A woman who is trying to get pregnant tells the nurse that she was very disappointed several months ago when she was informed that her positive pregnancy test was a false positive. Which method of determining pregnancy provides the greatest degree of accuracy?

Choice A rationale

Passive immunity provided by maternal antibodies crossing the placenta and through breast milk protects newborns in the first months of life, offering initial defense against communicable diseases.

Choice B rationale

Antiinfectants effectiveness against microbes does not apply; newborns rely on passive immunity as their adaptive immune system matures, not unresistant antiinfectants.

Choice C rationale

Active immunity develops over several months to years in newborns, as their immune system gradually encounters pathogens and develops specific responses.

Choice D rationale

While neutrophils are part of the innate immune system, they may still be immature and insufficient in preventing infections in neonates without maternal antibody support.

Choice A rationale: Hemoglobin of 10.4 g/dL is slightly below the normal range for non-pregnant women (12-16 g/dL) but may be acceptable postpartum. Mild anemia can cause fatigue but doesn't explain the new-onset headache, dizziness, or elevated blood pressure.

Choice B rationale: Platelet count of 150,000/mm³ is within the normal range (150,000-450,000/mm³). Thrombocytopenia would be a concern if platelets were below 150,000/mm³, as it can cause bleeding, but it doesn't correlate with the client's symptoms.

Choice C rationale: New-onset headache, especially unrelieved by ibuprofen, is concerning. Postpartum preeclampsia can present with a severe headache. The headache, combined with elevated blood pressure, requires further investigation for potential complications like cerebral edema or hypertensive encephalopathy.

Choice D rationale: Vomiting yellow fluid may indicate gastrointestinal distress or bile. In the context of right upper quadrant pain and elevated blood pressure, it raises concerns for conditions like HELLP syndrome or liver involvement. Further evaluation is needed to rule out these possibilities.

Choice E rationale: Right upper quadrant pain can be a symptom of postpartum preeclampsia or HELLP syndrome, where liver enzymes are elevated. Pain in this area combined with other symptoms like headache, nausea, and elevated blood pressure warrants further investigation.

Choice F rationale: Seeing flashing lights is a potential sign of visual disturbances related to severe hypertension or preeclampsia. It can be an indication of impending eclampsia or other complications like retinal detachment or cerebral edema. This symptom must be promptly evaluated.

Choice G rationale: Elevated blood pressure (169/104 mm Hg) is a critical finding. Normal postpartum blood pressure should be below 140/90 mm Hg. Severe hypertension postpartum can lead to complications like preeclampsia, eclampsia, or stroke. Immediate medical evaluation is required.

Choice H rationale: Iron supplementation is common postpartum to address mild anemia and restore iron levels depleted during pregnancy and delivery. While important for recovery, it does not explain the new-onset headache, elevated blood pressure, or other symptoms reported by the client.