A 32-year-old primigravida is admitted with a diagnosis of ectopic pregnancy. Nursing care is based on the knowledge that:

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.

Choice A reason: Cerebral compression is the cause of early decelerations, as it reflects the fetal head compression during uterine contractions. Early decelerations are decreases in the FHR that begin and end with the onset and end of a contraction, respectively. They are symmetrical and mirror the shape of the contraction. Early decelerations are normal and benign, as they indicate that the fetus is responding to the increased intracranial pressure and maintaining adequate oxygenation.

Choice B reason: Cord compression is not the cause of early decelerations but of variable decelerations. Variable decelerations are abrupt and irregular decreases in the FHR that vary in onset, duration, and depth. They are usually caused by the umbilical cord being compressed or occluded by the fetal body, the maternal pelvis, or the uterine contractions. Variable decelerations can indicate fetal distress or hypoxia, especially if they are severe, frequent, or prolonged.

Choice C reason: Uteroplacental insufficiency is not the cause of early decelerations, but of late decelerations. 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 are symmetrical and have a gradual onset and recovery. They are usually caused by the reduced blood flow and oxygen delivery to the placenta and the fetus due to maternal or fetal factors. Late decelerations can indicate fetal distress or hypoxia, and require immediate intervention.

Choice D reason: Spontaneous rupture of membranes is not the cause of early decelerations, but it can be a risk factor for cord compression and variable decelerations. Spontaneous rupture of membranes is the breaking of the amniotic sac and the release of the amniotic fluid, which usually occurs during labor or shortly before it. Spontaneous rupture of membranes can cause the umbilical cord to prolapse or slip into the vagina, where it can be compressed or kinked by the fetal head or the contractions.