What is the most dangerous effect on the fetus of a mother who smokes cigarettes while pregnant?

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.

Choice A reason: An FHR greater than 110 beats/min is not a sufficient indicator of fetal well-being during labor. The normal range of FHR is between 110 and 160 beats/min, but it can vary depending on the gestational age, fetal activity, and maternal factors. A high or low FHR may indicate fetal distress or compromise.

Choice B reason: Maternal pain control is not a direct measure of fetal well-being during labor. However, maternal pain can affect the FHR indirectly by causing maternal stress, anxiety, or hyperventilation, which can alter the blood flow and oxygen delivery to the fetus. Therefore, adequate pain management is important for both maternal and fetal health.

Choice C reason: The response of the FHR to UCs is the most reliable and accurate way of assessing fetal well-being during labor. UCs can cause temporary reductions in the blood flow and oxygen supply to the fetus, which can affect the FHR. A normal response of the FHR to UCs is either no change or a slight increase (acceleration), which indicates a well-oxygenated and resilient fetus. An abnormal response of the FHR to UCs is a decrease (deceleration), which indicates a compromised or hypoxic fetus.

Choice D reason: Accelerations in the FHR are not a definitive measure of fetal well-being during labor. Accelerations are transient increases in the FHR above the baseline, usually caused by fetal movement, stimulation, or UCs. Accelerations are generally reassuring and indicate a responsive and well-oxygenated fetus, but they are not always present or consistent. The absence of accelerations does not necessarily mean fetal distress, as some fetuses may have periods of sleep or reduced activity.