: This is the correct answer because low birth weight (LBW) is defined as a weight of 2500g or less at birth, regardless of the gestational age. LBW infants may be preterm (born before 37 weeks of gestation), term (born between 37 and 42 weeks of gestation), or post-term (born after 42 weeks of gestation). LBW infants are at risk for infection, bleeding, jaundice, and neurodevelopmental problems.