A nurse is caring for a client who is experiencing severe pain during active labor.
Which of the following medications should the nurse plan to administer and document in the client's medical record?

Choice A rationale

At 10 weeks of gestation, the external genitalia of the fetus are not yet fully differentiated or large enough to be reliably visualized and identified as male or female on an ultrasound. Fetal sex determination is typically more accurate later in pregnancy, usually after 16-20 weeks, when anatomical structures are more developed and distinct.

Choice B rationale

While some major structural congenital anomalies might be detectable at 10 weeks, a comprehensive and detailed assessment for a wide range of congenital anomalies is usually performed during the anomaly scan, which is typically conducted between 18 and 22 weeks of gestation. Fetal development is still ongoing at 10 weeks.

Choice C rationale

An ultrasound performed in the first trimester, particularly around 10 weeks, is highly accurate for estimating gestational age and, consequently, the expected delivery date. This is because fetal growth is very consistent during this period, allowing for precise measurements such as crown-rump length to determine gestational age within a small margin of error.

Choice D rationale

Assessment of amniotic fluid volume, often quantified using the amniotic fluid index (AFI) or deepest vertical pocket, is more commonly performed in the second and third trimesters of pregnancy. At 10 weeks, the amniotic fluid volume is relatively small, and its adequacy is not typically a primary focus of an early ultrasound unless there are specific concerns.

The nurse should further evaluate respiratory characteristics and muscle tone to determine if the newborn is experiencing a complication.

Rationale for correct answers
Respiratory characteristics are critical to assess because irregular and shallow breathing in a newborn can indicate neurological or respiratory dysfunction. Normal neonatal respiratory rate ranges from 30 to 60 breaths per minute with regular pattern; deviations may signal distress or central nervous system issues. Muscle tone evaluation is essential since increased tone with tremors suggests possible neurologic irritability or withdrawal. Normal newborn muscle tone should be moderate, neither hypotonic nor hypertonic, with symmetrical movement. These signs correlate with the high-pitched cry, tremors, and exaggerated reflexes noted, which may indicate neurological complications such as withdrawal syndrome or hypoxic-ischemic encephalopathy.

Rationale for incorrect answers
Heart rate (A) is important but was not reported abnormal; normal neonatal heart rate ranges from 120 to 160 beats per minute and the absence of murmurs suggests no cardiac compromise. Temperature (C) is less urgent as mucous membranes are moist and skin warm and dry, indicating stable thermoregulation; normal newborn temperature is 36.5–37.5°C. Feeding patterns (D) appear adequate with no difficulty reported, making this less immediately concerning.

Rationale for incorrect answers
Moro reflex (A) and Babinski reflex (B) are both present and exaggerated, which may be reactive but less specific for immediate concern than muscle tone abnormalities. Skin color (D) is normal without cyanosis or jaundice, reducing the likelihood of hypoxia or hemolytic issues.

Take home points

• Respiratory pattern irregularities in newborns may indicate neurological or respiratory dysfunction.
• Abnormal muscle tone and tremors are key signs of potential neurological complications.
• Normal heart rate, temperature, feeding, and skin color reduce likelihood of cardiac or systemic illness.
• Reflex exaggeration alone is less specific than muscle tone and respiratory changes for early complication detection.