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: Vibroacoustic stimulation is a technique that uses sound to stimulate the fetus and elicit a response. It is sometimes used in conjunction with the nonstress test (NST), not the CST. The NST measures the fetal heart rate (FHR) in response to fetal movement, while the CST measures the FHR in response to uterine contractions.

Choice B reason: A negative CST result means that the FHR does not show any late decelerations during at least three contractions in a 10-minute period. Late decelerations are decreases in the FHR that begin after the peak of a contraction and return to the baseline after the contraction ends. They indicate uteroplacental insufficiency, which means that the placenta is not delivering enough oxygen and nutrients to the fetus. A negative CST result is reassuring and suggests that the fetus is well-oxygenated and can tolerate labor².

Choice C reason: The CST is not an invasive test, as it does not involve inserting any instruments or devices into the uterus or the fetus. However, it does require stimulating contractions, either by giving the pregnant woman oxytocin (a hormone that causes uterine contractions) or by having her rub her nipples (which also releases oxytocin). The contractions can be uncomfortable and may trigger preterm labor in some cases.

Choice D reason: The CST is not more effective than the NST if the membranes have already been ruptured. In fact, the CST is contraindicated (not recommended) in women who have ruptured membranes, as it can increase the risk of infection and bleeding. The NST is a safer and simpler alternative to the CST, as it does not require stimulating contractions. However, the NST may not be as reliable as the CST in detecting fetal compromise.

Choice A reason: Genetic changes and anomalies are not the most dangerous effect, as they are rare and not directly caused by smoking. Smoking can increase the risk of some birth defects, such as cleft lip and cleft palate, but these are not genetic changes and can be corrected by surgery. Smoking can also cause chromosomal abnormalities in the eggs, but these usually result in miscarriage or stillbirth, not live births.

Choice B reason:Maternal smoking is a significant risk factor for intrauterine growth restriction (IUGR). Nicotine and carbon monoxide from cigarettes reduce oxygen supply to the fetus, leading to lower birth weights and smaller body lengths.

Choice C reason: Fetal addiction to the substance inhaled is not the most dangerous effect, as it is not permanent and can be treated by medication and supportive care. Smoking can expose the fetus to nicotine, carbon monoxide, and other harmful chemicals, which can cross the placenta and affect the fetal brain and nervous system. Smoking can also cause withdrawal symptoms in the newborn, such as irritability, tremors, and difficulty feeding.

Choice D reason:Although prenatal exposure to smoking can affect neurodevelopment and is associated with behavioral issues, extensive central nervous system damage is not the most immediate or dangerous effect. The most critical concern remains intrauterine growth restriction.