The nurse is counseling a woman who wants to become pregnant. The woman tells the nurse that she has a 28-day menstrual cycle and the first day of her menstrual period was January 8. The nurse correctly calculates that the woman's next fertile period is?

Choice A reason: The NST has no known contraindications, as it is a non-invasive and safe test that does not stimulate uterine contractions or cause fetal distress. It is the most widely used method of antepartum fetal surveillance.

Choice B reason: The NST is not slightly more expensive than the CST, as it requires less time and equipment. The NST usually takes 20 to 40 minutes, while the CST may take up to 2 hours. The NST only needs a fetal monitor, while the CST also needs an intravenous line and oxytocin infusion.

Choice C reason: The NST does not have fewer false-positive results than the CST, as it has a higher rate of nonreactive results that may indicate fetal compromise when there is none. A nonreactive NST is one that does not show at least two accelerations of the fetal heart rate of 15 beats per minute or more lasting 15 seconds or more in a 20-minute period.

Choice D reason: The NST is not more sensitive in detecting fetal compromise than the CST, as it has a lower predictive value for fetal well-being. A reactive NST is one that shows at least two accelerations of the fetal heart rate of 15 beats per minute or more lasting 15 seconds or more in a 20-minute period. However, a reactive NST does not rule out the possibility of fetal hypoxia or acidosis.

Choice A reason: Raising the woman's legs is not the best initial response, as it may worsen the dizziness and light-headedness. This is because raising the legs can increase the blood flow to the lower extremities and decrease the blood flow to the brain, which can cause hypotension (low blood pressure) and hypoxia (low oxygen) in the woman and the fetus.

Choice B reason: Having the woman breathe into a paper bag is not the best initial response, as it may not address the underlying cause of the dizziness and light-headedness. This technique is usually used for hyperventilation (rapid breathing), which can cause respiratory alkalosis (high blood pH) and reduce the carbon dioxide levels in the blood. However, the woman may not be hyperventilating, but rather experiencing supine hypotensive syndrome (low blood pressure when lying on the back) due to the pressure of the uterus on the inferior vena cava (a large vein that returns blood to the heart)².

Choice C reason: Turning the woman on her side is the best initial response, as it can relieve the dizziness and light-headedness by improving the blood flow to the brain and the fetus. This is because turning the woman on her side can reduce the pressure of the uterus on the inferior vena cava and increase the cardiac output (the amount of blood pumped by the heart) and the blood pressure. The left lateral position is preferred, as it can also optimize the placental perfusion (the blood flow to the placenta) and the fetal oxygenation.

Choice D reason: Assessing the woman's blood pressure and pulse is an important response, but not the first one. After turning the woman on her side, the nurse should monitor the vital signs and the fetal heart rate to evaluate the condition of the woman and the fetus. The nurse should also check for other signs and symptoms of supine hypotensive syndrome, such as nausea, sweating, and visual disturbances.